Is Your Laser Level Really Level? How to Check

[@alext9067]

Roger is one serious hombre. All his videos are spot on. Excellent job as always.

[@johnwetzel5248]

Hi Roger. Great video! Also, greetings from SC in the USA! I am a professional Land Surveyor, and there is an interesting bit that you missed that is very handy for you and your viewers to know. That is, that when you put up your tape, you should begin with your laser exactly (give or take a few inches in your 10 ft example) halfway between the two pieces of tape. Why? Because the tops of the tape will then be exactly level EVEN IF your laser level is out of true. Why is that (you might well ask)? Because the laser line that is supposed to be perfectly level is instead "pointing uphill" (slightly) or "downhill" slightly., regardless of what direction it is pointing. IF you do that, you can then put your level really close to one of the tape pieces, and if you are off the other one, you will know the error per distance exactly. If the tapes are 10 feet apart, and you are within a foot of one tape, the error at the other tape is the error in 9 feet. You should start with a measurement that has no error (because it is the same looking both ways because the distances match). Then the second set-up shows all the error at the more distant tape. The most important thing about this comment however, is that it allows you (in a jam) to realize that you can transfer accurate elevations from one spot to another, WITHOUT a perfectly adjusted laser. You just need to be halfway between the two measuring points. How do I know this is true? Because in my work, we utilize 30X telescopes that use the same "free swinging weight with a prism attached" tech that the lasers use. When the swinging prism swings, our telescope crosshair moves up and down, just as the laser level line does if you tap it gently. Our instruments (they are called "survey grade levels) do get out of adjustment. We set two stakes in the ground 360 feet (or 120 meters ) apart. We put the instrument we are checking halfway between them (+ or minus a few feet, we step it off because that is close enough). We then use the instrument to read a grade rod on each stake, which gives us the difference in height between the two stakes. At that distance, we can read down to about 2mm. Knowing that the difference is accurate (because any error is the same looking both ways) we then set up a few feet away from one stake, and repeat the process. If the difference is the same, our instrument is in good adjustment. If it is different, we move the crosshair up or down to obtain a reading on the far grade rod that will make the difference correct (we are so near the near stake that we won't have enough error on it to matter). Then, the process is repeated to verify that all is well. In other words, when a survey level, (or a laser level) is in good adjustment, it hits the same spot when midway between two points as it does if one is very close and the other quite distant. Key takeaway: if you set up midway, you can transfer elevation accurately with a laser that is out of true.

[@SkillBuilder]

That is brilliant John I will read that a couple more times to make sure I have it in my head then I will make an ammended video. Thank you for going to the trouble of explaining it so clearly.

[@johnwetzel5248]

@@SkillBuilder Thanks! I did forget one suggestion I should have made: Get the longest hallway in the building (or find a bigger building) and check the laser midway between two points that are 30 or 40 feet apart. Then, when you set up near one of your marks or tapes, you can really see the error at the distant mark and measure it well. Then, knowing the distance (15 to 20 feet each direction for the midway measurement) you can get the error at whatever distance (30' or 40' say?), and compare that to the XXmm spec per YY meters, to know exactly if it meets specifications.

[@fractalofgod6324]

Thank you John, I'm gunna read that ten times for it to sink in. 🙏👍

[@gallowsongs]

So if I understand it right you're in measuring pitch , rather than roll. Because the laser can be off in two axis. In your initial measurement, when you are half way, you are actually at the bottom of a T with ends of the horizontal bar being the tape/rods. When you set up next to one rod, you are setting up the instrument perpendicular to the first reading from there bottom of the T. But you might be in a situation where the pitch and roll are present in equal amounts, and you believe you have a clear reading, but the errors just cancelled each other. With a 360 later it's a lot simpler, but you could fix it by having a third tape/rod near the bottom of the T and checking all rods from every position. How I understood that right.

[@johnwetzel5248]

