Aircrete Blocks Cracking up - Unwanted Trouble

Рет қаралды 452,561

3 жыл бұрын

Why do aircrete blocks crack up so often? As with so many of these problems, everyone involved is pointing a finger at someone else. Is it the blocks, the brickies, the plasterers or the architect who is to blame?
Aircrete blocks are lightweight and have a very high degree of insulation. When introduced, they seemed like the wonder product of the age and to some extent, they do a job that no other materials can do.
I think it’s accurate to say that when they were first developed the intention was to use them on internal skins of cavity walls instead of breeze blocks which are heavier and not such good insulators.
This is still where they are mostly used. There are however a growing number of buildings being built with external skins of Aircrete and there are even buildings being built with solid Aircrete. That is to say no cavity.
The appeal of Aircrete blocks over bricks is speed and cheapness. They are a good product in their way but the builder needs to understand their limitations.
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#Aircrete #buildingmaterials #construction
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Пікірлер: 810

@branwensloper8197 8 ай бұрын

This is so interesting, expecially in light of the widespread aircrete issue recently announced in 100s of UK schools and municipal buildings.

@SkillBuilder 8 ай бұрын

More to come on that subject is a couple of days time

@davebell4917 8 ай бұрын

There's a couple of differences in the naming, but these blocks look to avoid the worst risks of the RAAC story in Britain. What I know of that scares me is the long panels and beams. These blockwork walls are under compression loads. The RAAC beams and panels, supported at the ends, get a tension load at the lower side. The descriptions I have seen include other problems, associated with the reinforcement, which I don't see any sign of here. But this video showed a couple of details that could be easily missed - the strength of the mortar and the expansion joints. The RAAC failure mode seems nasty - less warning time than we were promised for an ICBM attack.

@whirled_peas 8 ай бұрын

@@davebell4917 just on the face of it, anything-crete under tension is simply bad engineering, end of.

@ziggarillo 7 ай бұрын

That is an RAAC issue, not aircrete. Different stuff used very differently

@harveysmith100 2 жыл бұрын

As a fifty five year old bricklayer this lack of basic knowledge drives me nuts. We used to have Clerk of the Works on sites monitoring the standard of work and materials used. They got rid of them and the problems like cracking started. Instead of asking the tradesmen what was happening the college boys thought they knew best and started coming up with all these solutions, expansion joints, stainless steel rail tracks etc. These new ideas actually weaken the wall in a secondary way. Roger was correct when he said, you shouldn't use a mortar stronger than the material you are using. Any building older than a hundred years ago had no cement whatsoever, it was all lime sand mortar with no cracking problems. Most modern problems are the engineers being obsessed with strength, "Strength is better so make the mortar stronger." No, that is the cause of most of the problems. Go look at a terrace row of Victorian houses, nine inch solid walls a street long, not a single crack from one end of the street to the other. Go look at huge Georgian houses, no cracks. Go look at huge Roman buildings that have stood for two thousand years, no cracks. But of course, we need to make our mortar stronger and add reinforcement to it. Is it me?

@FlamesOfThought 2 жыл бұрын

Couldn't agree more. Top comment

@harveysmith100 2 жыл бұрын

@@FlamesOfThought Thanks Jack. We just know

@thertis580 2 жыл бұрын

Was a subby 40yrs. You're spot on. I would add that every sand has different characteristics when mixed. And a simplistic specified formulation of 5:1 or 6:1 etc always catches the college learnt guys out. It's practical application that determines a mix.

@harveysmith100 2 жыл бұрын

@@thertis580 I agree, gone are the days when you could walk into a builders merchant and ask them what soft sand they have. Now theY say, it's just builders sand. How I long for a bag of Runfold or Westerham. (The local sand quarries when I was a lad)

@trevorleggett1777 2 жыл бұрын

@@harveysmith100 dont forget to add,every render coat,is weaker than the last one applied. As you head to the finish coat

@memyself7413 2 жыл бұрын

I love these “Skill Builder” videos, and the way that Roger explains things is a breath of fresh air and easily understood.

