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

I'm from Brazil and I've always found it funny that in my country that doesn't have hurricanes and earthquakes, our houses are real fortresses of concrete blocks or bricks, columns, beams, slabs and plaster, all made with cement, sand, water, lime and iron. You Americans have earthquakes and hurricanes, and your homes look like movie sets. Worse, with wood that always gives me the creeps because of the risk of fire.

Aircrete blocks cracking is nothing new! I used to do up to 10 site inspections a week on self-build houses, housing estates and apartment blocks back in the 1980's and 1990's, sometimes the blocks would have serious cracking even before building completion! This is the reason, why I have never specified aircrete, or lightweight blocks on any of my projects! Chartered Architect.

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

Sounds like you should just not use aircrete blocks.

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

we face a problem of general decline...

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

who else is watching this, and then taking the day off ...with a litre of JD......

Uk suffering from this concrete

As a fifty five year old bricklayer this lack of basic knowledge drives me nuts.

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

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

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)

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

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' -

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 KZread

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

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

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.