@@gallowsongs I don't completely understand everything you said, but I think I can answer your question because I do think I understand what you mean by "pitch" and "roll". "Pitch" in this case refers to raising or lowering the nose of an aircraft, whereas "Roll" refers to raising one wing and lowering the other. So, to understand completely what is going on, imagine that you have a perfectly plumb pole or pipe, and that you have attached to that a flashlight, and the beam of that flashlight points in an exactly horizontal direction. That is, the flashlight beam points towards the horizon, and relates to the plumb pole exactly 90 degrees angle. Now imagine that you replace the flashlight with a laser light that projects a tiny precise dot, but still exactly perpendicular to the pole, which still points towards the center of the earth's gravity (that is what "plumb" means). Now, you CAN think of that direction the light is pointing as "pitch". Pointing that laser beam "uphill" could be regarded as "changing the pitch". But, with a laser level, there are not an infinity of separate lasers pointing at 90 degrees. Instead, if you rotate the laser pointer and its laser beam around the plumb pole, 90 degrees to the right, you are now dealing with "roll" (if I understand correctly your use of terms). The key thing to understand here is this: If the pole or post or rod the laser is mounted on is perfectly plumb, and the laser is rotated very quickly, you will not see lots of laser dots, you will see a "line". If the pole is plumb and the laser is horizontal, the laser line will represent a "plane" (not an aircraft, but a geometric plane). If the pole is plumb, but the laser is pointing downhill or uphill, the laser line will represent a cone (actually, the part of the cone that intersects whatever wall you are looking at to see the laser line). In the first example, the rotation axis is plumb, and the laser is level, and the resulting figure is a level plane. In the second example, the rotation axis is plumb, but the laser IS NOT level. The resulting figure is a cone. I think the question you meant to ask is: "what happens if the level is 90 degrees (perpendicular) to the axis of rotation, but the axis of rotation is not plumb?". If that were the case, you would have a plane surface that might be "level" in the forward to back direction (what you call pitch) but off level in the side to side direction (your term "roll"). If that is a correct rendering of your question, you are also asking me "So John, how do you account for the possibility that the axis of rotation is not plumb, which would cause problems if everything else was good?". And, my answer would be "Wolfgang, you are correct, to find and correct that, we need to do the procedure twice". To account for this possibility (which is VERY rare) you would check the level exactly as I have described, but you would note the orientation of the physical laser device. This is hard to explain. If you have a car, or a camera, or a gun, or an arrow, there is an obvious "direction" that you can understand that the device "naturally points at". The barrel of a gun or the nose of an aircraft could be said to "point" in some direction. You could then call that arbitrary direction "Straight ahead" or "12 o'clock on a clock face". But your laser level has no "direction" that it "points at". So if your laser is shaped like a box, you would have to pick one face of the box and call that "straight ahead" or "12 o'clock. To check for the "roll" problem you mentioned, you would simply repeat the entire checking process, after turning the laser level so that it points "to the right 90 degrees" or "to 3:00 O'clock on the clock face". In other words, you perform my suggested checks/adjustments twice,, with laser pointed 90 degrees different the second time. Lets say you performed the level check as I explained it earlier, and you used the longest hallway you could find indoors to make it both easy and accurate. A long hallway makes for a very accurate measurement and correction of error, and inside makes the laser line easy to see. So, you would perform the check just as I had originally described, but you would note something about the laser that would allow you to define a "pointing direction". My laser is shaped like a tiny bus, with the two short sides of the bus being the "front and back" of the bus, and the two long sides being the "side" of the bus. So, if I was checking to make sure my level was good both in pitch and roll (to use your terms) I would first point the "front and back of the bus up and down the hallway, and do the whole check procedure. I would then repeat the entire procedure with the "sides" of the bus" pointing (oriented facing) the long hallway. Once your laser level tests level in both directions, you will have accounted for all possible sources of error. BUT, I must say, because of the way laser levels are designed, the "roll" error (rotation axis not plumb) is VERY unlikely to occur. On the other hand, the pitch error (laser not perpendicular to rotation axis) happens a lot. So, doing the check process I originally described is going to eliminate most possible error. Repeating the whole process with the laser level (the physical device itself) "pointing" 90 degrees right (or left) of where it pointed during your first check, that will eliminate all possible error sources. Why is this second type of error so rare? Gravity is used to make sure that the axis of rotation is perfectly plumb. Imagine that the axle (axis of rotation) is freely hanging from a support, and gravity makes it perfectly plumb. If I set up my level, and I tap it, I will see the laser lines on the walls around me "rock" up and down as the free hanging axle swings under its support. There are just not many ways this system can go wrong, its too simple and basic. But, rare is not impossible. If I left my laser outside for a couple of years, rain could get in, and rust the parts so that the axle could no longer hang freely straight down. In that case, I wouldn't need to do the above procedure to detect that. I would just turn the laser on, wait till the line stabilized, and gently tap the laser. If the laser line rocks gently up and down, it is working correctly. You are seeing the swinging pendulum that is the axle represented by the laser line moving on the wall. If it "shivers", then the axle no longer hangs straight down, but instead points "almost straight down" and does not want to move. At that point, you consign your laser level to the dustbin of history. I will finish by saying this: From my experience, the "roll" type error, which amounts to the axle not being able to "hang" exactly in line with the earth's gravity, is so rare I wouldn't bother to check twice with two different orientations 90 degrees apart. If your device did "freeze" this way, it would be immediately apparent in the odd behavior of the laser. When an axle does get stuck, it will usually give you a laser line on the wall that is so "off" you know it as soon as you see it.

[@fiddleronthebike]

the right way to check... only one small mistake: at the and you said the error is about one mm because you have to double the .5mm we saw (if I got you right...); in fact it's the opposite: because that .5mm we saw is the result of out and back of the laser line, the actual error is only .25mm/10ft. But that doesn't matter, it is very good

[@SkillBuilder]

I will have to think about that. You may be right

[@whitefields5595]

Roger, good vid. I had a cheapo laser level where part of the pivot bearing (a universal joint) fractured. Maybe I over-tightened the lock, who knows. This threw it out, but only when in one quadrant ! So yes check regularly. Clearly these are quick and easy for the pros, but for us casual types I’ve gone back to a water tube level as featured in your other vid. Cheap cheerful and foolproof. I think if I was building a long structure over 10m I would always do a double-check with a water level. Not too good on the verticals though, keep getting wet.😂

[@edgarhume8184]

Mark center of laser line, not one edge. Reason being that the line expands both up and down over distance, but eyeballing the center allows you to stick with the limits of the laser accuracy.

[@oakleybraylen7093]

i guess Im kinda off topic but does anyone know of a good website to watch newly released tv shows online ?

[@gatoborracho4572]

@@oakleybraylen7093 g t f out of here !

[@barryward1365]

Great video Roger, very insightful.

[@andyhello23]

Nice guide, have no seen your vids in a while. Good easy guide for most people to follow. Just shows you how un-level that floor you were working on is. You lifted that level quite alot. Its amazing how clear green is compared to red lasers. How the human eye can see green light far easier. Shame you pay a price extra for green, but if you can buy a green laser rather then a red one, so much more easier to see overall.

[@SkillBuilder]

andyhello Where have you been? We need you.