@handymanr4729 7 ай бұрын

Something about the old pom builders thats just so straighforward, no knocking around - Pure and simple. Not like those americans blah blah bah

@lelandcarlson1668 2 жыл бұрын

A skilled tradesman is invaluable. I'm always amazed at how many details go into a trade like masonry or carpentry. Great video!

@richardcapey-wade8191 3 жыл бұрын

Spot on Roger, doing exactly that on my extension, doing it all myself as didn't trust any brickies at work (I'm a carpenter) Only one guy ever used lime before ,when he was an apprentice, they don't seem to learn much, as a proper bricklayer is a skilled and comprehensive trade when you get into it, but as most trades nowadays it's watered down to a basic craft for speed etc needed to get that off the chest, cheers

@Carl-yu6uw 3 жыл бұрын

Same here - building my extension for that very reason. Asked the mortar question yesterday to a bricky in screwfix who replied they use exact same mortar on both skins, concretes and aircrete.

@jamieroberts6904 3 жыл бұрын

Lime is the way forward

@scottnever8732 2 жыл бұрын

Sorry richard for your experience but I do agree, the need for so called tradesmen/bricklayers was so high they invented an NVQ. worst thing that ever happened to my industry. passing people within 6 weeks for a job that took at least 3 years to learn with intensive training . Blokes that I learnt from were on a 7 year apprenticeship

@johnclements6614 2 жыл бұрын

@@scottnever8732 There are too many things that only come up now and again to be taught in 6 weeks. People also do not remember everything they are taught first time. You get decent craftsmen if they do a year in the classroom then a couple day release. then they get to be on different sites and see different things and problems.

@rob-123 2 жыл бұрын

@@scottnever8732 NVQ? Not Very Qualified...

@zeez9053 3 жыл бұрын

Way impressed what a total clear and concise video with everthing gone through and fully explained 👍🤘

@UberAlphaSirus 3 жыл бұрын

Yhea, I am absolutly allergic to wet trades and ground works. So it's a nice head up on stuff I don't/won't get involved in. I can't knock this lot to be fair. Sometimes there is a a bit of a fuck up, but you have to piss with what you got at the end of the day.

@hectorheath9742 2 жыл бұрын

Bollocks, he says the weight of a JCB and he'll have meant an RSJ. Re cracks he's saying the cracks will be in the mortar if the mortar mix is 'right'. How is that better? And Nm (Newtonmeter) is not a unit of pressure, and 3.5 Newtons is like 4 apples of weight so that can't be right either. He mentions reinforcing mesh in the mortar; he should have said the first coat of plaster. The aerated blocks in my extension are riddled with cracks..bottom line ..aerated blocks are a crap building product.

@UberAlphaSirus 2 жыл бұрын

@@hectorheath9742 The problem is you think you know, but have no idea.

@hectorheath9742 2 жыл бұрын

@@UberAlphaSirus Oh really, Sirus? You've gotta defend your comment with a reason or reasons. Tell me what's wrong with my accurate review of this shabby vid. But you'd better read the rest of the comments first.

@UberAlphaSirus 2 жыл бұрын

@@hectorheath9742 I told you already. "The problem is you think you know, but have no idea." I read everything you and others said before. What do you want me to do? I can't un thick you.

@TheSnekkerShow 2 жыл бұрын

This was eye-opening and helpful. I never thought about the consequences of mortar being too strong.

@markhaynes6410 3 жыл бұрын

Didn't he do well kids?! Only the slightest glint in the eye when the background noise started 😂😂😂 Great little video though, informative as ever.

@allanmcintosh3347 2 жыл бұрын

The mortar doesn’t hold the blocks together, it holds them apart. Grin.

@SkillBuilder 2 жыл бұрын

could something not do both? double grin.

@SirGregory 2 жыл бұрын

[grin] I like the use of plain English emojis. [wink+thumbs-up]

@doordye6503 2 жыл бұрын

Say what..

