joining an old wall to a new wall....

[jason61c]

Strange one this, the upstairs of my house is about 200 years old. I've a few issues that i'm sorting out fixing old movement cracks in the lower cob walls of the first floor and rotten lintels that have caused some bulging in the middle of the wall. We're casting a lintel in situ and joining it to the outer brick arch of the window and the first floor joists so it should never move again.

As the lower is 800mm thick, the top is 9 inch brick, I've spare 'wall to play with'. To help stop any future movement and give strength to the upper my builder has suggested building an inner wall of thermalite blocks(on their side) so 9inch also next to the old wall(first floor). As we go fill any gaps with a runny lime mortar mix and fit a few hundred helifix type things.

We've come up with this plan between us. Does it seem to make sense? anyone done similar?

 

[noseall]

Using a new wall to fix an unstable existing wall is nothing unusual. However, you are building up off the old existing wall below, correct?

 

[jason61c]

Using a new wall to fix an unstable existing wall is nothing unusual. However, you are building up off the old existing wall below, correct?

Yes, the wall below is a 700mm ish thick cob wall, where currently the upstairs is 9inch brick on the outside edge so there's plenty of strong wall below for it to sit on.