[@thepotterer3726]

Sometimes the MK1 eyeball is best, I was at the far end of a large garden, building raised timber beds into an existing paved area that sloped away from the building - with 'volunteers'. My Guvnor was at the far end of the site doing the groundwork for another paved area, something didn't seem right but I was fully occupied with making sure the 'volunteers' didn't lose a finger with a saw or take someones eye out with a drill.............and get the beds built. Come smoko, I laid a 4ft Stabila on the compacted Type 1 and it was falling towards the building..............the heights had been set using a Leica that had just come back from calibration!

[@SkillBuilder]

Yes you are right to trust your eye. I am still not trusting when I use a laser level so I still just check the line with my bubble.

[@falsealarmno]

Good advice. Thank you.

[@ChunkyMonkaayyy]

Thanks! Very practical advice.

[@andrewferguson8032]

Finally someone explained this in a way I can understand. Thank you!

[@rajaajk7665]

Good demonstration Roger thanks.

[@jimmcdonald6465]

Really helpful Roger, Thank you so much.

[@ningis21]

Nice quick check...Cheers. In your case the laser was rising slightly to the right....if you had left the tripod in the original position ( to remove any set up errors) and just moved the actual laser through 90 degrees to shine on the right hand (high side) wall...would it have shown the error as now the laser would be showing the lower side of its line to the left, as it did originally and would now show the true discepancy between low and high readings? (Basically.. low on left high on right....turn laser to right..90 degrees...putting the low laser point under your original high point on the right). A friend of mine used his laser on a tripod, and it took him quite a while to discover that the swivel base had seized, so instead of rotating the laser on a level plane...he was actually unscrewing it from the tripod very slowly every time he turned it to the left...elevating the level just a hair every time.

[@SkillBuilder]

Ah yes my head hurts now. You are right, that would have been a better way.

[@bestbuilder1st]

That is assuming the 90-degree rotation doesn't have any discrepancy in the plate it is rotating on? A very slight change in the rotating plate would exaggerate the "change?" or am I way off with my own assumption? I have had to adjust my camera when doing this because the angle is slightly different. The laser would adjust for level but wouldn't there be a difference in height?

[@fiddleronthebike]

no, not necessarily - depending on what is the reason for the discrepancy your method may work or may not; Rogers method is better because it shows any error in any case!

[@SkillBuilder]

@@fiddleronthebike I like your channel. Nothing I enjoy more than being out on my bike. I have done the Etape a few times and countless other events. I love the mountains of Mallorca. I am going to binge watch them now.

[@fiddleronthebike]

@@SkillBuilder wow, you are a cyclist too, that's great! Sadly I did not ride my bike for some time due to an serious illness in my family which stole much of my time - and therefor no videos since than... but I hope to be back on the bike in 2020. Love the mountains of Mallorca too, and the Alps, it's wonderful to ride there. And I like working with wood and in my house as well (though it is not my profession as yours...). I love your channel too! Keep up the good work!!!

[@tilerman]

Thanks Roger. I did notice that my laser level was not level when i tiled a large area and when 4 walls joined up the tiling was out by 6mm! Bit of fiddling and i lost it but not good. When im tiling long walls still use my old water level and set a datum with a chalk line. No mistakes with that method. Cheers mate.

[@SkillBuilder]

Big fan of the water level

[@tilerman]

@@SkillBuilder You should do a video! Had mine donkeys years. Man that taught me had it for years and gave it to me when he packed in. Actually made of brass and very niceley made. Few leaks in the hose and a bit of duct tape here and there but still works. Mind you, whats to go wrong! Cheers again.

[@SkillBuilder]

@@tilerman We have a video coming out. That brass one was a Holland I believe. Very nice, I would buy one, mine is plastic.

[@joeframer9642]

Nice job roger, love the channel 👍....

[@SkillBuilder]

Thanks Joe . Doing an American hook up next week

[@g1mpster]

Slight correction: a level that isn’t level is WORSE than useless, it’s a liability. When I was building my pole barn, I started with the site prep by using an old laser level that I assumed was still calibrated. After the poles were set into the footings, I was striking a level reference line on all the poles so I could measure up from that for everything else and I decided to double-check the laser level by setting up a water level. It’s a 36x60 foot shop so I ran the water level from corner to corner (approx. 70ft). I set the laser level up in the center and adjusted the water level to match but was seeing several inches of discrepancy from end to end. So I did another test like yours, strike the line where the laser is hitting and then rotated the tripod 180 degrees and marked the line again. Over 70ft the level was off by almost 5”. Luckily there was enough extra on the poles that I didn’t have to make the whole building shorter, but I did have to spend a bunch extra on gravel to fill in the low corner before pouring the concrete slab. Bad levels will cost you money (on top of needing to buy a replacement that’s calibrated correctly). I always remember this when I think about how expensive tools can be. Buy once, cry once.

[@mobeydick37]

"Slight correction: a level that isn’t level is WORSE than useless, it’s a liability." Wrong, you should ALWAYS, ALWAYS, ALWAYS, check like you did when using any level. You can use a level that is out of level by knowing it not accurate and dividing/splitting the difference and checking again like you should do regardless.

[@damod4416]

Whoever commented about the bosch accuracy . I did quite a bit of research before buying my GLL 80P . At the time it was more accurate even than stabilas version(+/- 0.3mm /M) , at a tolerance of +/- 0.2mm over 1M . The only thing better at the time meant spending £1k on a +/- 0.1mm rotary , with the Bosch £280 it was a no brainer and 6yrs on it's still excellent. Just saying👍

[@SkillBuilder]

Thanks this is just the kind of user comment we need. People can learn a lot from this experience.