@FelonyVideos 2 жыл бұрын

He's right, you know. Most masonry is very strong in compression, but useless in tension. That is why a shifting foundation always yields cracks, and never smushes the grout out of the joints, and you never see bricks crushed.

@paulhunt8743 2 жыл бұрын

that's why they used lime it accommodates for movement lime is a softer mix that cement

@richardross7219 2 жыл бұрын

Very interesting. Many years ago as a teenager, I mixed mortar for my old man when he was laying block. That built up my muscles fast. We used lime in the mortar. I became an Army Combat Engineer and a Civil Engineer. I avoided using bricks and blocks because I found that there was too much inconsistency with our masonary work in my area. Very good video. Good Luck, Rick

@brettarmstrong4040 2 жыл бұрын

So so so refreshing to listen to someone who has knowledge from experience and not someone talking about what they did last Tuesday for ten minutes and two minutes on what you clicked on, based on what they think from watching someone else doing it on KZfaq Job well done and a job done well!!!

@metropolitandream 2 жыл бұрын

OUTSTANDING explanations. It pays to attend to these details if you want a lower maintenance home. Super helpful info.

@Cruner62 2 жыл бұрын

I'm not a bricklayer but I am a qualified engineer so when I built my own home I read up on this in detail and consulted my inspector. We decided upon using a 5/1/1 mix for the mortar one was lime. We also looked at where to put an expansion joint in a 12m front wall facing the sun. There were four windows in the ground and first floor ( Brick faced and 7n 140 mm light concrete block internal) in the 22 years there has been no cracks inside or out. We did fit bison Hollow core planks 8m single span that also helps to prevent movement of the inner leaf by absorbing the heat and cold expansion/contraction with underfloor heating to maintain a consistent temperature level., also we kept the windows on both levels 1.2 m from the corners to avoid stresses there Hope this helps.

@JehuMcSpooran Жыл бұрын

Dad made the brickie use lime in the mortar with our first house that we built back in 87. None of the brickwork has cracked even though other parts of the house had moved. I don't know what the ratio was but it has lasted.

@ksptm4 8 ай бұрын

It’s like you knew about the potential RAAC issues before they were made public knowledge. It’s a pity that those in power and authority do not consult skilled and experiences engineers such as yourself. Love your channel, as an electrical engineer, I still find it fascinating and your delivery of information is on point. Absolute professional and fantastic educator. Wish you all the success with the channel

@ericconnor8419 7 ай бұрын

This is aircrete, the bubbles come from aiding aluminium powder. RAAC is made in an autoclave and has reinforcing (giant pressure cooker) It stands for Reinforced autoclaved aerated concrete

@golfhacker9051 2 жыл бұрын

Precise, well worded, simply explained and no unnecessary drible.

@ML6103 2 жыл бұрын

Regarding the mortar not being stronger than the brick. This now makes sense why the 'hebel' blocks produced in Australia have their own specific mortar. Very good to know and thanks for the video

@habsom1406 2 жыл бұрын

Fascinating! Would never have thought you can have too strong a mortar but hey you live and learn, thanks Roger! Good job I'm not a builder ha! Really clear and well presented video, top class production.

@FlamesOfThought 2 жыл бұрын

Thank you and I hope you are alright and in good health Rodger - you're a treasure in the trade

@shaunglendinning 3 жыл бұрын

Great advice Roger!

@MrMatiDi 2 жыл бұрын

Amazing - the quality of these tips and advice can put many a college to shame. Good job

@rauldemoura2417 2 жыл бұрын

Very useful tips. I especially liked the tips about the different mortar mixes for block and brick. I never knew that! Of course, I’m no concrete or brick laying expert. Thanks!

