How to plaster an outside wall

[@Bluejohn]

I dont understand all the negative comments about lack of speed. If im paying for a rendering job the price will have been agreed beforehand, so it wont matter how long it takes. The only important thing is that the job is done right. No one is ever going to remember how long the job took in years to come but if the job is poorly done it will always be obvious. Great video.

[@SamDaviesBuilder]

Thanks John, very true words, thankyou :)

[@elcidcampeador42]

I agree 💯

[@leecantillon926]

Should be working left to right

[@MarkRyan-y9p]

And he’s blocklayer not plasterer but the plastering is good

[@hennessy4314]

Any negativity should be ignored. youre doing gods work posting these videos and this information

[@SamDaviesBuilder]

Thanks, I really appreciate the comment and thanks for watching!

[@declanstaunton7661]

Tell you the truth I kinda admire your enthusiasm, I am a plasterer I'm 39 , my dad my all my uncles ware and are plasterers , I started going with my dad when was 11 , put up my first trowelful when was 13 , one mistake your makeing really , the blocks made nowadays aren't full of holes and rough as fk like I first seen , these walls should be studded, they look very non porus, as in very smooth , weather it's boundary walls of house I always scud ,2:1 sand cement no water proofing or plasticiser, then your base and finish ,this was okay 20 years ago but the way blocks have gone , you need to scud , just my oppinion as a real tradesman , but fair play to you , nice

[@SamDaviesBuilder]

I understand what you’re saying, our blocks are pretty coarse though. I’ve never seen anyone do skudding here in West Wales. Are you in Ireland as I’ve seen loads of people talk about skudding in comments when it’s work in Ireland 🇮🇪

[@GB_Reloading]

this help me loads with my garden project, thank you very much you've been a massive help 👍

[@SamDaviesBuilder]

No problem at all, thanks for watching 😃

[@robjb21]

Very nice, I usually like to rule off the scratch coat too, makes top coat easier, (for me) looks as if you got it nice and flat anyway, agree with you everyone does things differently in the trade. Great video.

[@SamDaviesBuilder]

Rob Benn Thankyou for the comment!

[@ashyclaret]

Helps with the key also if you rule off the scratch coat and leave it rough.Stops all the sagging you sometimes get from a smooth trowel scratch coat.

[@SamDaviesBuilder]

ash wednesday good tip that is!

[@ashyclaret]

@@SamDaviesBuilder Just spreading the knowledge.lol

[@davidhammonds621]

Lee Casper I agree 12.5 is ample. Also you should never let your scratch comb touch the brick or block behind as the whole idea to to not only create a key for the top coat but to give you even suction especially when on old bricks or walls consisting of all sorts. Good video though.

[@SamDaviesBuilder]

David Hammonds good point about the scratching. Thanks for the comment :)

[@graememaguire692]

Looked really good finish and interesting to hear others views. I agree everyone has different ways. I always work right to left when rendering or undercoat plastering and left to right when applying finish. I would say you are rendering the wall as using a sand n cement mortar. Not outside plastering. Great job and hope others learnt from you sharing your way of rendering a wall. 👍

[@SamDaviesBuilder]

graeme maguire thanks Graeme! Yea I love checking out the ways other people do things and their techniques

[@dillyhill2127]

I've always worked right to left when rendering so your working into the material and not away from it

[@ronniebiggs4026]

Very good and I like the no panic easy going attitude 👏🎥👍

[@SamDaviesBuilder]

Thanks 😄

[@VladimirS38]

Thank you for so understable and clear tutorial video! Great work!

[@SamDaviesBuilder]

VladimirS38 thankyou so much for your comment :)

[@bensharpe370]

Right to left if your a right hander only left to right when your skimming.

[@SamDaviesBuilder]

Ben Sharpe I’ll be honest I go either way, jobs always show up places where you have to do different things

[@ollielake7421]

I’ve heard that what is the reason for it?I work left to right no matter what I’m doing

[@bensharpe370]

@@ollielake7421 when your skimming your not trying to put loads on your pulling away from it all the time so if your a right hander you go left to right. When your floating you want to build up the gear on the wall so your always working into it, so you start on the right so your swinging into it all the time.

[@ollielake7421]

Ben Sharpe makes sense I’ll try it thanks for the quick reply

[@bensharpe370]

@Daniel Johnson good for you mate

[@Nofixedabode859]

Good finish m8, never known anyone to put thick scratch coat on and rule it though especially on good wall, not necessary but each to own also we go 3/1scratch and 4/1 topcoat but like I said very job 👍

[@SamDaviesBuilder]

mick skinner cheers Mick, appreciate the positive comment!

[@jerrymoore6583]

Great job Sam, very well explained, can't see why left to right or right to left makes difference? you can either do it or you can't!!

[@SamDaviesBuilder]

Jerry Moore thanks! No I never knew there was a direction to go!

[@mosesfrog802]

It depends really,if you are right handed you generally want to pull the material to your right ,away from yourself ,you will often hear a plasterer say ,I pulled that room in so much time, Pushing is harder than pulling ✌️🧐

[@KevinChurch-c4l]

At least he uses a hawk and trowel..most videos show taping knives being used....nice form sir!

