How To Properly Splice Dimensional Lumber For Maximum Strength(Rafters & Joists)

How to properly splice or join two pieces of dimensional lumber (2x4, 2x6, 2x8, 2x10, or 2x12) for maximum strength to create a much longer board for rafters and joists when longer pieces of lumber are unavailable or have to be special ordered. DIY carpentry and save. Scarf joint variant. Replacing termite damaged or rotten rafters and joists. Enjoy the video!
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[@ProjectFarm]

What a terrific splice technique! Looking forward to your next video!!

[@electronicsNmore]

Thank you very much!

[@jaimemendoza5163]

I agree! Thanks for the idea

[@dennis-s]

Sorry is ''terrific'' another word for ''bad job'' (don't look like that btw)? it's a foreign language it's kind of difficult with some meanings

[@davidfuller764]

Agreed. And dare I say… Elegant simplicity.

[@PrimeSuperboy]

@@dennis-s You're thinking of terrible. Terrific means a great job.

[@churumbel52]

A year later..... What a great technique . I did it and it worked so good....! Thank you very much....!

[@stevearttus8164]

When determining how long the joint should be, I've heard it should be 3X the width of the material. 2x4 = 10.5" 2x6 = 16.5" Etc.

[@A5hunter]

Awesome video, was lost on how to extend my board longer with what I have without buying longer boards. Definitely using this.

[@chesterroj3008]

Retired carpenter 40 years never seen this fantastic

[@herbjohnson3027]

I watched your video about a year ago and was very impressed with how well the cuts fit. I need to span 20', with a 10' center post, and was going to use LVL beams. But, since I will have a 6x6 post in the center, I could use double 2x10's with this type of splice, and they would sit over the 6x6. I wasn't comfortable with overlapping the 2x 10's and having one joint on each section not sitting on the center post beam. On a 10' span this should be very sturdy on a carport with a metal roof.

[@George-pg2ii]

Thanks for this video. Super clean, clear explanation on how to.

[@sapelesteve]

Now that is one hell of a strong wood joint! Nice work.... 👍👍😉😉

[@Deep_Divers]

Well explained. Thank you!

[@lectro88]

I think I will employ this technique on a boat stringer with 3/4" plywood. this splice will be laminated over with another layer and epoxied and fiberglassed , so the jointery will be staggered, and layered over.. rather than nails 1/4 wood dowels also epoxied, there are no nails or screws in my build, no place for water to enter. This is the best method for splicing I have found, locking itself in place, I can see the advantage to this method. Thank You.

[@grahamspencer903]

Thanks for the very clear video! I'm going to try it today.

[@chrisgriffiths2533]

I Lived in an Old House which had Wall Posts which were Spliced like this. So this Method has been around for 100 Years at Least. Impressive Wood Join Method.

[@natehufnagel1431]

Very helpful, thank you for sharing.

[@FirstSuiGeneris]

I was taught by my grandfather and dad back in the late 60s doing these type of splices.

[@NotWolf__]

I watched you spinner video and came here you are a legend 🔥🔥

[@samfarhand6997]

This man is a master craftsman.

[@calmmusicforsleep]

Great work and awesome technique! Thanks for nice sharing! Have a wonderful day!

[@electronicsNmore]

Thank you! You too!

[@nanoceramics2747]

Excllent! easy to follow and very usefull on many projects. Thank you!

[@darthbubba866]

Fascinating presentation, thank you! 👍

[@electronicsNmore]

Glad you enjoyed it!

[@Johnezo1]

Great splice, thank you for sharing

[@electronicsNmore]

Thanks for watching John!

[@harlemsar]

Thank your very much, i´m doing a wood ceiling in Colombia, we are not really big on timber construction (we like concrete and bricks), this splice will help me a lot.

[@hossenfeffer8383]

Really good demo, thank you!🇨🇦

[@electronicsNmore]

You're welcome!

[@alpha-male1959]

This is exactly what I was looking for Fantastic job Thanks

[@electronicsNmore]

Glad you found the video helpful!

