My previous house was Victorian and built on clay, foundations almost non existant. But as you say lime mortar allows movement, additionally I found that the mortar had very coarse locally dug sand in it, with gravel up to about 5mm. I think those rounded stones acted like ball bearings!
Great subject!!! My house too, old 40's has a crack in the front elevation, not concerned in the slightest, there not going to part company, its not moved since I was aware of it....don't panic, don't panic.
This makes sense Woger thanks. My house built in 1851 rat trap bond with lime. Stone cellar foundation. Width of the stone foundation walls are about 1ft wide! But 7ft deep. Still standing. Same happens as you say here.
Brilliant and succinct assessment. Had the same problem on just the south facing side of house. The highly experienced structural engineer's assessment was the same as the structural repairer's in that the mortar (cement) was mixed way too strong and I'm well past the original 10 year new house warranty. There should be standards for the cement mix when they build new houses.
Lovely topical back drop, a beautiful old brick kiln. Right go get yourself a cup of tea, a Rant is about to start. I am a 58 year old bricklayer, so I was taught by men who were taught by men who built rows and rows of terrace house in lime/sand mortar. Think of Coronation Street Victorian houses. You may have twenty terrace house, not a crack in sight. Now on site we have expansion joints on detached houses, sometimes 18" from a corner. Why? Somewhere in building history of the 20th Century, some college boy read a book and learned that the more cement in mortar, the stronger it is. Now in theory, this is correct, in a crush test, it will be stronger. Now for the classic, "A little knowledge is dangerous." Firstly as you stated, the mortar should never be stronger than the brick. Mortar isn't there to stick bricks together, it is there to hold bricks apart. Going back to our college boy, this ideology of stronger is better is at the heart of a lot of cracking brickwork. Cracks started to become common when the mixes started getting stronger. I have heard guys disguising 3 and 1 on normal brickwork. Madness. I was taught 4 and 1 is the strongest and this was only to be used for engineering bricks. 5 or 6 to 1 is fine. So as the mortar became stronger, cracks became more common, so the college boys, instead of asking the tradesmen, went back to the books that told them that a more cement equals stronger, so they specified a stronger mix. Face slap time. Obviously this didn't work so they started to introduce all these bloody expansion joints, (this is a whole other rant about the weakness these things cause to brickwork.) Now on top of an over strong mix and expansion joints, we are being told to put stainless steel bars into the mortar. The mortar is the expansion joint. Go back to our 20 terrace houses, see any expansion joints? Rant over.
I've got one of these 1930s houses built on clay that likes to go up and down, pebble dashed on the top and exposed red brick at the bottom. I've got step cracking that is showing through the pebble dash finish. Am I wasting my time if I have it rerendered? Or is there a render mix that is forgiving?
Unusual place to crack that, settlement cracks usually appear over doorways and windows. Check down the side to see if there’s any bowing in the gable end and sagging in the roof? To rule out the roof splaying pushing the walls out or even failed wall ties? Or it could be just the bricks were wet when laid and have shrunk when dried out. Still say that’s more likely to appear over doors and windows though.
Roger got it wrong initially talking about settlement on clay foundation as that pattern of cracking shows the movement is horizontal and not vertical. Hexeventually got on to the correct reason which is mortar being much stronger than the bricks. It's cracking due to expansion and contraction throughout the day. As Roger says, replace the cracked bricks and repoint the cracked joints in a soft mortar (1:2:9, cement:lime:sand).
@@johncranna No, I don’t think the strength of mortar is much of an issue. There’s only two bricks cracked, the rest is cracked along the joints. Indicating only a slightly stronger mix than the bricks or those two bricks already had defects (airline cracks) when they were laid. I stand by my first assessment I.E lateral movement or shrinkage from the materials drying out after being laid.
@leeboss373 so we agree that it's due to lateral movement. But just to clarify your assessment, clay bricks don't shrink - they expand. Concrete blocks shrink if they are laid soon after manufacture. As I said, the lateral movement of the wall is due to the expansion and contraction as it heats up and then cools down. As it cools down, the wall goes into tension and is likely to crack. If the mortar was weaker then this tension could be spread about the mortar joints with micro cracking but as it is stronger then the cracking is concentrated in one vertical position and has effectively formed its own movement joint.
@@johncranna Well, I ruled out expansion and contraction because that would likely show on the DPC more than anywhere else but I’ve just thought that as we can’t see what is next to the property, it’s possible that there’s a house nextdoor that shields the lower part of the wall from exposure to the sun. So in that case it’s possible that it could be expansion and contraction. But yes definitely lateral movement.