[@SamDaviesBuilder]

Thanks 😃😃

[@Topchip23]

Good video mate , not 20 mins of bollox and product placement . Good job

[@SamDaviesBuilder]

laurence I appreciate the comment, thanks :)

[@StephenMolloy-le3cc]

Great video and no bs. I don't have the tool your using to rule off the wall. What's the best alternative thing to use. I just have a small area to do and want to keep cost down. Would a length of timber do the job for rule off??

[@SamDaviesBuilder]

Timber would be ok just make sure it’s straight. A 1200mm length timber would be best if it’s a small area

[@StephenMolloy-le3cc]

@@SamDaviesBuilder great stuff thanks for reply

[@newtondsouza6091]

best video so far

[@SamDaviesBuilder]

Thanks 😃😃

[@AyiviTV]

Very nice👍🏼 Please, for concrete wall plastering, how many square meters of surface area will a 50kg bag of cement cover on average (outside and inside)?

[@khanos73]

very useful video, thanks for sharing mate

[@SamDaviesBuilder]

Thanks :)

[@kevinsmith-dn1px]

You make it look so easy, a mate let me try it once..I think I did a good job of plastering the floor 😅

[@SamDaviesBuilder]

kevin smith thanks! I remember when I first did it, I was terrible!

[@declangreen9707]

Is it critical to do 2 coats? I'm going to do my concrete block planters in my garden, will I get away with 1 coat?

[@SamDaviesBuilder]

If the blockwork is pretty good you’ll be fine with one coat

[@MrCobbsalad]

a professional at work 👏 is the mix consistency similar to a bricklaying mix?

[@SamDaviesBuilder]

Thankyou 😃. Consistency would be a bit wetter than a bricklaying mix

[@brianmays4366]

Thank you this is absolutely brilliant, could you give an approximate time line for the job? I know you said that the weather will affect things but it does help with your calculation.

[@SamDaviesBuilder]

Thankyou! I’d say 3 hours in the summertime and 5 hours in the wintertime!

[@PeterPanQuails]

Plastering seems a very labour intensive process. I am glad that I like exposed brick wall. Maybe a half brick and half render is a good combination.

[@carlosjuarez7522]

Never go full stupid

[@ossilong]

May I ask how and if you seal the plaster down where the pavement stones are and how you fill the gap between the plaster and the stones once they are in their place again? thanks for the awesome tutorial man.

[@SamDaviesBuilder]

Thanks. You wouldn’t seal it as such. Water will always work it’s way down. You’d just cut the pavement stones to fit up to the wall and then brush kiln dried sand in the narrow gap

[@stormbytes]

Beautiful job 🎉 What is a plasticiser and how much do you add?😊

[@SamDaviesBuilder]

Thankyou 😃. A plasticiser basically adds air to the mix to make it workable - you won’t have a mix usable without some form of plasticiser. It depends on what brand plasticiser and how good quality your sand and cement is as to how much you’d add to a mix. Say for a standard mixer full you could put two capfuls of plasticiser in on the stuff I use.

[@stormbytes]

@@SamDaviesBuilder I'm in the US so trying to adapt this "recipe" to what we have available. I LOVE what you did. Have a wall that's been spalting for a decade! Do I want to look for any specific quality of portland cement / sand? Was gonna pick up whatever Home Depot has.

[@SamDaviesBuilder]

@@stormbytes it’s hard for me in the uk to know what brands of cement you have over there but try and buy a premium quality cement suitable for bricklaying/rendering. With the sand they do a plastering sand over here so see if there’s something like that in home depot, just make sure the sand isn’t too coarse. Here is a link to help you understand plasticiser: www.designingbuildings.co.uk/wiki/Plasticiser You may be able to measure your wall and input measurements on an online calculator to tell you the quantities you need. There’s loads of free online construction calculators Hope this helps!

[@SamDaviesBuilder]

@@epiphgd4302 it works but I wouldn’t recommend it. Proper plasticiser is cheap enough and ensures no issues

[@dillyhill2127]

Love the vids mate but being a right handed spread shouldn't you be starting at the opposite end?

[@SamDaviesBuilder]

Cheers! I’m not actually sure on that one, I’ve probably got into bad habits with which direction I should go 🤣

[@kevinlee5368]

That is brilliant 👍

[@SamDaviesBuilder]

Thanks Kevin 😄

[@jaroslavpirkl]

very precise and beautifull

[@SamDaviesBuilder]

Thanks! 😄😄

[@Jack.Doughnut]

Would this work with concrete fence panels? The rectangular slabs sort.

[@SamDaviesBuilder]

Sorry, it wouldn’t work in that situation

[@Jack.Doughnut]

​@@SamDaviesBuilder nice1 Sam

[@greenbean5333]

Nice job!

[@SamDaviesBuilder]

Thankyou 😀🙏

[@kakuzumoneylover3942]

Great Job man. Question; why did u use a sponge to wipe the wall after???

[@SamDaviesBuilder]

Thanks! I use a sponge to get any float lines out of the wall

[@Ben83597]

Please explain the plasticizer? Do you have a link to the product? How much did you use? Thanks.

[@SamDaviesBuilder]

Jan Nielsen the plasticiser is an air entrainer for the mix. It replaces the use of lime. You can’t use too much or there will be too much air in the mix. rover.ebay.co.uk/rover/0/0/99?loc=https%3A%2F%2Fwww.ebay.co.uk%2Fp%2F1406279262%3Fiid%3D293347555138 that’s the product I’m using

[@mrgrunt4038]

Also adding too much plastisiser will weaken the mortar. The use of plastisiser makes mortar more workable, easier to use and work with. You can use hydrated lime which is really good

[@sbravo831]

Great video. I want it to be a light grey do you have any pointers?