[@GarypatrickGarypatrick]

You should work with middle off beam as the beam differs in thickness with distance

[@remus100776]

and that sir is the correct way to work on a laser beam!

[@anas7hamed]

Hey, what do you mean by “with middle off beam”?

[@RyanBissell]

@@anas7hamed He meant middle of the beam (rather than the bottom edge, as done in this video.) His point was that lasers spread with distance, so the far end of the room will have a wider beam cast than the closer end. So if you place the black tape's top edge to coincide with the center of the beam, you avoid that effect.

[@myshinobi1987]

According to SkillBuilder, the Bosch Laser HQ told him to work on the lasers edge. Go figure.

[@Patrick-857]

@@myshinobi1987 Manufacturers don't always understand how to use the tools they make.

[@dumdiversaspapalbull1452]

Very useful

[@JohnDuffell]

nice method, make sure to put the level close to the one tape and far from the other, and then vice versa, just to make sure the error is maximised. But even then it would be hard to find a big enough room to get a proper measurement indoors. Another way, I thought you were just going to put in one corner and mark the two adjacent corners, then move it to the opposite corner and line up with one of the marks. The difference between the two other mark and the laser would be doubled up so you'd be checking over twice the diagonal of the room. With only a 3m by 4m room you'd end up with the accuracy over 10m which would be very useful information.

[@SkillBuilder]

Good observations. The location was not ideal on this demonstration but outdoors it was a lost cause. I would tend to do it outdoors in the evening to have a better chance . Also I think I would mark out some lines and go back to the same spot for regular checking.

[@Maniwasaki]

Great information. Thank you for sharing sir!

[@trevorhayes1079]

Thanks for that

[@stanislavvovk6674]

Great and simple method, the only thing I would do is mark on the middle of the line, not on the edge, the thickness of the line can change depending on the distance from level.

[@SkillBuilder]

Good point well made. This tip was given to me when I visited the Bosch laser HQ. They said work to one side

[@anas7hamed]

Skill Builder can you explain this in a video please?

[@myshinobi1987]

@@SkillBuilder it would be great to get a video explaining this point and why this is the case. I just bought one of these and I'd love to be able to use it the right way from the get go.

[@julianvidal]

You could use a hose water level to check that too, but the tape method is easier.

[@SkillBuilder]

We have one of those coming up next week. Great kit, no batteries.

[@MrJFoster1984]

Best level in the world, 100% accurate and can go around corners. Use some food dye in the water to make it easier to use. 👍

[@SkillBuilder]

@@MrJFoster1984 Food dye? Marmite?

[@MrJFoster1984]

@@SkillBuilder No the kind you use to change the colour of cake icing, Ask the missus she will know mate

[@mickfromaustralia1762]

How do you check the vertical ????

[@nforester]

Always take middle of the beam! Bottom of the beam changes by distance

[@SkillBuilder]

I am going by the instruction issued by the laser manufacturer. They say top or bottom of the beam but it won't be that far out on a distance of 3 metres so either is fine.

[@Patrick-857]

I always go middle of the beam. I don't care if its against the manufacturers recommendations, manufacturers don't always understand how the tool gets used in the real world. Centre of the beam is always going to be the same line if your machine is reading level, no matter how wide the beam gets.

[@HectorPerez-tb8hn]

New subscriber here !! great video !! thanks

[@SkillBuilder]

Thanks for the sub! Welcome to our channel. We have over 500 videos, use the search bar on the home page to access subjects that interest you most.

[@HectorPerez-tb8hn]

@@SkillBuilder Thanks

[@alexanderchuyko4889]

It`s a nice tutorial. However it`s a bit unclear how to start this. Did you mark first spot in front of the laser level or you have found the last beam reach from the right than stick two opposite beam side from right to the left, please? One more question is how to check vertical accuracy in this case? Thank you

[@SkillBuilder]

If it is level it will be plumb because it all works on the same pendulum. Just mark on the end of the line then turn the level and mark the other point and see how it lines up. I think you need to try it to understand

[@Do_not_assume]

As your laser is on a tripod, if the tripod/floor is crooked then wouldn't you get an crooked laser line?

[@SkillBuilder]

it is self levelling

[@Do_not_assume]

@@SkillBuilder I don't understand. Does it have water inside that makes it self level?

[@mattk6827]

@@Do_not_assume A bit late but I believe they use magnets at the ends inside. The pendulum arm for say to the horizontal line is running vertical inside the device and inside below the end of that pendulum are magnets attracting to help stabilize. They have a tolerance, most laser levels now are 3-4 degrees that you can be out of level. If the unit is beyond that the line will blink, it usually chirps an alarm to let you know the unit isn't level enough to self level. A slightly crooked floor, tripod or anything else won't matter. Once the unit stops setting off alarms it determines the self leveling can take control and it'll work to find level. In the demonstration here, level was marked with both ends using the tape to mark where the level said 'level' was. Then it was moved. Only sighted or adjusted to be 'level' at one tape mark. Now if the tool is in fact level (what's being diagnosed) then it should automatically be level at the other end, at the other tape mark. If it isn't then it's revealing some sort of deviation. Sort of like checking a square box for level across the diagonal corners, if it's level diagonally from one corner to the opposing corner, then level again from the other two corners like an imaginary X across the box, the entire thing should be level 360 degrees around. Whatever that 'box' may be, band joists, beams, deck, top plate of walls or whatever. A number of them can also be manually locked and in that case they can be tilted and the self level no longer tries to operate. Then it just gives a static line that can be tilted on a tripod for angles like stair railings. But then it's not trying to 'level' anything and it's only meant to be a straight edge.

