I am trying to do a structural repair to a brick wall that has some large gaps – 1-3" between some of the bricks due to some foundation movement over the last 300 years. The gaps are essentially vertical cracks where the mortar has broken loose and the bricks are separating. I know that any foundation movement will cause more cracks but I want to at least stabilize the cracks so that the wall does not collapse. I am thinking that a mixture of something like sand or pea gravel and a strong adhesive will provide the support I need. I have tried Gorilla glue in matrix material but the foaming and expansion just doesn't work well. I think a tube adhesive with a high tensile strength will work, I just have little experience with the new ones out there.
Any ideas or suggestions are appreciated. I always do a "proof of concept" before going full scale so I can try several ideas.
Best Answer
Three inch gaps seem quite large - even for a 300 year old wall.
You just need to use a good mortar mix (sand and cement) on the narrower gaps.
Clean out all the old, lose material first to make sure that you get good adhesion and then push the mortar right into the gaps as far as it will go. Work on a small area (1 m2) at a time.
Adding pea gravel to give the mix more "body" might work on the wider ones.
However, I'd get a professional to have a look at the wall first to make sure you're not going to have to redo this work in a couple of years time. If the foundations have gone it might need something more substantial work doing.
Is the wall part of a house or just a garden wall? If it's the latter then dismantling and rebuilding might be the best long term option.