[@SamDaviesBuilder]

Thankyou. This render would dry a light grey after a few days. You can buy dyes to go in the mix but it’s not the easiest to get a consistent colour. You can also buy coloured bagged render which may be something to consider as you’ll get the exact colour you want then

[@Suplement240]

Gracias por todo my friend

[@SamDaviesBuilder]

No problem, thank you for watching and your comment

[@VizslaVlog]

Top job mate

[@SamDaviesBuilder]

VizslaVlog thanks 😄

[@ephorntube]

Nice job and thanks, I’ll try the right to left approached mentioned below as I’m a righty.

[@SamDaviesBuilder]

Pat Horn thanks :)

[@plummetplum]

Hi I have been asked to re-render an external wall as it's got cracks in it etc, but behind the wall is the ground/road/basement effectively below the water table. How should I approach it, I presume there's no proper drainage behind the wall. It's always going to be wet, should I just render as usual or try and waterproof it, but how? thanks.

[@SamDaviesBuilder]

Personally I would paint on a thin slurry of sbr + cement mixer together then do a very thin scratch (make sure the wall has had a good hack off/wash off first to get rid of any old render) Then do your top coat as normal. I wouldn’t use waterproofer just Feb. If you want to cover the cracks then you could press mesh into the scratch coat.

[@callumstewart86]

Would you leave a gap at the bottom to allow expansion and for moisture to seep out?

[@SamDaviesBuilder]

No need for that in my opinion

[@callumstewart86]

@@SamDaviesBuilder Great - thanks for your reply! Great videos too, thank you very much.

[@SamDaviesBuilder]

@@callumstewart86 Thanks :)

[@Ukman-england]

Yes put a drain there otherwise the garden will fill up with water and plaster will fall of wall

[@Brian18741]

Grey video, thabks! How deep did you score the scratch coat, all the way through to the block?

[@SamDaviesBuilder]

Brian18741 thanks! Not quite all the way through to the block, about 3-5mm into the scratch roughly.

[@antonceta1]

Excellent job thanks for the video it did help

[@SamDaviesBuilder]

Thanks!

[@deltajohnny]

Thank you very much for the very helpful video and it came out great!!! 👏👏👏😉😉😉

[@SamDaviesBuilder]

Thanks! Nice to see people doing their own jobs from it :)

[@redsreds6598]

Ok mate, top video quick question what said is best to use? I am a diyer & I want to render my block wall which has been bare for years. Do I put a waterproofer in scratch coat & top & how long do I need to leave scratch before I top coat it. Do I just spray scratch down with water to stop suction & what ratio mix do I use. Sorry for all the questions but I have no experience 🙈 I try my best but someone as good as you with a little advice I am sure I can get it to a good standard no where near your wall got no chance that's a cracking job 100%

[@SamDaviesBuilder]

bcfc red army you can use building sand, there is also plastering sand but either is fine. Make sure you pressure wash the wall off first if it’s been bare for a while to get anything like moss off it. In my experience I only use waterproofer if it’s a wall that is dry on the back of it such as a house wall. If it’s a garden wall then I’d just use plasticiser (Feb) on both coats. But that’s just my way of doing it. Plasticiser on scratch cost and waterproofer with a retarder in it on top coat will give you more time before it goes off. You can top coat if you’ve scratched the next day at this time of year. Wet the wall before you scratch and the same for top coat. If it’s warm then give it a good soaking. 4:1 sand and cement for scratch and 5:1 for top coat. Top coat should never be stronger than scratch. No problem for all the questions and thanks for watching!

[@redsreds6598]

@@SamDaviesBuilder Thank you for the swift reply mate very kind of you. All the very best 👍

[@1978strong]

Great work.

[@SamDaviesBuilder]

Thankyou

[@randymarsh3636]

I always Sbr slurry before applying the scratch coat, it's ball ache but you know its never coming off the wall.

[@SamDaviesBuilder]

SBR is great stuff I agree. Apart from getting it off your hands at the end!

[@rmacc7]

Really nice job , how much would a wall that size cost ?

[@MrGofarkyself]

I’m watching from australia and here that job would be about 28 thousand dollars. And it would be about 4mm thick. Applied by an apprentice.

[@BillyOnYouTube]

​@@MrGofarkyselfUm. What??????

[@jonwillock3594]

Great job looks really good....I'm going to attempt rendering a brick wall this weekend, the wall I'm rendering is the back end of a terraced and the brickwork is 125 years old, crumbly and dusty too, would you pva it first? What would you recommend. Cheers

[@SamDaviesBuilder]

Jon Willock I wouldn’t use PVA. It’s water soluble so doesn’t work well outdoors. You can buy something like ‘rendagrip’ basically a paintable solution which enables the render to adhere to the surface. A good builders merchants will stock it. Just make sure any loose/dusty bits are removed first. Ideally pressure wash it. Check out my channel for another plastering video too!

[@EasterlyWind]

Did you use any sort of PVA or grip on the blocks before scratch coat? Does it just stick there no problem?