[@bobadkins2838]

If time is at a premium, just use a 4' spirit level to check your laser. Better than nothing, and spirit level accuracy can be checked in 5 seconds. Best and most accurate way of all to verify is a water level, but that's time consuming.

[@timmargereson332]

Hi Roger, I use the dewalt dce089 green 3 line laser & to check mine I use 2 metal plasterboard poles. I set them as far apart as possible (approx 10m) & set the level on one pole with battery at the back and mark the poles - then move the laser to far pole and set the lines with battery at the front & this shows any discrepancy in not just the pendulum but the mounting as well. By the way, you looked really good on Strictly last night with Luba 😂😂😂

[@SkillBuilder]

Tim. Poles apart! That is great advice. As for Strictly, I have never watched it. Anything with a studio audience mindlessly clapping along to the music has to be placed in the same category as The Billy Cotton Band Show, The Black and White Minstrel Show and all those other naff productions that have blighted Saturday evening television for years.

[@timmargereson332]

@@SkillBuilder 😂😂 you do make me laugh - proper grumpy old man 😂😂, mind you do have more than a passing resemblance to James Cracknell 😂😂😂

[@SkillBuilder]

@@timmargereson332 Good stuff Tim. Truth is that even when I was young I was grumpy. I ran a mile from all that middle of the road variety type stuff. In those days there were just two channels and the t.v companies thought their audience of 18 million was an approval rating whereas, in truth, it was a captive audience with nothing else to do. Now we have such a choice of viewing there is absolutely no excuse for watching Strictly. If I caught any of my family watching it I would pull the fuse. What we call in the trade a safe isolation intended to protect the occupants from harm.

[@ptremble9477]

Another great video SB, I guess another way is to leave the tripod in place and just to rotate the laser 90 deg or so, this way you only need a single peice of tape also?

[@SkillBuilder]

I am not sure how that would work but I will try it in our laser showdown.

[@ptremble9477]

@@SkillBuilder (in my head at least this makes sense so bear with...) fire the laser at the wall, tape one side of the horizontal beam (LHS for example), then rotate the laser on the tripod CCW so that RHS of the cross now sits on the tape (or above or below if it's not level!)...looking forward to the showdown, I've been looking at the Magnusson IM0301 from Screwfix, seems like a really good value laser for DIY'ers but not much in the way of reviews I can find.

[@narindershergill3105]

Hi I find the green laser line is thicker than red line?

[@plummetplum]

Roger, once I've got my level is it good practice to lock it then work from that, for example if I was tiling?

[@rabahrrrrabahrrr6817]

What is the price of this please reply from you please

[@debandmike3380]

ha, all the precaution of protecting the pendulum and then he kicks the stand. bosch recommends marking the center of the line, not the bottom, due to projection thicknesses.

[@BettySwollocks13]

send mine for calibration along with any torque wrenches every 12 months.

[@alexmassey4708]

Where do you get them done?

[@BettySwollocks13]

@@alexmassey4708 Hi Alex, we use a company called Zenith.

[@petemclinc]

If the level is not reading level to begin with, then your tape will be off and not level. Without comparing to some type of standard that is known to be level all that you are doing is checking for repeatability and not level.

[@SkillBuilder]

Maybe you just need to think about this a little more. If the level is not level and you move it to the other end and line it up with the tape it won't touch the starting line if it isn't level. If you can't understand it the best thing is to try it and you will see how it works.

[@thedalillama]

Funny, I was about to validate my level with a more complicated solution when it dawned on me to check KZbin to learn from experience. This is easy. I'm invested in my solution to the tune of $12. So, I may progress with it. I will mark out the height of 4 corners of a rectangular plane (in my largest room) using water in a clear tube and compare my laser level to those marks. Going forward, I think I can minimize error by casting the laser from the center of the room rather than from a corner where the laser is out of the way.

[@randomtask9029]

Just test it with the classic water in a tube method. 100% accurate.

[@SuperEddietv]

Atmospheric pressure across the room may be different. ;)

[@randomtask9029]

Eddie Adventure Yes. And water density if temperature is different.

[@covcarpenter9158]

There isnt always a lock on laser levels. And can you put a link to that tripod in the description ??

[@dougthebuilder1]

I just picked a similar tripod up for mine at the local charity shop for £15, keep your eyes out, there's always loads at car boot sales and second hand markets for cheap

[@covcarpenter9158]

Yeah but my prob with most of them and the dewalt and bosch ones is there not really building site quality. That tripod he has there looks beefy lol

[@dougthebuilder1]

Well you just have to look after it then, some of the old camera tripods are pretty hefty to be fair

[@covcarpenter9158]

I tried to modify a tripod that hold a dump level but it never really worked lol ill find one soon i suppose. What laser have you got then iv got the 360 dewalt with the 3 beams

[@DPJOINERY]

Yeah i were gonna say the same, my PLS doesn't have a locking device, wonder why?

[@DangleFilbert]

My Dewalt Cross line pendulum laser level has no lock function. You should always use the center of the laser line as your reference. I set up calibration marks with a water level in my garage about 7 meters apart and check my level against that.

[@SkillBuilder]

That is a good idea. Bosch say to use one edge of the line but the middle will do.

[@DangleFilbert]

@@SkillBuilder Now that's interesting - Just checked to see where I got the information about marking the laser line & Dewalt's manual for my laser does state mark the middle of the line, I wonder if that instruction is model/manufacturer specific? Wrongly assumed it was for all. Live & learn!

