Cracks reappearing in all walls

EachPenny

Apodemus wrote: »

Any “builder” that used expanding foam in my house wouldn’t get asked back!

It's an improvement on rolled up newspaper or scrunched up carrier bags.

I'm not sure there was a justification in the OP's case, but in some situations the use of expanding foam is an entirely appropriate building practice.

Apodemus

EachPenny wrote: »

It's an improvement on rolled up newspaper or scrunched up carrier bags.

I'm not sure there was a justification in the OP's case, but in some situations the use of expanding foam is an entirely appropriate building practice.

Hmmm... rolled up newspaper and carrier bags are at least easily reversible, expanding foam just leaves a mess that can never be cleaned off! Rolled up newspaper, or paper mache can provide an appropriate support for filler and plaster. Just because something comes in a can and costs more, doesn’t mean it’s better!

Santosda

There were no cracks before starting the repair work but came later. But I got the outer cracks repointed.

Santosda

I feel the same. My gut feeling says the foam is causing reappearance of cracks. But in not expert.

stuart45

Thermalite blocks are well known for suffering from shrinkage cracking, which is why some builders are using concrete blocks for the inner skin. It is worse when wet blocks in the winter are used and they crack as they dry out.
Normally the cracking occurs quite early in the life of the house, but sometimes when a new occupent heats the house at a higher temperature for longer periods than the previos ones the cracks can appear. It often happens above the frames which is a weak spot in the wall.

EachPenny

Apodemus wrote: »

Hmmm... rolled up newspaper and carrier bags are at least easily reversible, expanding foam just leaves a mess that can never be cleaned off!

I've found this stuff works quite nicely if it is really necessary to remove it:-
https://www.everbuild.co.uk/product/foam-eater/

Apodemus wrote: »

Rolled up newspaper, or paper mache can provide an appropriate support for filler and plaster. Just because something comes in a can and costs more, doesn’t mean it’s better!

True, but if I'm paying a builder ££££'s per hour (I wouldn't if I could avoid it) then I'd prefer them to use something that costs a bit of money but takes seconds to use and minutes to set, rather than have them spending hours worth of ££££'s making paper mache and waiting for it to dry. I'd also want them to consider the risks of vermin eating the paper (vs PU foam = less tasty) as well as any potential issues with needing the material to retain some (but not too much) flexibility when set.

Something else to consider would be the fire performance - paper is not good, but then PU foam also has some alarming qualities in fire. I can see (post-Grenfell) a time when non-fire rated expanding foam is banned.

EachPenny

Santosda wrote: »

There were no cracks before starting the repair work but came later. But I got the outer cracks repointed.

Santosda wrote: »

I feel the same. My gut feeling says the foam is causing reappearance of cracks. But in not expert.

The foam isn't going to be the original cause of the cracking, but if used as a filler along the lines of existing cracks will help ensure new cracks form in the same location.

Foam is a flexible filler which means that movement either side will result in the foam being stretched or compressed. Plaster is not flexible, and if bridging over foam which is being subjected to movement, the plaster will crack, most likely where the foam is.

Can you describe more clearly how the builder used the foam? Was it along the cracks, or to fill other gaps? Did they dig out parts of the wall (chase) before filling these with foam?

Also are the walls involved quite long, or relatively short, or a mixture?

Santosda

PLease can anyone help me to upload the photos for clear understanding for you guys.. I tried but not working out. which website I have to upload the photos to?
Thanks

Head_The_Ball

I use this site.

https://postimages.org/

Upload your picture or pictures, copy the Hotlink for forums and paste it here.

As you are a new user you will need to break up the link. Someone will fix it for you.

Change https://......to ht tps://...........

Santosda

ht tps://postimg.cc/1fgZ8xkT