[@SamDaviesBuilder]

terry flynn the blocks had a good texture and the wetting of the wall provides suction. If you have a smooth surface I wouldn’t recommend PVA outdoors as it’s water soluble. I’d go for sbr and cement or ‘rendagrip’ which is a textured slurry you’d paint on before your scratch coat

[@EasterlyWind]

@@SamDaviesBuilder we have thistlebond here in Ireland.I am not sure what it is but its recommended by my builder providers so i will try that on smooth brick Thanks for reply

[@minnymichael2106]

Hi, how long do you wait to use the scratcher on the first coat and can you tell me how many bags of sand and cement was used for this wall. What’s the size of this wall. I have a 35sq foot stone wall to plaster over . Great job, thanks .

[@SamDaviesBuilder]

Minny Michael when it’s warm like it is at the moment then I’d wait 10 minutes until I scratch it. In the cold you’d wait a little longer. Basically if you start scratching and see anything move then it’s a bit too wet. You don’t want to leave it go off too much either so it’s a fine balance. With regards to quantities I was doing other walls on that job so I haven’t got a figure I’m sorry.

[@erikkopsala3564]

What is the minimum waiting time for the second render coat so water spray can be applied , is their a maximum time limit eg. If after scratching , it was left to dry out for days or longer would second coat still adhere successfully , thank you

[@SamDaviesBuilder]

Erik Kopsala you can go on the scratch the next day as long as it’s not been too cold. Don’t worry if it’s weeks or months later, as long as the wall is still clean and then wet it according to weather conditions

[@luketheskeletonboi1574]

If you are Plastering over a stone wall you need to scud it before you scratch it. 2 sand 1 cement with a bit of sbr for good measure. This mix needs to be very sloppy and is applied using a dasher ( Harling trowel). If the stone is uneven, you can rule off the scratch coat to make it easier for yourself when it comes time to put on the top coat

[@Twobirdsbreakingfree]

Whats the minimum wait time before applying the top coat?

[@SamDaviesBuilder]

I’d scratch one day and could top coat the next. Middle of winter you may have to wait a day longer though!

[@dkaloupis75]

Hi. How much plastering sand and cement? Also have you add any plastisizer in the mix and bonding agent in the questioned surface? Thanks.

[@SamDaviesBuilder]

Dimitris Kaloupis just plasticiser in the mix which is 4 parts sand and 1 cement for scratch and 5 parts sand and 1 cement for top coat. No bonding agent on the surface - if it’s smooth surface you would need some sort of bonding agent. I only had to wet the wall for suction

[@dkaloupis75]

@@SamDaviesBuilder You are a star, i will give it a go however if i will fed up by doing it,drop me your details and get that job here mate...

[@SamDaviesBuilder]

Dimitris Kaloupis I think Wales is a bit far from you I’m afraid 🤣

[@dkaloupis75]

@@SamDaviesBuilder oh lord...Southampton...

[@marathoniantrolled1]

Thought the scratching must be wave like, not horizontal.

[@SamDaviesBuilder]

Leonard Erasmus horizontal has always worked for me. I have seen it done wavy too. There is always lots of different ways in construction!

[@joecurran7889]

Yes as crooked as possible is the right way to reduce cracking..

[@bloggs692413]

@@SamDaviesBuilder wavey lines gives more key so less like to crack also use lime in mix more flexible also let it dry more before floatin or u can spray a light haze on it with a spray bottle if it has gone abit

[@SamDaviesBuilder]

bloggs692413 thanks for the comment. I’ve used lime before and have experienced fine cracking on the surface. With regards to a spray bottle yes that’s a good technique but I’d rather catch it earlier than rescue it with water. My horizontal scratching has always provided a good key but as I always say with building there is many methods to jobs so it’s interesting to see other people’s techniques.

[@mrgrunt4038]

Absolutely, just by using either horizontal or vertical lines can add shrinkage and cracking in the opposite direction. Best using big wave movement which minimises shinkage and improves the key. Good video though, well done

[@binola]

Do i have first have to wait when i made the scratch wall untill its dry?

[@SamDaviesBuilder]

Yea. You have to wait until the next day before you put your top coat on. I have made another detailed video on scratch coat only on my page if you want to check it out

[@binola]

@@SamDaviesBuilder Thx. One day ill wil try this. After plastering can i give it a Colour? Do i need a special paint. Nice weekend! Grz Ben form the Netherlands

[@SamDaviesBuilder]

binola yes you can paint but ensure it is fully dry, I like to leave it at least two weeks, longer in colder temperatures. Use a good quality paint and ideally water down the first coat to ensure good adhesion. Thanks for watching!

[@99marilena]

Looks great 👍🏼

[@SamDaviesBuilder]

michael gough thank you :)

[@355PH]

Great video 👍👍 True professional.

[@SamDaviesBuilder]

355PH thanks 😃😃

[@jbradanfeasa]

Excellent video, really clear. Sometimes the sponge finish on an external wall has a slightly stippled effect. Is this done with a wet or damp sponge? Thanks.

[@SamDaviesBuilder]

John Healy thanks! Just a damp sponge. I wring it out so water isn’t dripping out of it. It can be sponged in a downward sweeping motion or in a circular motion. And don’t catch it too late or it won’t sponge nicely, just after you’ve floated it is the best time

[@jbradanfeasa]

@@SamDaviesBuilder Thanks Sam. I'll give it a go :) Is there any particular type of sponge that works best?