[@SkillBuilder]

@@DangleFilbert I don't suppose it matters that much, provided the marks are on the same bit,, but maybe the line thickens on the brighter setting.

[@isyt1]

I believe your test is simply showing the consistency of the laser level. Let’s say it was 5mm out initially then you’re simply showing that it’s still at least 5mm out from a different position and distance. Surely you should still verify the initial measurement with a spirit level, or ideally a water level.

[@SkillBuilder]

No because it is taking the line from the other end you will see a discrepancy.

[@Twobirdsbreakingfree]

​@@SkillBuilderisyt1 is correct. This test does not verify that the laser is level, but that it is consistent. It only proves that the laser will give a consistent line independent of its position in the room, but does not prove that the line is level.

[@owenb1t5014]

Don’t think the Dewalt laser levels have a lock function, my one doesn’t anyways.

[@superchip010368]

My dewalt level does NOT have a lock

[@remus100776]

some of them don't have a lock.

[@mighty_peach2760]

Pls doesn't

[@remus100776]

@@mighty_peach2760 not my native language....but thanks for help ;)

[@darland3821]

@@remus100776 you were correct, he wasn't.

[@Mentorcase]

I was using a dumpy level and I couldn't get it to read properly so I complained to the boss and he thought I was just whinging, later one of the apprentices came over and narced on the other apprentice, seems it had a rather nasty fall while the fool was trying to fix it to the tripod but dropped it and didn't think it was worth mentioning.

[@martin1977uk]

Great vid Roger but just a query could you have kept the laser level in the same place, mark as far left on the line with tape the swivel the laser level so that the far right of the line meets the tape on the wall and it should just touch the tape as before? Because the floor could be running up or down in another position.

[@SkillBuilder]

It is self levelling and provided you line up on the mark it will be correct.

[@martin1977uk]

@@SkillBuilder yes but if the floor in another position is running up or down for any reason it will give you a false reading surely?

[@SkillBuilder]

@@martin1977uk That is not the case. The laser self levels so lining it up with the second point should set it level with the first point. If it doesn't it has nothing to do with the floor, it is the level.

[@tttvn123]

When you change the machine angle, for ex from 0 degree to 1 degree, will the beam change angle or loose accuracy?

[@damod4416]

Most decent self leveling models will still perform up to about 4°

[@josephmalinowski6817]

I did find that very useful thank you I've been looking at the Bosch laser levels lately and I was told to go with the green over the red just because you can see the green better outside and my only secondary question is I noticed there's a big price range in laser levels is it better to purchase the very expensive or is it okay to get the middle grade laser level not going to be using a lot more or less to check the level of tile or molding base molding trim that's about it play Metallica comment resist you let me know I appreciate it thank you

[@NicolaiNNielsen]

Please notice that this test is not 100% accurate. I agree that it is probably the best (and only way of testing) for most regular users, but there's a chance that your floor isn't level. In that case, when you move the laser 5-10 meters in another direction, the floor height has not equal to the one before, and that can also affect the position of the laser beam.

[@SkillBuilder]

Nicolai It makes no difference if the floor is out of level. You may need to think about this for a while but when you move it from say left to the right end you have to line it up on the mark you have made on the right. Then you can see if the level is running back to the left hand mark. The laser is self levelling or should be so if it is accurate you should see the laser hit that left hand pencil mark.

[@MrBarrytommy]

Ok red laser vs the green laser is it easier to see ?

[@MrBarrytommy]

@@Total-Solutions Thanks That's good info Might get me one of those Cheers

[@TheStevenWhiting]

The question is, is that laser out by half a mill or is the tripod not accurate as you're having to wind it up slowly, so the tripod might be out instead

[@SkillBuilder]

It shouldn't be the tripod. The line is re-set to tape so you get the story backwards.

[@TheStevenWhiting]

@@SkillBuilder I would only assume if the tripod wound up smoothly and not in steps.

[@kevinr3263]

Tripods are neither in or out. It's just something to set the laser on. You could do the same test by setting the laser on a pile dog shit

[@madmatt7109]

What about.. set a horizontal laser, make a line on the wall than turn laser to the right, make a edge of light around your line on the walland see a difference ?? And same turn to the left? You dont need to move a laser level from place a to place b.. you will se a difference in the level in same spot.. boom

[@SkillBuilder]

That is not the way that Bosch suggest in their handbook. They say to move the laser.

[@hughjarrse]

Wouldn't it be just as easy to leave the laser in place and check it with a water level?

[@jovosedlar3395]

Right. Water level doesnt lie and cost $7.

[@flaviokonti5522]

​@@jovosedlar3395 water level can trick you also if you dont know how to use it

[@jovosedlar3395]

@@flaviokonti5522 of course. Person needs to know how to use it. I agree.

[@taipei5479]

3:30”, the laser is lasering his eyes as well isnt it? guess thats ok, now his eyes are level :)

[@johnburgess7165]

I just got this Lazer. Amazon had a pretty good deal. Got the decent mount and the case. 148 quid.

[@dejavu6938]

2:06 I guess , now it's not on the level

[@eyecatcher1509]

I once had a team of wall tilers eager to earn easy money fully tiling a large rectangular hospital kitchen, using a newgadget, a laser level.They did three and half sides about 120m2 over the weekend ready for my measure up monday pm. I arrived to see them removing the whole lot because the tiles were heading for a1" line out. Never put your trust in some new invention.

[@mirahgirl01]

Weird there's even a scope of distance they allow to be out of level! Level is level... 5/16" of an inch out of level is not level!