@EireFirst1916 3 жыл бұрын

I only saw this on a new (ish) build,googled it - found the video, result = explanation / relief.. Nice 1 Roger 😅

@Aaron-gl8cm 3 жыл бұрын

Movement joints for blockwork are approx 6m in any straight run and 3m from a corner. This can extend to around 9 and 4.5m if you use bed joint reinforcement. It's closer to the corner as it's a point of high restraint. I say "approx" as if you were to put a joint after say 7m it won't definitely crack it will just have a higher chance of cracking. Roger, you hit the nail on the head with the mortar.

@glenr834 3 жыл бұрын

Such a legend Rog!

@OttoTheWeim 2 жыл бұрын

Here I am watching a British man talking about mortar and air Crete with no general usage for this information aside from personal knowledge. Great presentation and now I can maintain a conversation about the subject with my mates that are in construction.

@terrymontague7946 2 жыл бұрын

Many thanks for such a clear explanation. I now understand why the block walls inside my internal garage have cracks in them. The house is around 25 years old with dot and dab hiding most problems but not in my garage.

@lightning9279 2 жыл бұрын

Roger, well done. Straight to the point with the facts. 👍

@FSM925 2 жыл бұрын

I love how the way he demonstrates it moving “in and out” at 1:34

@neroc1 3 жыл бұрын

another excellent video, ive been told to keep the block dry as well , thanks for sharing your knowledge.

@SkillBuilder 3 жыл бұрын

Yes it helps to keep them dry but that is not always easy to do.

@SoundAssault 3 жыл бұрын

Great video - I learnt a lot there. Thanks Roger! 👍🏻

@johncoppock3823 3 жыл бұрын

Thanks Roger for great video, loads explained. Have seen new builds (not particularly big) where expansion joint hidden behind drain pipes at corners. That alarmed me that the gable then does not appear restrained properly (unless there are some hidden straps or clever ties). Suppose the roof timbers though might have more restraint straps and perhaps the floors also to keep it all together.

@Lou.B 2 жыл бұрын

Great video! Fascinating and very knowledgeable, Roger! Thank You!

@eamonhannon1103 Жыл бұрын

Excellent advice Roger !

@terrytytula 2 жыл бұрын

Really enjoyed the video, don't know anything about brick laying. I just replaced the vinyl on my house, and had to follow the same rule about allowing movement, in my case to prevent buckling and distortion.

@jamesswinyard530 3 жыл бұрын

Great video Roger!

@DJ-uk5mm 3 жыл бұрын

Excellent advice. Thanks for sharing

@OB-LA 2 жыл бұрын

I liked the presenter right off, he just sounds and looks like a journeyman, expert builder.

@Mariazellerbahn 8 ай бұрын

My house was built by Redrow in 1997. Lots of these celcon lightweight blocks visible in the loft, a lot of them cracked and I noticed whilst being built that the upstairs floor joists are are laid on these blocks where I would have put a wooden flat bearer to spread the weight. I have also noticed that the celcon blocks have also been used underground in the main foundations.

@robmaule5715 3 жыл бұрын

Bloody brilliant 👌🏼🏴󠁧󠁢󠁳󠁣󠁴󠁿👍🏼

@ivornotion6624 2 жыл бұрын

Feel like I am repeating the praise levelled at Roger from the many comments below but without the effort Roger puts into these videos the world is a poorer place. 'What we do in life echos in eternity' -

@SkillBuilder 2 жыл бұрын

Thank you Ivor.

@spanishpeaches2930 3 жыл бұрын

Used thin joint on my extension and used reinforcement every couple of layers. Used monocouche rendering on the outside on the blockwork. Much better, and a better finish.

@LADYMONA 2 жыл бұрын

Your work's so neat. Thank you for this.

@thescouselander5531 7 ай бұрын

Very interesting. I was always worried about these blocks in my old house - drilling into them was like drilling into fresh air and they generally seemed extremely weak.

@noelmoney6757 3 жыл бұрын

Great job once again, thank you.

@ljens8485 2 жыл бұрын

This fella is outstanding.