[@cryptobyrd1147]

I tried it and it works great

[@danellenix2942]

Great tip and detailed video.

[@Bushman9]

This is a variation of the scarf joint common in timber framing. It would be a simpler than the scarf for the average layman to build correctly and therefore a great alternative.

[@texasRoofDoctor]

Genius. Thank you for sharing this.

[@electronicsNmore]

Glad it was helpful! Be sure to look over my extensive video playlists below for many other videos of interest to you, and most importantly take one minute to share a link to my channel with others. Thanks kzbin.infoplaylists

[@markirish7599]

Brilliant video

[@JFAM077]

Awesome super help thanks!

[@RafterSkills]

Good stuff!

[@rochiellebevans1783]

Wow, so cool; I'm from The Bahamas.

[@user-wg7dx7er8w]

Hi , the Japanese have been using this type of scarf joint for hundreds and hundreds of years, the main feature being that is in the centre of the scarf there is a pair of wedges driven in from other side to lock the scarf joint together, if this is done properly on a beam they’re quite often would put a Mortis and tan joint through it as well which will then lock it all together , I personally would not of joined a piece of 2 x 6 2 x 8 2 x 12 in this manner as there is not enough surface area on the 2 inch thickness, and definitely would not be in an area where there is load being transmitted, stay safe, don’t bridge that gap,

[@bombardier3qtrlbpsi]

Nice job 👍

[@kaackster]

that's really a great method

[@ededmonds8792]

WOW you got some 🌞 bro.TY

[@kbjerke]

Cool tip! Thanks!

[@electronicsNmore]

Thanks for watching Karl!

[@rayravshanov]

this guy rocks I was gonna replace my roof decking. I m gonna do that

[@DATDesign]

That's one awesome splice! I'm making some stairs for a garage loft, and the stringers are a tad over 16'. There was no way I was hauling 16' boards in my 5' box Tacoma. 12' is the longest I felt comfortable hauling, but this joint looks super strong and makes me feel better.

[@michaelbyrne8860]

Thanks well done!

[@mikepatchett9441]

Very strong Craftsman style joint. You can omit all the glue and fasteners, with a dowel at the center point. Hold the joint slightly over closed (lapping) hole saw through a scrap on the top of the left hand side, the right hand (lapper) , and into scrap supporting the (lapper) the dowel is now a (pin) trying to hold the joint over closed, preloaded resistance to deflection I would still glue up 2xanything. makes a beautiful joint in exposed raftering functional or not. Thank you for the cool video, and for triggering a fond old stream of thought.

[@nickmacaroni]

can you explain this further, link to a picture or something?

[@mikepatchett9441]

Skill Builder has a good video that shows the purpose of the pin tell me what you are trying to do with this joint, and I will try to help. I am not an engineer@@nickmacaroni

[@eddieco]

Great video. I actually have to do this and was wondering how.

[@DavidRexGlenn]

I love this channel

[@electronicsNmore]

Great to hear Dave!

[@kenl2861]

Awesome technique, thanks for that. I assume if you have any further strength concerns you can add a sister or two across maybe 2x that splice section

[@zaiks0105]

Thank you, Sir!

[@electronicsNmore]

You are welcome! Be sure to look over my extensive video playlists below for many other videos of interest to you, and most importantly take one minute to share a link to my channel with others. Thanks kzbin.infoplaylists

[@Quickened1]

That's a cool splice. I've never used that method, but it looks sound. The only other advice I'd give when doing this, is to make sure the carriage bolt heads are positioned on the side of the board where the crown is up if there is one, and there usually is. In fact one might consider engineering a specific crown on a board so long, depending on application. In your case, it's not needed because of the support of all the jack rafters. The last time I built a hip roof that size, I used LVL beams for the hips, but it was a free standing carport that needed additional support... I might also add a piece of glued and screwed, half inch plywood to each side of the splice, just for added shear strength, but I like your splice overall!