[@johnswimcat]

If you want something really level over several metres use a water tube. Make sure there are no bubbles in it though! That sort of accuracy isn't necessary for most building projects though. With spirit levels, engineering levels are much more accurate than builders' levels

[@stakkerhmnd]

Excellent video. Really appreciated. What are the 'non-pendulum' laser levels like in terms of cost and accuracy? Any tips would be fantastic.

[@SkillBuilder]

I would never bother with a laser that needs the little bubble placing in the middle of the dot. It takes too long. That said there is less to go wrong and they are cheaper.

[@duaneross9271]

What if the floor is not level.

[@SkillBuilder]

Makes no difference. You are lining up on the laser line from end to end and back again.

[@warrenpressure]

The laser blinked when you took your second measurement meaning that it wasn’t level

[@SkillBuilder]

It was level. It just got kicked. The good thing about self levelling lasers is that they recover.

[@Patrick-857]

I own a Bosch like that. It is blinking because the battery is low. It will blink and beep if its out of level, and the blinking pattern is more constant.

[@RichieRich845]

Couldn't it be the floor level fault and not the laser?

[@SkillBuilder]

No. Read the comments below. The laser self levels so when it goes on a line it should meet the other one whichever way you do it. That is the whole idea of the laser level.

[@flt528]

SO..... what happens when it's not level????? Is there a calibration feature? Do you dump it in the landfill and buy more another one (that will also go to the landfill)? I'm reading some reviews of these things and it sounds like a lot of them aren't accurate, and a lot of them don't last long.

[@dario.nistri]

WOW! You've discovered the precision tolerance. You can read it on the package of every measuring and layout tools.

[@dsotm58]

Can't really see what you are achieving buy what you are doing there could be so many variables that could come into play or am i missing something?

[@SkillBuilder]

Yes you are missing something. This is how the manufacturers suggest you check your level to see if it needs to go back for callibration. If you watch the video on checking a spirit level you will see this is the same idea. Just turn the level around and ask the same question. The laser level is self levelling so, provided you have two marks on the wall you will be able to place the line on the marks to establish what the level says is level and then by moving it to the other mark and setting it up on the line at one end it should, if it is level, hit the other mark spot on. If it doesn't it shows the variation. You could go one step further and place the level midway lined up with a midway mark and that would show how much it is out at either end. In this case we would be talking about 1/4 mm at each end which is well within tolerance.

[@dsotm58]

@@SkillBuilder Thanks for putting me right i now fully understand (maybe get a new presenter ;0)

[@galland3496]

Surely if the floor is not level , then setting up is not true !

[@SkillBuilder]

It is a self levelling level. Provided you put the laser line on your line it will find the level of the other mark. If it doesn't it is wrong. I think we need to do some basic instructions on these levels.

[@kmclfc]

You on the Lemo roger

[@SkillBuilder]

yeah

[@myshinobi1987]

This logic is flawed. Unless the floor is absolutely level, then the laser level could rise or fall plus or minus a mm or two over 3 or 4 metres across the room. This means that the variance isn't necessarily related to the laser being inaccurate.

[@SkillBuilder]

Hi Paul You may say that it is flawed logic but if you just try and think a little more about this you will see why it is a method that most laser manufacturers recommend. The laser is self levelling and if you establish the two lines at either end of the wall and then move the laser to the second position you may then have to adjust the height of the laser so the laser is exactly on the pencil mark. This means that even if the floor were 300 mm higher or lower the laser would still start from the second position and run back to the first. If the laser is working properly the line from the second position will meet the first pencil mark. That is how you discover any discrepancy. The floor level is not a factor.

[@myshinobi1987]

@@SkillBuilder I see what you mean however, given that the laser changes width over distance, the position of the laser device would need to be the same distance from each piece of tape vice-versa when the tripod is moved. Marking the centre of the laser with each piece of tape and then simply rotating the device on the tripod would give a more accurate reading.

[@psyience3213]

Jeez guy you dont know you go to the middle of the line? The thickness of the line changes at distance, the center of that line is what should stay the same.

[@SkillBuilder]

Jeez Mathew over that distance it makes no difference at all. We are not building a piano. If we get withing 1 mm we are happy.

[@psyience3213]

@@SkillBuilder it's very simple if the walls are not the exact same distance away the bottom of the line will be at different heights, meaning even if the level is dead on balls it could show that it is off. It's lasers 101 you go to the center of the line. It's simply not how you do it. Wrong. Imprecise. Not to mention you can just turn the laser to check.

[@istokman1729]

Dewalt doesnt have a lock , and is no cheap type.

[@tomkelly8427]

True.

[@figjam5181]

No homes would be levelled less to within 0.5mm over 10 ft.

[@YeahNahMaybe947]

Using terms like "something like" , "around about" and "probably" in a tutorial is not good enough. If I instructed my apprentice carpenter using those terms then it is I who has failed to teach him correctly and the best I could ever expect form his work is it's probably, around about, something like good enough .

[@johnnolan5571]

Thanks for the video, I bought a bosch gll 3-80 cg checked the accuracy using this method and it was spot on over 11 metres, I'm just thinking if it is correct along one wall left to right would it be correct along the other wall front to back

[@eastcoastuk1120]

Check it with the water level.

[@chrissayers7076]

I use my water level thats setup in my workshop to check my laser level is in calibration, I'm now on my second laser level, my first cheap level went out of calibration, and cost me money. Edit: and don't skimp on your tripod, its false economy.

[@Duetmaster2]

I would have to agree: a water level is the way to go if you really want to know. It may take a little longer to set up but it's worth it.