@katabrontes 3 жыл бұрын

Hi Roger, it's the same here in France. Sadly you often see stone walls repaired or repainted with cement instead of lime mortar. Trouble ahead I am sure. Mike

@BlueBeeMCMLXI 7 ай бұрын

Thanks, Roger, that opened my thick head up. You have saved me a lot of bother. Good man!

@greymase 2 жыл бұрын

Thanks, Harvey. This was SO incredibly helpful. I have watched hundreds of aircrete evangelist videos, and none have addressed this. QUESTION: Does using something like basalt fiber in the concrete with which the bricks are made abate this problem as well?

@chadcooper7348 2 жыл бұрын

Really appreciate this video! Question: What are your thoughts regarding AAC blocks that are interlocking? And, the mortarless stacking of blocks (expect for first run of blocks on slab or cmu block stem walls) in which closed cell foam is applied instead?

@p2as33 3 жыл бұрын

Another interesting video, you explain these things really well.

@SkillBuilder 3 жыл бұрын

Thank you very much!

@michaelharrison9340 2 жыл бұрын

Bed reinforcement (such as by BRC) is available, laid typically in alternate the bed joints to allow the movement joints to be spaced further apart or even omitted.

@mikepeters9887 2 жыл бұрын

This is excellent - very thorough!

@murraymadness4674 2 жыл бұрын

I also thought lightweight concrete was a great way to save time, mortaring blocks of them vs pouring a tilt-up wall seems backwards! Anyway great video, concise no nonsense

@petergambier 2 жыл бұрын

Thanks Roger, sound advise thanks. Lime spread here, I don't like to see expansion joints or use angle-bead on corners but I can see why they are necessary. At the start of the pandemic I built a 7 meter, half-round, rubble stone & old brick lime putty mortar wall without a concrete base and no expansion joints about 4 foot high, 3 stones wide with a stone & mortar infill to hold the end of my veg garden in. Finished in 3 days (lots of big stones) and about a year later big cracks suddenly appeared right from top to the bottom in 3 or 4 places almost where the expansion joints would have been. From the end of the wall to the first crack was about 2m.

@aileenjohnson1508 2 жыл бұрын

Smashing video did not realise how important mixes were when dealing with different tasks, I amgoing your and build a small seating area which will be inside a breeze block walled area, and hopefully render so this video has been sooooo helpful thank you

@nc3826 2 жыл бұрын

thx for sharing your years of practical experience, detailing what to do to help prevent Aircrete Block cracks.... and a few good tips for working with any cementitious block... But your main point is hire trades people who have a pride in their work, and will not cut corners.... Since knowing what to do vs doing it are 2 different matters... But even then you need other people such as the general contractor or ourselves spot checking its done to specs.. Check it 2x (or 100x) times and cut once is good general rule....

@petemoring67 3 жыл бұрын

Roger Bisby & Common Sense ..... Always in the same room together :-)

@nickcollins1289 3 жыл бұрын

Brilliant channel. Full of useful information

@SkillBuilder 3 жыл бұрын

Much appreciated!

@martinlouden9005 8 ай бұрын

Cracking bit of advice there Roger!

@chekymonkey4452 3 жыл бұрын

I could not agree more with that video. well explained

@beatonthedonis 2 жыл бұрын

In Central Europe most interior plastering and exterior rendering uses fibreglass mesh embedded in a flexible adhesive, then topped with a flexible silicon render. It leaves a more textured finish than finishing plaster, but is less prone to cracking.

@mpdavis731 2 жыл бұрын

And I thought this was about laughing blocks - still, enjoyed it and subbed. Thanks!

@markanderson6969 3 жыл бұрын

We've all known about the mortar being to strong for years but nothing changes especially on new build with silo muck, same old story quantity over qaulity

@MrB3ngy 3 жыл бұрын

Agree silo muck is used for concrete/thermo lite/ and the many different bricks used on site. Whether there engineering brick or soft stocks. That’s why these new houses have massive shrinkage cracks when the thrown up in the depths of winter.

@workdevice7808 8 ай бұрын

Wow! Excellent presentation and superb information. Thank you!