@@TurinTuramber thanks for response. Makes sense we had loft floor board put in and thats when i noticed it. May be all the work has caused some joist pressure points. By the way loft is for storage only. Just thinking if i should be worried.
@@shafserious2805If just a few mm wide then they will just be superofficial cracks in the plaster. Try to spread the load out in the loft and once you decorate you can fill them in. Installing floor boards would have pulled the ceiling frame about a bit, nothing to worry about.
Love the Skill Builder channel so I hate to say this but I disagree with Roger’s assessment. The brickwork to the right of the crack looks like different mortar and joint size. I think the corner was toothed as it was built and then when the side of the house was run in perhaps days later with different mortar the bricklayers didn’t do a good job of filling the joints and then over time with water penetration and the freeze thaw cycle it found the weak spot in the wall. Toothing brickwork is bad practice in my book but I’m sure it happens on big sites. Keep up the good work!! Whatever happened to the movement to stop van theft?
Opened up a window some years ago in my Brick wall. Every 30 cm there are 4 solid steel wires. It was very hard to break the brick up. My house is from 1984. Don’t see the wall coming down this century. Jeje.
That looks like some toothing . The mortar on the left is a different colour than the right . It could be an extension that is moving . Deffo 2 colours of gobble though 🧐🧱👍🏽
I've got some cracks in my concrete block house but i think its Because i live a mile from a Quarry and they blast every few months and you can feel the vibrations through the house
You don't need to replace the brick you can get some brick dust and mix it in with a bit of more PVA glue and force into the crack you know about forcing into cracks don't you skill builder😮
@@lksf9820 don't know what you mean black line?? yes if the colours not the same you could use some powdered paint if you wanted to get the colour you don't need brick dust. It's got to be less noticeable than seeing a crack is my point, and could be completely invisible.
@@SkillBuilder looks like they are now turning there attention to wood burners now the next huge threat to health. Apparently a wood burner can give u dementia🙄🙄if that was the case the whole of Victorian England would have had dementia 😊
Looks like a settlement induced crack/failure. Not too much to get concerned about , if it were rotational, that’s a different matter. But as Roger states if the mortar wasn’t so cement rich, ie if it was a lime mortar or even a gauged lime mortar the cracking would not occurin the brick, it would travel thru the beds & perpinds & also the great advantage of a lime rich mortar is that it can self heal. Another overlooked plus is that walls constructed with lime mortar breath & very effectively, I can remember a perfect example of this we were called into look at a job which entailed removing the existing cement mortar, the stone in that area was saturated, the next day, the stone was “dry”. We also worked on a very old random rubble wall built in the 1600’s, it had been rendered which of course had failed, the whole wall, some 50 to 60 yds was absolutely saturated once all the render was removed & the gauged lime mortar pointing was completed you wud not have believed it was the same wall, but guess what, we were never paid the final payment, which if my memory is correct was around £7000, charming working in the UK. Not, that’s why we started up in Texas, a World of a difference, remember you have the ultimate persuader there. 😂. Yes we carry in Texas. All legit,
Roger got it wrong initially talking about settlement on clay foundation as that pattern of cracking shows the movement is horizontal and not vertical. Hexeventually got on to the correct reason which is mortar being much stronger than the bricks. It's cracking due to expansion and contraction throughout the day. As Roger says, replace the cracked bricks and repoint the cracked joints in a soft mortar (1:2:9, cement:lime:sand).
Perhaps the wall cracked up when it heard one of Rodgers puns😂😂.
cracking video Roger !
My previous house was Victorian and built on clay, foundations almost non existant. But as you say lime mortar allows movement, additionally I found that the mortar had very coarse locally dug sand in it, with gravel up to about 5mm. I think those rounded stones acted like ball bearings!
Great subject!!!
My house too, old 40's has a crack in the front elevation, not concerned in the slightest, there not going to part company, its not moved since I was aware of it....don't panic, don't panic.
This makes sense Woger thanks. My house built in 1851 rat trap bond with lime. Stone cellar foundation. Width of the stone foundation walls are about 1ft wide! But 7ft deep. Still standing. Same happens as you say here.
Brilliant and succinct assessment. Had the same problem on just the south facing side of house. The highly experienced structural engineer's assessment was the same as the structural repairer's in that the mortar (cement) was mixed way too strong and I'm well past the original 10 year new house warranty. There should be standards for the cement mix when they build new houses.
Lovely topical back drop, a beautiful old brick kiln.
Right go get yourself a cup of tea, a Rant is about to start.
I am a 58 year old bricklayer, so I was taught by men who were taught by men who built rows and rows of terrace house in lime/sand mortar.
Think of Coronation Street Victorian houses. You may have twenty terrace house, not a crack in sight.
