Sealant, vertical gap between widths of brickwork?
- Thread starter pe2dave
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pe2dave
Established Member
I was surprised when I dug out the existing stuff to find just this in the gap! Expanded foam!
This is 10mm - the gap is closer to 18! Shoddy bricky?
RogerS
Established Member
Burnt sand mastic is traditionally used when the rest of the brickwork has been done with lime mortar.
Are you saying the gap has opened by 8mm? If that is the case you need to look closely at why.
pe2dave
Established Member
No, Always was 20mm
Lons
Established Member
Nothing to do with being brittle, if you read earlier posts or search on line you'll find why they expand and in what circumstances expansion joints should be provided.
Jameshow
Established Member
I kno
I know the reasons why but was surprised on a run the brick work which wasn't particularly long. Older brick houses don't tend to have them? Perhaps the foundations aren't stable in which case the should have used a slab. My last extension had a longer run of brickwork and no expansion joint.
Lons
Established Member
Nothing to do with the foundations James, if the founds aren't stable they shouldn't be built on in the first place though that said there will always be movement in founds which is a different thing to stability even though that sounds like a contradiction.
I won't go into detail as there is plenty of info out there for anyone who is interested enough to search for it. There are several reasons some of which are , modern brick manufacturing where the bricks can be from factory on to building sites within weeks or days, bricks can keep expanding for a long time after manufacture. Cavity wall construction, timber or steel framed etc. where the outer leaf is really a brick veneer rather than the old solid walls where there was more support and various brick bonds used but perhaps the most important factor was the introduction of Portland cement in the 1930s where previously lime mortar was used. The latter is far more flexible and to an extent self healing so it could accommodate expansion to a degree. Damned unpleasant stuff to use especially if it's a bit breezy.
I used to have a building company and am no expert on bricks but my brother is, he has a doctorate in construction, concrete and materials, spent his summer and Easter holidays working with me when not lecturing and was a pita as he threw more brick away than he laid because they had minor defects.
Cost me a bloody fortune in expensive hardcore.
Forgot to add that 8m is shorter than normal which is around 10 - 12m so I suspect the bricks were likely calcium silicate type but that's an educated guess.
I won't go into detail as there is plenty of info out there for anyone who is interested enough to search for it. There are several reasons some of which are , modern brick manufacturing where the bricks can be from factory on to building sites within weeks or days, bricks can keep expanding for a long time after manufacture. Cavity wall construction, timber or steel framed etc. where the outer leaf is really a brick veneer rather than the old solid walls where there was more support and various brick bonds used but perhaps the most important factor was the introduction of Portland cement in the 1930s where previously lime mortar was used. The latter is far more flexible and to an extent self healing so it could accommodate expansion to a degree. Damned unpleasant stuff to use especially if it's a bit breezy.
I used to have a building company and am no expert on bricks but my brother is, he has a doctorate in construction, concrete and materials, spent his summer and Easter holidays working with me when not lecturing and was a pita as he threw more brick away than he laid because they had minor defects.
Cost me a bloody fortune in expensive hardcore.Forgot to add that 8m is shorter than normal which is around 10 - 12m so I suspect the bricks were likely calcium silicate type but that's an educated guess.
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Jameshow
Established Member
Thanks for the into.Nothing to do with the foundations James, if the founds aren't stable they shouldn't be built on in the first place though that said there will always be movement in founds which is a different thing to stability even though that sounds like a contradiction.
I won't go into detail as there is plenty of info out there for anyone who is interested enough to search for it. There are several reasons some of which are , modern brick manufacturing where the bricks can be from factory on to building sites within weeks or days, bricks can keep expanding for a long time after manufacture. Cavity wall construction, timber or steel framed etc. where the outer leaf is really a brick veneer rather than the old solid walls where there was more support and various brick bonds used but perhaps the most important factor was the introduction of Portland cement in the 1930s where previously lime mortar was used. The latter is far more flexible and to an extent self healing so it could accommodate expansion to a degree. Damned unpleasant stuff to use especially if it's a bit breezy.
I used to have a building company and am no expert on bricks but my brother is, he has a doctorate in construction, concrete and materials, spent his summer and Easter holidays working with me when not lecturing and was a pita as he threw more brick away than he laid because they had minor defects.
Forgot to add that 8m is shorter than normal which is around 10 - 12m so I suspect the bricks were likely calcium silicate type but that's an educated guess.
I wouldn't be surprised if timber frame.
Expansion joints are necessary due to differential expansion between different materials and construction methods, the introduction of more efficient heating meant the temperature difference between the inside and outside of buildings also has an effect, garden walls are a different matter altogether. I have a 20M garden wall that now has two significant expansion joints 
covered over with some nice hanging baskets, fuchsias seem to like it there. 
covered over with some nice hanging baskets, fuchsias seem to like it there. Just to give an idea of the imposed expansion joint in my garden wall, every second joint down from the top has SS reinforcing bars resined into the stretcher joint across the crack, sorry expansion joint.
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