[@SamDaviesBuilder]

John Healy just a normal car wash sponge is fine. Make sure the sponge is flat and not mis shapen or it will not give an even finish

[@robbieb3090]

That's a nap finish your thinking off.

[@tough2lie382]

You can do a nap Finnish using a car sponge or a raised nap using the same type of sponge that is used for skimming. Raised nap is harder to do but looks better when done correctly.

[@razze146]

What is your mixing ratio?

[@SamDaviesBuilder]

4:1 (4 sand 1 cement) scratch coat and then 5:1 top coat

[@newry123]

when rendering outside of the house do you put the waterproofer in the scratchcoat or topcoat or both ,,cheers

[@SamDaviesBuilder]

I would just use waterproofer in the top coat. Use feb (plasticiser) in the scratch. That is from my experience but other plasterers may be different.

[@lazergaming4195]

Does the final coat require Lime at all or does the plasterciser/waterproofer do the job on its own?

[@SamDaviesBuilder]

LAZER GAMING I don’t use lime and as you say let the plasticiser or waterproofer do the job. I only use waterproofer if it’s a wall where the rear side of it would be dry such as a shed or house wall. Some people do use lime in their mixes though!

[@djhago3123]

Use lime in the Finnish coat especially if you want a nap Finnish.. lime helps prevent hair line cracks also..

[@grassabrutta]

Sam, do you ever use lime instead of plasticizer in the base coat ?

[@SamDaviesBuilder]

No, plasticiser is so easy to use that I always use that. That's not to say you can't use lime though, its just the way I do it

[@ciaranduffy6330]

When you say plasticiser is that waterproofer ?

[@SamDaviesBuilder]

Ciaran Duffy no, but waterproofer will act as a plasticiser too. I only tend to use a waterproofer when it’s onto a cavity wall

[@newry123]

going to try and render a wall,what length and width of trowel should i get,cheers

[@SamDaviesBuilder]

I would get an 11" trowel if you are just starting out

[@newry123]

@@SamDaviesBuilder thanks

[@newry123]

thanks

[@tomasoconnor6456]

Hi Sam good vid. How much sand and cement is needed roughly for a 5 sq m wall? I’ll be using an 18mm stop bead. Thanks for your time. Tomas

[@SamDaviesBuilder]

Hi Tomas, thanks! You'd roughly need 250kg sand and 3 bags cement. Thats allowing for a bit of sand and cement spare as theres nothing worse than running out halfway through!

[@tomasoconnor6456]

Good man. 👍🏻

[@johnny545]

Hi Sam would ya get away without a scratch coat if I skudded the wall

[@SamDaviesBuilder]

Johnny sorry I don’t have experience with skudding so I can’t help you there. I know a lot of people commenting on here seem to have an idea with skudding

[@cosmic_sky_mountain]

@@SamDaviesBuilder i asked chat gpt : When plastering over a stone wall, the terms "scud it" and "scratch it" refer to specific steps in the preparation and application process to ensure a good bond between the plaster and the stone wall. Here's what each term means: Scudding Scudding is the first step in preparing a stone wall for plastering. This involves applying a rough, thin coat of a wet mix, often made from a combination of sand and cement, sometimes with added lime. This mix is thrown or brushed onto the stone wall to create a textured surface. The purpose of scudding is to provide a good key, or grip, for the next layer of plaster. Without this rough base layer, the smoother plaster might not adhere well to the stone surface, leading to potential peeling or falling off over time. Scratching Scratching refers to the second step after scudding. Once the scudding layer has cured and set sufficiently, a thicker coat of plaster, called the scratch coat, is applied over it. While this coat is still wet, it is scratched with a comb-like tool or a trowel to create grooves or roughness. This scratched surface helps the final coat of plaster adhere better by providing additional texture and key. The scratch coat is crucial for ensuring that the subsequent finishing coats of plaster bond securely and evenly. Summary Scud it: Apply a thin, rough coat of wet mix (often sand, cement, and lime) to create a textured surface on the stone wall. Scratch it: Apply a thicker coat of plaster over the scudded surface and scratch it to create grooves for better adhesion of the final plaster coats. By following these steps, the plaster will have a strong and durable bond to the stone wall, ensuring a longer-lasting and more effective finish.

[@eaglegummybears7112]

Did you put pva before scratch coat

[@SamDaviesBuilder]

eagle gummy bears no. As long as the wall is clean and you damp it down for suction then it will be fine. If it’s a smooth surface you are putting a scratch onto then an sbr and cement slurry should be painted on just before you scratch. Block work just needs wetting

[@tonyhilton7097]

Did you coat the wall with SBR or put it in the mix ? Or is it not needed ?

[@SamDaviesBuilder]

Hi Tony, not needed on a wall like this in my opinion. If you had a smooth surface like say engineering bricks you’d mix SBR with cement then paint it on the wall prior to doing a thing scratch. There’s enough grip on blockwork just to damp the wall and scratch

[@tonyhilton7097]

Mix with cement powder to make like a slurry and then paint it on the wall or just out of the tub ?