[@electronicsNmore]

Correct. Head of bolt crown up. The good thing is, the jack rafters lined up in the spliced area, which adds more support. Glad you liked the splice!

[@deosiewilson732]

Very good.....I have been looking at the best way to join some joists and this looks like a winner 🎉........

[@gussygoro2469]

That's really super

[@clearviz100]

A really clean finish, I would go one step further and recess the bolt (planning an exposed truss finish)

[@mthebone]

Great Video. Explained it really well. Muz AU

[@robertward553]

Nice, I like it.

[@codyabel4766]

concise!

[@Edmorbus]

Nice video

[@electronicsNmore]

Thank you Ed!

[@mrcryptozoic817]

Scarf joints have been used by timber framers for hundreds of years. You're right, they are the best. And even better, look up "locking scarf joint".

[@Brainchild69]

Very good to know!

[@electronicsNmore]

Glad you enjoyed the video! Thanks for watching

[@bjkcoronel]

Thank you for this video. 😊 though I would like to ask if this is also applicable to beams with direct weather exposure? Best to use galvanized bolts? The embedded bolt heads should also be sealed?

[@00Skyfox]

How well would it work to use truss plates on the sides instead of nails driven through?

[@GalenCop9]

Great video and demonstration! Thanks!!!

[@electronicsNmore]

Glad you enjoyed the video! Be sure to look over my extensive video playlists below for many other videos of interest to you, and most importantly take one minute to share a link to my channel with others. Thanks kzbin.infoplaylists

[@Digidoc316]

To insure the two boards are nested tightly, screw a block to the board faces just past the joint and put a clamp across the gap. This applies pressure to the glued surfaces insuring a tight bond.

[@SamFBM]

very good and simple too. i hate it when people overcomplicate stuff for no reason or to use as little fasteners possible make no sense in todays world where everything is available

[@electronicsNmore]

Glad you enjoyed the video Sam! Be sure to look over my extensive video playlists below for many other videos of interest to you, and most importantly take one minute to share a link to my channel with others. Thank you kzbin.infoplaylists

[@cirelefebure5485]

thank you

[@electronicsNmore]

You're welcome

[@waynehansen3349]

Saw this in Jamaica years ago

[@superdog1964]

Awesome splice! I am curious if this meets ANSI/BOCA code and if inspected by the friendly and pleasant local enforcement officer, would it pass?

[@52RedHouse]

Maybe as a hip, as long as the jack rafters are laid out properly and matching on each side of the hip. I've always been taught to upgrade to engineered lumber in that situation.

[@rochiellebevans1783]

Masterful. Will this work on my front rim joist for my new deck. I need to either splice the joist making it about 18 inches longer or make it shorter by digging a new footing and moving it in (shorter) by about 18 inches. Would appreciate any suggestions if you can understand my description of what i'm trying to do

[@alanrawson-wg8io]

I would be inclined to support the splice with a plywood plate on both sides that would be 1/2 again longer than the length of the splice.

[@edwardfaris8516]

It's called a scarf joint...pretty strong for sure...😉

[@executive]

if you want it really strong, use a wedged tabled splice joint

[@gregorybear7367]

That was pretty slick. Awesome! I'm needing to do a 24ft span on a elevated platform,using a 2 by 10. What would the measurement s be on that? Thank you

[@Shadowman444w]

Om doing the same next week on my workshop roof

[@tatersdomergue6463]

That's much simpler than other methods

[@sorrymrgoogle2601]

Man's splice is stronger than the rest of the board....

[@toddwheeler1526]

A warning to folks using this technique. It should only be used for non load bearing applications unless the joint is supported at the splice accordingly? Never exceed the span tables clearly outlined in the codes unless approved by an engineer or building department. Long fascias or barge rafters are a great application for this technique. It's a form of a " Scarf Joint " BE very careful.

[@MrLgmurphysr]

If a hip rafter gets overspanned, it isn't a hip rafter. I don't know anyone who would use this joint and not sister a six foot piece spanning the joint when not applied as a hip.