Now on site we have expansion joints on detached houses, sometimes 18" from a corner.
Why?
Somewhere in building history of the 20th Century, some college boy read a book and learned that the more cement in mortar, the stronger it is.
Now in theory, this is correct, in a crush test, it will be stronger.
Now for the classic, "A little knowledge is dangerous."
Firstly as you stated, the mortar should never be stronger than the brick.
Mortar isn't there to stick bricks together, it is there to hold bricks apart.
Going back to our college boy, this ideology of stronger is better is at the heart of a lot of cracking brickwork.
Cracks started to become common when the mixes started getting stronger. I have heard guys disguising 3 and 1 on normal brickwork. Madness. I was taught 4 and 1 is the strongest and this was only to be used for engineering bricks.
5 or 6 to 1 is fine.
So as the mortar became stronger, cracks became more common, so the college boys, instead of asking the tradesmen, went back to the books that told them that a more cement equals stronger, so they specified a stronger mix. Face slap time.
Obviously this didn't work so they started to introduce all these bloody expansion joints, (this is a whole other rant about the weakness these things cause to brickwork.)
Now on top of an over strong mix and expansion joints, we are being told to put stainless steel bars into the mortar.
The mortar is the expansion joint. Go back to our 20 terrace houses, see any expansion joints?
Rant over.
Cheers for this, very intresting
I've got one of these 1930s houses built on clay that likes to go up and down, pebble dashed on the top and exposed red brick at the bottom. I've got step cracking that is showing through the pebble dash finish. Am I wasting my time if I have it rerendered? Or is there a render mix that is forgiving?
sand and lime render is more forgiving but it depends on how much movement there is. The crack might not have shown if the render was more forgiving
Great craic
Unusual place to crack that, settlement cracks usually appear over doorways and windows.
Check down the side to see if there’s any bowing in the gable end and sagging in the roof? To rule out the roof splaying pushing the walls out or even failed wall ties? Or it could be just the bricks were wet when laid and have shrunk when dried out. Still say that’s more likely to appear over doors and windows though.
Roger got it wrong initially talking about settlement on clay foundation as that pattern of cracking shows the movement is horizontal and not vertical. Hexeventually got on to the correct reason which is mortar being much stronger than the bricks. It's cracking due to expansion and contraction throughout the day. As Roger says, replace the cracked bricks and repoint the cracked joints in a soft mortar (1:2:9, cement:lime:sand).
@@johncranna
No, I don’t think the strength of mortar is much of an issue. There’s only two bricks cracked, the rest is cracked along the joints. Indicating only a slightly stronger mix than the bricks or those two bricks already had defects (airline cracks) when they were laid.
I stand by my first assessment I.E lateral movement or shrinkage from the materials drying out after being laid.
@leeboss373 so we agree that it's due to lateral movement. But just to clarify your assessment, clay bricks don't shrink - they expand. Concrete blocks shrink if they are laid soon after manufacture. As I said, the lateral movement of the wall is due to the expansion and contraction as it heats up and then cools down. As it cools down, the wall goes into tension and is likely to crack. If the mortar was weaker then this tension could be spread about the mortar joints with micro cracking but as it is stronger then the cracking is concentrated in one vertical position and has effectively formed its own movement joint.
@@johncranna
Well, I ruled out expansion and contraction because that would likely show on the DPC more than anywhere else but I’ve just thought that as we can’t see what is next to the property, it’s possible that there’s a house nextdoor that shields the lower part of the wall from exposure to the sun. So in that case it’s possible that it could be expansion and contraction. But yes definitely lateral movement.
Love this kind of video, thanks Roger
Please do a video on bedroom ceiling cracks
Surely just from people walking around in the loft without creeper boards / flooring, probably on truss cut roof.
@@TurinTuramber thanks for response. Makes sense we had loft floor board put in and thats when i noticed it. May be all the work has caused some joist pressure points. By the way loft is for storage only. Just thinking if i should be worried.
@@shafserious2805If just a few mm wide then they will just be superofficial cracks in the plaster. Try to spread the load out in the loft and once you decorate you can fill them in. Installing floor boards would have pulled the ceiling frame about a bit, nothing to worry about.
Timber drying out in the winter. It’s why cornice was invented
Thank you, that’s exactly what I have
Love the Skill Builder channel so I hate to say this but I disagree with Roger’s assessment. The brickwork to the right of the crack looks like different mortar and joint size. I think the corner was toothed as it was built and then when the side of the house was run in perhaps days later with different mortar the bricklayers didn’t do a good job of filling the joints and then over time with water penetration and the freeze thaw cycle it found the weak spot in the wall. Toothing brickwork is bad practice in my book but I’m sure it happens on big sites. Keep up the good work!! Whatever happened to the movement to stop van theft?