[@SamDaviesBuilder]

@@tonyhilton7097 mix with neat powdered cement like a slurry and paint it on. Make sure you apply the scratch coat while it’s still tacky so you’ll have to work in sections. Make sure your scratch is thin too or it will slide off the sbr

[@tonyhilton7097]

Got it 👍👍👍

[@tonyhilton7097]

@@SamDaviesBuilder is 24 hrs between coats ok mate ?

[@MariusMunteanu-y4n]

Whay you cover trdition ?

[@SamDaviesBuilder]

Sorry, I don’t understand

[@jlawlor7560]

Very helpful thanks

[@bslx]

artist at work

[@SamDaviesBuilder]

bslx thankyou 😄😄

[@mickinoz2005]

I have a wall only 5 blocks high in harden but long 16m is this something to tackle rendering myself i am fairly handy just concerned about that final finish not being spot on. Near impossible to get a plasterer (decent one)

[@SamDaviesBuilder]

What you could always do is split the wall down into smaller sections by using a stop bead or some baton on the wall. You may always see the join but if the wall is 16m long you'll end up with a crack somewhere due to expansion anyway (expansion joints every 6m generally on block walls)

[@mickinoz2005]

@@SamDaviesBuilder what are your thoughts on this single coat render products

[@SamDaviesBuilder]

mickinoz2005 I haven’t used any before - I do plan to in the future though!

[@stavebnifirmapikr9129]

I never understood how you make a wall plaster plumb by just troweling the plaster on it. In central Europe where I live we start off with putting plumb lines of plaster, let it dry and then we throw in the plaster in between, after that we use a straight piece of wood or a metal lath to smooth it out by draging it on the guides (plumb lines of plaster).

[@SamDaviesBuilder]

Interesting to see different methods in different countries. I suppose here as long as your wall is flat and true, then your scratch is straight edged along with your top coat then you will be pretty plumb! You can’t go wrong with plumb lines of plaster I suppose though.

[@stavebnifirmapikr9129]

@@SamDaviesBuilder That's how we do it in Czechia kzbin.info/www/bejne/maO1d4J4fNqpja8

[@SamDaviesBuilder]

@@stavebnifirmapikr9129 thanks for that. Such an interesting process! I’m surprised you don’t use beads and it’s true craftsmanship the way you do it! What’s your mix?

[@stavebnifirmapikr9129]

1 lime 2 cement 5 sand for interiors and for exteriors 2 cement to 4 sand

[@SamDaviesBuilder]

@@stavebnifirmapikr9129 2 cement is interesting, much stronger than our mixes. 4 sand to 1 cement is a pretty standard mix here

[@davidday866]

Do you wet the wall first if it’s dry

[@SamDaviesBuilder]

Yes you must wet the wall if it’s dry to help suction and stop it going off to quick. How much you wet it depends on the time of year too. You can’t wet it too much in the winter or it will take ages to go off

[@davidday866]

@@SamDaviesBuilder appreciate the reply sam. Tough find a block layer these days here in Ireland. My wife sent me on a 3 day apprenticeship and told me to do it. 😅 looks like I’ll be plastering too.

[@SamDaviesBuilder]

@@davidday866 I think trades such as block layers and plasterers are becoming harder and harder to find! Good luck doing it yourself, the key to it all is getting a good mix and you you’ll be fine!

[@SamDaviesBuilder]

@@davidday866 there’s a few more plastering videos on my page and also one about getting a good mix

[@davidday866]

That the gospel today I made a mix. I was so excited for it. The blocks levelled with a little wiggle. I learned the mother gets wetter as it mixes and slow down the mixer. 5 meters at a time. I’ve got about 40 meters to go 6 block high. I’ll get it before I’m done. I’m a steel fabricator by trade. Got to make railings and sliding gates. Shoul be all sorted by 2024 🤞😳

[@TugaemBristol]

if i want to do a white wall, do i have to use cement or is there another product in white color ? or any color other than cement?

[@SamDaviesBuilder]

You can use a product called K-rend which is already coloured

[@bh7791]

K rend tends to stain eventually anyway though right? Still have to masonry paint it in the end

[@SamDaviesBuilder]

@@bh7791 It could just be cleaned off periodically and it will come back like new. I am not a fan of K-rend though as from what I see round here (West Wales) it just gets green from the trees and doesn't get cleaned so looks awful, its the heavy texture in it that all the dirt clings to!

[@bh7791]

Yeah it makes buildings look so run down! I'm just about to render my thermalite double garage myself... I hear it's tricky!?

[@SamDaviesBuilder]

@@bh7791 If its thermalite then id suggest going over them with rendagrip or similar to get a good key and better suction

[@kennydeary957]

Is the top coat wet before rubbing down?

[@SamDaviesBuilder]

Yea but not too wet, if theres moisture coming to surface or moving on the wall it’s too wet

[@shane24v]

Do you have to do a whole area in 1 go, I only ask because after this video I'm tempted to try, but it's quite a long wall

[@SamDaviesBuilder]

Shane Scott you can always break the wall down into sections using stop beads

[@shane24v]

@@SamDaviesBuilder will the beads show on the wall or will I be able to blend 1 section into another

[@luketheskeletonboi1574]

Put 2 stop beads back to back with a 10mm gap. After it’s plastered, run some mastic into the gap. If the wall is very long this is good practice as it will help to avoid cracks in the future

[@SamDaviesBuilder]

Luke The Skeleton Boi totally agree with you there, good tip!

[@therarebreeds77therarebree7]

Wet the wall first?