[@ThisIsToolman]

You are correct to caution. There is a tremendous potential for DIY naïveté to create a far less than adequate joint. However, I would have confidence in my own work. Use of the proper glue, clamping scheme, and a precisely crafted joint would be stronger than the wood. The span is a separate issue, glued or not. You don’t want to run amok the code.

[@D-proGram_Yousef]

​@@MrLgmurphysr 👍💯% my thoughts as well

[@moepow8160]

This is great. I wish you would have given measurements for different size boards, but what the heck? I'm only building a firewood shed. This I quick and easy. The only issue today is finding straight boards !

[@Remedio-ff2bx]

0 90⁰0000000pppppppppppp0pp⁰ⁿ

[@ntsftdjj]

You are a brilliant physicist, what did you want to become as a child?

[@nicoliderringer9990]

Do you know how to properly join 2 6x6 *(5 1/2 X 5 1/2)* barn poles together end to end if you needed to lengthen a pole?

[@_Ramen-Vac_]

Cool joint. . . always love a learning "New way" .. I do the V splice, takes more fastening... never glued em tho. At first i thought u were beveling the cut but you're plumb here, , , hurricane clip brackets and "buckets" too? Do you crown your boards? Lots of love for the greatest skill. We got to where we made games out of it all and threw up some showplaces.

[@_Ramen-Vac_]

oh bOLted too lol dam...

[@Whooooho]

This is good for single pitch roof too ? 24 ft 2x12

[@psidvicious]

It’s called a scarf joint. I’m not sure if that was mentioned, throughout the entire video.

[@johnkennett3265]

Wow! Talk about good timing, I have to make 22 foot joists in order to upgrade our Philippines built homes ability to stand up to Pacific Ocean Typhoon shooting gallery. Our front door faces Taiwan. High tide raises up under our floors twice a day. So both home Footings and the roof rafters must get special treatment. The typical galvanized joist hangers, Hurricane Strapping, strong wood glue together with your technic I am working on it right now.

[@ChimeraActual]

Interesting. A scarf joint on a plank on a boat generally mates the wide dimension at an 8/1 - 12/1 thickness to length ratio.

[@ErenYeagerOp]

Kicking experiment please

[@yeahitskimmel]

I'm sure it works but that doesn't mean I don't wanna see strength tests. Awesome trick to know

[@electronicsNmore]

In the future I may make another and put a load on it to compare to one that was uncut.

[@TIMOTHYEET69420]

Would this work on a tool handle

[@chrisalister2297]

I skipped parts of the video, so not sure if it was mentioned. Make sure both boards are crowned up once the whole piece is assembled.

[@b1zarre23]

If this is the only thing you have, I guess use it, but I would have put a length of plywood on both sides with construction adhesive and many structural screws.

[@electronicsNmore]

That will definitely add a lot more strength

[@whirving]

I assume this would also work for wall studs?

[@dingbingbong]

If your wood is somewhat green, you should tighten those bolts after a year or so.

[@electronicsNmore]

True, my wood was fairly dry

[@cmills1008]

He sounds like Billy crystal 😂

[@happyotto6436]

Cut must be at 90 degrees, sharp angle will split the wood like wedge under the load!

[@jeffreylonigro1382]

LOL...Framed a few in my day. That would be an exceptionally difficult joint to cut on a job site. I like how you switched from layout to poof: assembled joint. Gee, how long did that take? An hour?

[@electronicsNmore]

Cutting was fairly easy. I used a hand saw on the ends of the cuts, the small cuts that were angled. Then I did a pocket cut using the circular saw for the straight length. Once that was done I simply laid it on top of the other piece of wood, traced it and then cut it the same way. About 30 minutes

[@robertpelland5649]

You might want to look how splice joints are made in Japan by woodworkers.