@EssGeeSee 2 жыл бұрын

Thank you for this.

@ca2712 7 ай бұрын

Thank you for for aharing these tips!!!

@moki888 Жыл бұрын

I'm planning an AAC facade/wall and wondered about using the panels or like one commenter asked, the interlocking block. Any info on those would really be appreciated! Great video!

@akesha4138 2 жыл бұрын

Thank you for educating the uninformed, enjoy learning about this topic.

@davidelliott5843 2 жыл бұрын

I rendered my concrete blocks with Tyrolean cement. Spattered on a first coat and allowed to cure. Then sprayed a second coat which was wood floated while wet. I hand planned on a third spatter coat but the smooth was so nice I left it smooth. That was in the mid 1980s and the wall still looks great.

@simoncooper8272 2 жыл бұрын

The problem is typically inherent with a wrong strength mix! The mortar joints need to be at least 10% less strength than the material being laid,

@brandonspivey8020 2 жыл бұрын

Great clear explanations .

@neuvocastezero1838 2 жыл бұрын

Excellent presentation!

@SkillBuilder 2 жыл бұрын

Thank you kindly!

@patmat. 2 жыл бұрын

Awesome explainations, thank you.

@MrEtonmess 8 ай бұрын

Excellent video. Sounds like a ‘wonder block’ which creates more problems than it solves. I drive past the 100+ year old terraces and wonder how far we have come. Fast fashion, fast food, fast houses?

@jinron24 2 жыл бұрын

I've noticed here in the states that building construction has taken a turn for the worse, materials are sub-standard, workmanship is atrocious and a general lack of pride in what's been constructed. Back in the day we had trade school education in regular high school, now all that is gone. I don't know if you see this where you are or that maybe it's a touchy subject to comment on!

@colmreynolds9869 2 жыл бұрын

The more houses fall down, the more new ones you get paid to build.

@colmreynolds9869 2 жыл бұрын

It's common sense to me when you see castles from the 1500's still standing and luxury apartments from the 80's collapsing and killing people. If we still built our buildings like they did in the dark ages, they would all still be here and most builders would be out of a job.

@metagen77 2 жыл бұрын

@@colmreynolds9869 Take a look at the heating bill of a castle and you will wish the ceiling had collapsed on your head instead.

@bobf1290 3 жыл бұрын

Everything he said was bang on 👌

@m4inline 2 жыл бұрын

We use Ytong a lot where i live. With that stuff you afe supposed to use their recommended mortar and no more than 3mm thick. That looks like a ton more mortar there than they use here

@richardgraham2303 8 ай бұрын

Excellent mate spot on 👍🏴󠁧󠁢󠁳󠁣󠁴󠁿cheers

@mmpod70 7 ай бұрын

Very well explained - you should lecture Specification writers and Building Designers - best explanation I have heard in 30 years Cheers keep up the good work.

@rickygray222 3 жыл бұрын

Those aircrete always make me nervous, they’ve got the consistency of a wotsit

@gbwildlifeuk8269 3 жыл бұрын

A wotsit? I dont know what is it?

@800Viffer 2 жыл бұрын

AKA a "What's it"

@FlamesOfThought 2 жыл бұрын

@Bercilak de hautdesert a puffy air-filled one

@EzeePosseTV 2 жыл бұрын

Wotsit! What a Whopping Whoosh!

@romanszefler7479 2 жыл бұрын

Hmmm.... ? Looks like that's a trade of personality BEING NERVOUS. Just do something even if its wrong

@waffle_chair9269 8 ай бұрын

Brilliant video.

@PBG762 2 жыл бұрын

aircrete was design as filler material for partition/non weigh bearing walls. supposed to be put inside rigid cadre that takes the load- key word rigid. So steel/wood frame = no go. Should go under concrete frame-post and beam, even that will give you crack at joints, so best option drywall/mesh-fiber glass of chicken wire over.

@alext8828 2 жыл бұрын

Best teacher in the world.

