Prompted to some extent by the Scottish schools discussion, my thoughts have turned to a wall I need to fix this summer.
It's at the front of the house, at the boundary with the pavement, is about 3 feet high and consists of two leaves: A retaining wall (the driveway is above pavement level) and a facing wall in blue brick. The retaining wall seems sound but a couple of metres of the facing wall has bulged away from it to a significant degree. Although it looks like a Flemish bond pattern, it turns out that what looks like the headers are actually half bricks, so the two leaves aren't tied together. It's probably taken the best part of 150 years to get to this state but since it's in imminent danger of collapse, I need to fix it.
Clearly, the rebuilt structure will need to be tied together, as should the remainder that I don't need to rebuild. The question is, what's the best way to do this? Ideally, I would cut out the retaining wall to take proper headers, but I only have the bricks (and half bricks) that come out of the wall and I suspect that matching replacements will hard to source. Conventional ties are fine for a whole new wall and remedial ties for securing a structure in situ (like the part that doesn't need rebuilding), but this is neither. I had been thinking of adding some masonry screws into the retaining wall to coincide with the mortar layer of the rebuilt leaf (I know these won't last as well as stainless ties would, but should last for quite some time) but maybe someone has a better idea?
I'm also wondering what mortar to use. The original structure was clearly built with a lime mortar, most of which is now gone. I'm guessing I should use lime again, but it seems quite a faff, so I'm wondering if it's necessary on blue bricks and a low wall. Of course, nothing will match the existing unless I re-point the whole wall.
Any thoughts or experiences chaps?