[@jonathanb6911]

Guys, I need y'alls help with this. How do you use a table saw to initially cut these marks. I'd get a band saw blade or circular cut here, but not a table saw Thank you

[@rubygarcia1391]

Building our house the carpenters spliced the lumber that is thicker than that using that technic and a saw, no power tools. In 1990

[@owenparker6651]

I was wanting to use a shed roof on a small summer cottage I am planning but the planned width was 16' and that is the maximum length of boards I could get locally so I was resigning myself to do the traditional gable roof. Perhaps I could use a splicing method along these lines to make 20' rafters. I was looking into some sort of gusset plate methodology. Would you prefer splicing over using a metal plate? Would either pass code? Thanks for sharing this method!

[@electronicsNmore]

For a common rafter, you can probably just glue/nail as shown in the video, then take a strip of 3/4" plywood that's a little longer than the splice area and nail it over the splice area on both sides. That rafter will never come apart.

[@owenparker6651]

@@electronicsNmore That sounds even easier and that makes sense. However, given the price of plywood here on the east coast of Canada, the metal plates might be less expensive! 😒 Thanks!

[@user-fq9ip1tv5b]

Why would you ask this idiot if it will pass code? You have to be kidding...

[@heminessa]

Is there away to do for 2 by 2?

[@z4zuse]

It is a variant of the Scarf Joint

[@electronicsNmore]

Correct. Thanks for watching!

[@zaiks0105]

Post-experience 2nd comment ... 1. Dangerous when you are cutting it circular saw. Plunge saw is better but still dangerous 2. Drilling the long hole straight is NOT easy. If you use hand drill, it'll likely be tilted. You need to buy long drill bit which will go all over the directions. 3. Not economical - took a long time! I've done about 20 cuts to be used as plunks for temporary roof

[@terryharris3393]

This may be pretty but it wants to separate (slide apart) when loaded which places stress on the bolt which causes shear stress on the timber. Wood is not the strongest under shear. A proper scarf is only a little more complicated and when loaded places the scarf in compression, which is wood’s greatest strength. Your Bahama’s anecdote is interesting but hurricanes don’t load a roof with weight but a lifting force or shear force. In North America it is the snow load that will stress the roof and your ‘splice’ will be vastly inferior to a proper scarf. Your hip rafter is a load bearing member, isn’t it?

[@rdw3171]

I would be interested in seeing a photo or diagram of what you suggest here

[@Dimythios]

There are different methods as shown. This one is good for standard construction methods IF you have the time. However this is also overkill as this takes time to make while on a construction site. Never the less it is good that this type of splicing has been shown to newer diy'ers.

[@ruidadgmailcanada8508]

Never time to do it right, always time to do it twice. 🤡

[@faizullakhan1556]

Can this be used to splice two 2x4x8 to span 12 feet? I need to small storage loft in my shed. The span would 12'. The shelf on top of the loft will be 3 feet in width.

[@user-fq9ip1tv5b]

Yeah sure, why not. And then load up a few thousand pounds just for good luck. What could possibly go wrong? You people are idiots. If you had a sore foot, would you ask the janitor if it's OK?

[@spunas1]

Scab averse?

[@cera8105]

❤❤

[@JT-lq4yd]

Great tip! How long of a span can this splice cover?

[@electronicsNmore]

Ideally on a long span, especially for a floor joist, you'd have an area of support under the splice making it virtually indestructible.

[@tribalvibes1]

@@electronicsNmore Clever technique ~ I need to replace a bunch of rotted 2x8 deck joists 8' long with the replacement being around 5-6' and the remaining good joist around 2-3'. Is this joint strong enough and suitable for that type of application ? As a hip or rafter it is supported by other boards but this would be from the house wall to the rim. Only 8' span with ipe (heavy hardwood) decking. I'd like to make the splice in place without removing the decking! Even if I have to drill through and plug it in places to install the carriage bolts etc. Any thoughts? I could also put truss plates or plywood scabs across this spice but I'd like to not sister the joist so that it lines up in the original location under the decking. Thanks!

[@rayleemck]

Do you think this technique could be used on making a taller aframe roof

[@user-fq9ip1tv5b]

350 feet. Maybe 400.