Opened up a window some years ago in my Brick wall. Every 30 cm there are 4 solid steel wires. It was very hard to break the brick up. My house is from 1984. Don’t see the wall coming down this century. Jeje.
That looks like some toothing . The mortar on the left is a different colour than the right .
It could be an extension that is moving .
Deffo 2 colours of gobble though 🧐🧱👍🏽
You can't beat a good gobble.
I've got some cracks in my concrete block house but i think its Because i live a mile from a Quarry and they blast every few months and you can feel the vibrations through the house
Thanks voiceover! That's a great idea, we've had all sorts of extensions on here, how about a *Doomsday Bunker build series* ?
Should really mention that it can be caused by the brick ties between the skins corroding and the walls separating. That's a bit more serious
No. That creates horizontal cracks at about 450 mm centres vertically.
Good ending, bravo...
Hi , could I send you some cracks in brick work for you option ?
One of a small development down the road from us has a wonky downspout, that'd drive me crazy. In fact it does, and I didn't even buy it!
Must have an air source heat pump fitted!!!
The photos arent very good but looks like thermal cracking to me, lack of movement joints in that wall, possibly
Was that a dear old friend Alan Partridge closing up the show?
Underground bunker! Let’s not joke Woge!!
A lot of bricks laid the wrong way up
You don't need to replace the brick you can get some brick dust and mix it in with a bit of more PVA glue and force into the crack you know about forcing into cracks don't you skill builder😮
That'll set leaving a black line.
@@lksf9820 don't know what you mean black line?? yes if the colours not the same you could use some powdered paint if you wanted to get the colour you don't need brick dust. It's got to be less noticeable than seeing a crack is my point, and could be completely invisible.
State of that pointing….😂😂😂
RODGER THAT 👍
Greta T.
dont think its a case of just replacing the bricks ,worth a try and keep an eye on it ,but think it needs a dig round the footings in that area
When footings settle and brickwork doesn't have a movement joint then it will make its own one.
whats the crack 😁
Can we acknowledge how horrible those mortar joints area please!?!?
go on then
👍
Your cracking up Rog , six of sand ,one of cement, one of lime , that's the way ah ha ha ha i like it ah hah ah ha. Remember that tune .
Have a look at the instruction on the cement manufacturer's data sheets.
Not sure of this voice over. Bit down beat.
END OF THE WORLD??!! I'm off to stock up on toilet roll! 🏃♂🧻🧻🧻🧻🧻🧻
Those are crap bricks by the way, slightly harder than a weetabix.should have used proper lime mortar that moves with the temperature
Must be climate change 🤣
😂
Climate change multiplied by Brexit
Acid Rain 🤡
You're right. Someone once told me that polonged hot, dry weather makes the actual ground 'contract' and damage buildings. 😂
I blame the EU.
The Guardian reckons its Brexit ...
Another change on heat pumps coming from the government today 🙄🙄🙄
We predicted this last year but it has taken them a long time to see sense.
@@SkillBuilder looks like they are now turning there attention to wood burners now the next huge threat to health. Apparently a wood burner can give u dementia🙄🙄if that was the case the whole of Victorian England would have had dementia 😊
You need a heat pump mate.
😂
Looks like a settlement induced crack/failure. Not too much to get concerned about , if it were rotational, that’s a different matter.
But as Roger states if the mortar wasn’t so cement rich, ie if it was a lime mortar or even a gauged lime mortar the cracking would not occurin the brick, it would travel thru the beds & perpinds & also the great advantage of a lime rich mortar is that it can self heal. Another overlooked plus is that walls constructed with lime mortar breath & very effectively, I can remember a perfect example of this we were called into look at a job which entailed removing the existing cement mortar, the stone in that area was saturated, the next day, the stone was “dry”. We also worked on a very old random rubble wall built in the 1600’s, it had been rendered which of course had failed, the whole wall, some 50 to 60 yds was absolutely saturated once all the render was removed & the gauged lime mortar pointing was completed you wud not have believed it was the same wall, but guess what, we were never paid the final payment, which if my memory is correct was around £7000, charming working in the UK. Not, that’s why we started up in Texas, a World of a difference, remember you have the ultimate persuader there. 😂. Yes we carry in Texas. All legit,
Roger got it wrong initially talking about settlement on clay foundation as that pattern of cracking shows the movement is horizontal and not vertical. Hexeventually got on to the correct reason which is mortar being much stronger than the bricks. It's cracking due to expansion and contraction throughout the day. As Roger says, replace the cracked bricks and repoint the cracked joints in a soft mortar (1:2:9, cement:lime:sand).