[@SamDaviesBuilder]

I did 😃

[@shaunfowler1522]

Over trowled the first coat. Quick brings the moisture to the surface and prevents maximum suction. Also didn't use a featheredge on the first coat 🤔🤔

[@SamDaviesBuilder]

Cheers for the tips Shaun. I don’t use a feather edge on the first coat as I’m happy with how flat I put it on. Always grateful of advice as you never stop learning!

[@kennydeary957]

Is your top coat 4-1 too

[@SamDaviesBuilder]

Top coat always weaker than scratch so 5:1 we do it

[@willandelfie]

Do you ever use lime with your mix?

[@SamDaviesBuilder]

I don’t personally but I know lots of plasterers who do

[@ron1martens]

Nice video. Looks like concrete bricks. Do you use any additive in your mortar?

[@SamDaviesBuilder]

Ronald Martens yea it’s over concrete blocks. I use mortar plasticiser which adds air to the mix

[@ron1martens]

Sam Davies the Australian builders association banned plasticer because they wanted to promote the lime industry. I stopped using lime altogether when I came across an industrial chemist who stated we considered lime to be no good. I thought okay. So I worked with them and also used their plaster no lime. It's the best thing I ever did. It's more expensive. Does your work crack after a while once it's dried a few months time seeing as it's not drying?

[@SamDaviesBuilder]

Ronald Martens interesting! What does the plaster you use consist of? Have only experienced cracking from no expansion joints! Does your plaster crack?

[@soothingrelaxing123]

4:1 what does this mean?

[@SamDaviesBuilder]

4 sand 1 cement. There is a video about mixing on my channel

[@belga95]

Je ne comprends pas Pourquoi avoir enduit un mur qui était plus joli avec ses briques apparentes.

[@garydouglass9577]

Inside plastering outside rendering.

[@Lewiinn]

Tell me about it

[@MegaCuprar]

I used to stick some newspaper on the wall to draw out the water

[@SamDaviesBuilder]

MegaCuprar yea I’ve seen that being done in the winter. The weather is a nightmare for plastering as it’s never a constant factor and you always have to alter things to suit!

[@porogod1726]

I'm a painter by trade so have never plastered before and I'm looking into getting some block walls done for my back garden, after watching this I'm actually gonna have a go at plastering them as I'd love to be able to do something else for a change. Very informative and easy to follow. Thanks 👍

[@SamDaviesBuilder]

fran faherty thanks :). Great to see the video being useful!

[@joblogs542]

Boss job that lad how much to do my wall

[@SamDaviesBuilder]

Cheers! What size is the wall?

[@joblogs542]

It's like 4 foot high and aba 20 feet long lad

[@joblogs542]

Just a front garden wall

[@mr..indian1718]

I am Indian All congratulations job 👏

[@SamDaviesBuilder]

Thankyou so much 😀😀

[@cosmic_sky_mountain]

do you use pva

[@SamDaviesBuilder]

No, pva is water soluble so you shouldn’t use it outside. If you want to get something to help the render stick then use rendagrip or SBR mixed with cement

[@cosmic_sky_mountain]

@@SamDaviesBuilder can i mix pva with the render mix

[@SamDaviesBuilder]

@@cosmic_sky_mountain why do you want to mix pva with it?

[@cosmic_sky_mountain]

@@SamDaviesBuilder i thought it could make it waterproof , but i understand now that it wont work , so can i mix sbr with my sand cement mix to make that better at weathering ?

[@SamDaviesBuilder]

@@cosmic_sky_mountain you can get a waterproof additive to go in the mix like this: www.sealantsandtoolsdirect.co.uk/feb-febproof-plus-waterproofer-plasticiser-admixture-5-litre-fbproofps5?language=en-gb&currency=GBP&gad_source=1&gbraid=0AAAAADx-2OJx9gMin03eJOjp45aECrKZc&gclid=EAIaIQobChMI8M7Sya7HhwMV55NQBh1cRQmLEAQYDCABEgKJOPD_BwE

[@djhago3123]

I don't like to see plaster going on without a scudding.. but that's the way I learned to do it

[@SamDaviesBuilder]

dj hago I’m not actually sure what scudding means? Always open to seeing other way things are done

[@djhago3123]

Mix sharp sand and cement at 2 to 1 really wet with no plastisizer... and throw it on with a scudding spoon for first coat .. leave it a day then scratch it.

[@djhago3123]

It keys to the wall alot better

[@SamDaviesBuilder]

dj hago ah I have seen that on a lot of Irish house build accounts on Instagram. I wondered what it was. I see it done before they clad a house in stonework too

[@robbieb3090]

@@SamDaviesBuilder youd be ran of an Irish site without scudding your walls before scratch coat.

[@naqi16]

For both scratch and top coat, once applied how long do you have to wait until you can rule it off ? Also can you explain your sand and cement mix consistently? These are the only 2 things I have trouble getting right. Great Vid by the way :-)

[@SamDaviesBuilder]

Basically when you rule off you want to make sure it is dry enough not to move it about on the wall. It’s a fine balance as you don’t want to leave it too dry before you rule off. I can’t give a time on how long as it depends on weather conditions for how long it will take. Here is a link to my video on how to mix: kzbin.info/www/bejne/bpXblKNofN6Ears Thanks for watching too :)

[@bjpijpers6183]

Wats your meter price ,??