[@juancornetto8243]

Top laser level tip : Most of the major manufacturers want to charge you an arm and a dick for a floor to ceiling rod to mount your laser level too. £70-£120!! And tripods get in the way, (as rog' demonstrates in this video :P) and don't go low or high enough. Use a drylining ceiling boarding prop that can be procured for as little as £15 instead with a small steel plate tie wrapped on for the magnetic bracket to stick to :)

[@adampilkington9855]

With over 20 years of experience calibrating laser I can say laser go out because they are knocked or dropped. Also his method is not right. Have the laser close to a wall and mark it then doing the laser to another wall over 10 meters from the laser and mark it. Then move the laser to the first mark and level to that height, turn the laser to the first mark and you will see any error. These laser suffer from convexing, concaving or cross tilting which will produce terrible errors using his method.

[@SkillBuilder]

Thanks Adam I am interested in your finding and will ammend the information with another video. It would help us if we can find somebody such as you to assist in the testing. All we are trying to do it establish a simple test that can show if a laser need calibrating.

[@madalinnicolae5594]

I got lost in your explanation, can you simplify ?

[@dannymurphy1779]

Roger if you have moved the laser level did you level up the floor aswell???

[@SkillBuilder]

You don't need to. Just line up the beam on the tape.

[@WizardofGOP]

Having the music on while you are talking is distracting.

[@SkillBuilder]

Yes listen to the music without all that talking

[@forzarider9295]

If your Level is not level then its NOT a Level lol

[@robinturner2300]

ForzaRider what do you call a boomerang that won't come back? A Stick! Same as a level that isn't level?

[@das250250]

Lets say the laser is out by 10mm per 5 m ,higher on the left hand side to exagerate the scenario. Lets assume a perfectly flat level floor for now. If we place the laser on thr lhs facing this test wall and mark both sides we get the reference lhs marking and the rhs mark ,which in reality is 10mm lower from lhs. Now we take this laser on the rhs of wall . Because the floor is perfectly level flat our laser is 10mm above the rhs tape. Now as per your suggestion we raise the level 10 mm to align perfectly with rhs tape and look to the lhs laser and tape. What we will see is a laser line exactly in line with the tape because the tapes are offset by the error of the laser of 10 mm. Therefore this method is completely incorrect to my thinking. The only way to test is by rotating the level on a flat and level surface block 90 degrees or better hang a sheet of translucent plastic off a ceiling in the middle A room weighted by pegs and some small weights . Flash the laser at a distance towards this plastic and mark ends or extremes, then take the level from the other side of the sheet and line up one side and measure the difference between marking and laser. This will give the true error.

[@das250250]

I will add that you can use round posts or a wide opening where you can mark from both sides of the space .this method is essentially what you do with a mechanical level which is to test itself against the mirrors image ...

[@MegaRiffraff]

👍🏻

[@9421samuel]

Not completely wrong but there are more accurate ways of checking accuracy of your level. Do some research before making videos.

[@SkillBuilder]

It is the way recommended by manufacturers and is good enough for the accuracy. Point me to your source material, I am interested to see the techiniques.

[@a.lavernefilan1888]

Watch KZbin video, 'Why Flat Earth Laser Tests are Misleading Nonsense' 'Mick West'. Let me know what you think. Do laser beams curve around the earth or curve off out into space or is Nick West a space cadet?

[@stephenl7882]

That , is not how to do it.

[@SkillBuilder]

It is according to the instructions

[@hameedhaji6759]

Nice advertisement

[@Chalky-t5c]

Absolute cobblers. The centre of the beam is your reference point, as the further the laser is from the wall the beam is hitting, the wider the beam is. Incidentally, never use the vertical beam unless the wall you are hitting is perfectly plumb, or you are 100% square to the wall. A great example of how the plumb line is generally useless on a laser, is to aim the verticle laser at something leaning at an angle to the wall, say a piece of ply or plasterboard, and position the laser at something obviously not 90 degrees to the board. Even the naked eye will see the beam is woefully out of plumb......now imagine that's your tiles or a wall unit.....oh dear.

[@iggifer]

The vertical line is far from useless. I wouldn’t use it as a plumb line but it’s an excellent replacement for a chalk/ink line. So long as you treat it as such, it’s fine.

[@Chalky-t5c]

Iggfer, quite right, that's what I do when I'm tiling a floor solo. Incidentally, the Bosch gsl range are great for tiling a floor, because the cradle they come with and the plumb bob dots make it easy to go mark to mark. My point was I would never use the plumb line of a laser for a plumb line on a wall, that's what my trusty four foot Stabila is for.

[@MisterDivineAdVenture]

Weeeeellllll - hmm. Obviously the floor can not only be not level, but not even. Liquid in a tube that is of adequate length (or more) will use the EARTH'S GRAVITY and air pressure to seek its level - and will therefore be more precise than the laser mechanism once the movement of the water column settles (takes several seconds.) So secure one end of a long tube nearly filled with water to the first point - the reference mark - then go do the same to every other end of the tube wherever you want to mark. You are measuring with the level of water in the tube that once secured at the first point, will always be precisely the same level at the other end. This is only dependent on the Earth's gravity and air pressure being the same at both points - which it always is - and not on some previous construction.

[@SkillBuilder]

We have a video on the water level. On the other point about the floor not being level that doesn't matter since the laser is self levelling. You just need the beam to be on the second mark you made when you move it. When someone says something is obvious it is often because they have limited their thought.

[@kingmiller1982]

Horrible explanation

[@fetoe4110]

not accurate,,, thanks

[@garethheathcote4988]

It's made by Bosch therefore I would be very suprised if it was bang on level 😂😂👍🙂