@barry-cq4xg 2 жыл бұрын

Great stuff. It is always good to learn the correct method and not the quick bodge to finish the job, get paid and move on to the next (bodge).

@shinigamilee5915 2 жыл бұрын

This guy really cracks me up! 😂

@simonharper4199 2 жыл бұрын

i was told many years ago by a long retired foreman who went to see Celcon blocks being made ( from one massive block and the wavy lines in the blocks are the marks of the saw teeth that have cut them up) that the manufacturers specified laying 100mm expanded metal lath into every third horizontal course . Goes to say that ive never seen it done.

@SkillBuilder 2 жыл бұрын

That is true

@mythoughts1................1 Жыл бұрын

Excellent video, great information.

@mattphillips9107 8 ай бұрын

Lol this is now a scandal 2 years after you posted this. Nobody listens!

@jwatkins5155 8 ай бұрын

No... You're talking about RAAC this is a different material

@scottnever8732 2 жыл бұрын

totally agree but along with that each face of a building is susceptible to different conditions , also mortar is now supplied by mass filled silo

@garydickenson3603 2 жыл бұрын

I did not understand 100% of the jargon but the parts I am familiar with was educational. Thank you. Question: Given stainless steel is non-magnectic how can I tell if the brick layers have actually installed the reinforcements when the job is inspected? Typically with metal rebar a magnet is used to verify that the rebar was actually installed.

@californiadreamin8423 2 жыл бұрын

The same principle described here, applies to brickwork, particularly pointing. Too strong a mortar could lead to shrinkage cracking of the joints and even brick fracturing, particularly on soft dry brickwork....a good soaking helps to give good brick mortar adhesion. In restoration work on really old brick, a lime sand mortar, no cement, may be required. A controlled small amount of cement may be added to help the mortar “go off” a little quicker, but there is a lot to be said for avoiding too quick a build, to allow the brickwork time to settle under its own weight. I don’t know if the Brick Development Association still exists but 40 years ago I found their data sheets very informative when I worked for a small civil structural consulting engineering practice.

@SkillBuilder 2 жыл бұрын

Yes the BDA is still around but is largely a marketing arm rather than a research body. I agree with what you say but fast track has made lime mortar uneconomic.

@SigurdVolsunga 2 жыл бұрын

Research has found you shouldn't add any cement to lime mortars, they work best when they are just the lime. Any pre WW1 house is probably built with lime mortar, and any repairs on it should only be done in lime, using cement will cause brick damage and dampness.

@topflightmechanic8692 Жыл бұрын

I don't even work in the construction industry but that video explanation was well done

@johnnavarro9169 2 жыл бұрын

Good info, I am just about to do my walls that have a concrete skin 100 mm thick and aircrete 400 mm behind that. There is 3.0 metres between columns . Was designed for half metre earth pour walls originally. Thanks for your info.

@PJ_CJ 8 ай бұрын

I put lime in my block mix that helps lots and makes the mix lovely

@infowarrior911 3 жыл бұрын

Brilliant info 👌 thanks

@espats9212 2 жыл бұрын

That’s why we use either glue or mortar of 1mm in Europe, both for cracking and to not loose the insulation properties

@SkillBuilder 2 жыл бұрын

I have used thin joint adhesive and still have cracks. I think it is due to the moisture in the blocks. They shrink as they dry and the glue holds them too tight. Answer dry blocks

@michaelkeister8689 2 жыл бұрын

Very helpful, thank you!

@johnboughton7451 8 ай бұрын

Extension at 35A I loved that series of videos featuring a very young Robin Clevet

@ireallyreallyhategoogle 2 жыл бұрын

I know nothing about all that, yet i still understood most of it. I was expecting a video about why aircrete is bad, but this is much better.

@bluevanmani 3 жыл бұрын

I know what your saying roger but we only use fibrelite blocks now and just upgrade the insulation batts no problem with cracking.just looks crap if you see any cracks worries the life out of the clients😄