[@SamDaviesBuilder]

Most jobs I do are by the whole job price so I don't have a meter price. It's usually worked out by how long I think it will take me. Sorry I can't help with your question

[@Rizkadanihsan]

nice

[@SamDaviesBuilder]

Thanks!

[@indigo19865586]

Where is the bell cast beads

[@SamDaviesBuilder]

indigokid jjj2 bell cast beads are purely a cosmetic feature these days. We didn’t want them on the wall - most walls I do wouldn’t have a bell bead. Historically you’d have them on a house or chimney to shed water away from the base of a wall but now with modern DPC’s and paths being 150mm lower than DPC then a bell bead has no function apart from cosmetically.

[@Rureal42]

I always seem to leave sponge marks no matter what I try. Very frustrating.

[@SamDaviesBuilder]

Hi Colin, what sort of sponge are you using? Fine texture works best. Also make sure it’s wringed out and damp, if water is dripping off the sponge it’s too wet to use on the wall.

[@Rureal42]

@@SamDaviesBuilder yellow rectangular sponge that people wash their cars with. Perhaps I should try another.

[@SamDaviesBuilder]

@@Rureal42 those sponges usually do the trick! Are you doing a circular motion with the sponge?

[@Rureal42]

@@SamDaviesBuilder yes circular.

[@tough2lie382]

Good job but it's easy to do a good job on such a small area

[@SamDaviesBuilder]

Tough 2 lie thanks. Yea the test is if you can do it on a big gable end!!

[@tough2lie382]

@@SamDaviesBuilder no disrespect intended, it's not feasible to do a tutorial on a big table I understand.

[@tough2lie382]

@@SamDaviesBuilder sorry gable

[@SamDaviesBuilder]

None taken, I dread the thought of doing a big area in this weather!!

[@amerh4190]

Hi mate, looks good. Did you use sharp or soft sand for the render?

[@SamDaviesBuilder]

Amer H I used building sand. Sand quality is so different in different parts of the country it’s difficult to say how my building sand might compare to yours. Your local merchant may even do plastering sand to buy

[@sirxenon6855]

But what's the purpose of plastering an outside wall?

[@SamDaviesBuilder]

To make it more presentable and provide a good surface for painting

[@sirxenon6855]

@@SamDaviesBuilder appreciate it

[@HGarry4012]

First scud the wall show blocks won't show through Right to left on sand and cement and your mix looks like way to much plaz

[@SamDaviesBuilder]

We don’t scud the wall in these areas. Always interesting to see different methods in different areas. Definitely not too much plasticiser, I just make a good mix. I’m a big hater of too much plasticiser!

[@deckostreams3940]

I like your shoe, anyways! :-)

[@SamDaviesBuilder]

Amazing Construction Channel thanks 😃

[@leecasper6657]

"aim for 12,5 mm thickness" Sure :D

[@SamDaviesBuilder]

I know, it usually ends up being thicker!

[@thebotaneer840]

@@SamDaviesBuilder I do 3mm each

[@SamDaviesBuilder]

@@thebotaneer840 what product are you using for 3mm?!

[@thebotaneer840]

@@SamDaviesBuilder K-Rend

[@Metubeforvids]

Ok render beads are only 15 ml that's to allow for a 5ml scratch and a 10ml top, you didn't put a bell bead at bottom and you were that slow the render was tearing as you were ruling but overall was a decent finish 👌

[@SamDaviesBuilder]

Steven Williamson cheers for the comment. Bell beads are depending on what the customer wants. I say there’s more jobs without bell beads. And beads aren’t 15mm, some of the plastic ones might be but the metal ones are just mesh so you can make them anything you want. But the thing with this job is everyone is different and people have their own ways. I’ve never been about speed to be honest, it’s worked for me so far. Appreciate the comment anyway :)

[@Metubeforvids]

Mate I'm not trying to criticise I'm just trying to help if you rule up as you go would be much easier and speed up it does have to be layed on perfect the rule will sort all that as for the bell bead if you don't put one at bottom moisture will get behind the render and the bottom will fall off in a few years it not criticism mate just fact

[@SamDaviesBuilder]

Steven Williamson I disagree on the bell bead. The bell bead is cosmetic a lot of the time. Before DPC’s were invented then a bell bead would have thrown water away from the bottom of the wall. On a garden wall it is rare to see a bell bead. And I usually always rule off once is all on - if you wet the wall correctly then you don’t need to stop halfway through to rule off. Like I say everyone has their own opinions on this and that’s the beauty of life

[@CUBABLOCKMASONRY]

👍👍👍👍

[@SamDaviesBuilder]

Thanks 😃

[@matoko123]

Good video but why put a 25mm render on a garden wall? No insulation is required as on a house wall. Better to buy a special finish that would go on in one coat at 3mm.

[@SamDaviesBuilder]

25mm of render isn’t for insulation properties. Sand + cement render is cheaper than the specialist coloured renders plus those (especially K Rend) coloured finishes can be pretty course and get dirty quickly as the dirt sticks in the course texture. Coloured renders do have their place though!

[@rodneygilbert6832]

No scud coat that is most important key before scratch.

[@SamDaviesBuilder]

Rodney Gilbert hi Rodney, no scudding around here. Where abouts are you? Seems to be a popular technique in Ireland