Hi,
Trying to determine whether I should use 6mm or 8mm bars to create a lintel repair above a patio door. I had thought 8mm, but since read that thicker isn't always better for crack stitching because of flexibility.
The house I bought 4 years ago has two cracks at the back, one stepped crack from the kitchen window and another from the patio door. It's a 1930's semi with cavity walls. Windows and doors were replaced circa 15-20 years ago by previous owners and 11 years ago they some remedial wall-tie work done and at some point an attempted repair on the crack above the patio door was done (simply filled the crack in with mortar!). The upper half of walls are rendered in concrete The crack above the kitchen window was under 1mm and the one over the patio door about 3mm.
At the time of purchase the advice was to get it repaired but get further advice from a structural engineer if their was any further movement. The cracks have not changed in 4 years and are only in the outer wall. I have used 6mm helical bar to repair the kitchen window crack a few months ago - two rows of 3m bars 3 courses apart to create a brick lintel and then using 1m bars 6 courses up where the crack extends to. Easier to do the smaller one to practice/fine tune what to do
The patio door is 2.2M wide so going to use 7M bars cut in half. Not sure whether to go for 8mm bars because of the wider opening or simply stick with 6mm - contacted the company who gave me Load tables for the bars, which is only useful if I can work out the load, or if I need to.
Trying to determine whether I should use 6mm or 8mm bars to create a lintel repair above a patio door. I had thought 8mm, but since read that thicker isn't always better for crack stitching because of flexibility.
The house I bought 4 years ago has two cracks at the back, one stepped crack from the kitchen window and another from the patio door. It's a 1930's semi with cavity walls. Windows and doors were replaced circa 15-20 years ago by previous owners and 11 years ago they some remedial wall-tie work done and at some point an attempted repair on the crack above the patio door was done (simply filled the crack in with mortar!). The upper half of walls are rendered in concrete The crack above the kitchen window was under 1mm and the one over the patio door about 3mm.
At the time of purchase the advice was to get it repaired but get further advice from a structural engineer if their was any further movement. The cracks have not changed in 4 years and are only in the outer wall. I have used 6mm helical bar to repair the kitchen window crack a few months ago - two rows of 3m bars 3 courses apart to create a brick lintel and then using 1m bars 6 courses up where the crack extends to. Easier to do the smaller one to practice/fine tune what to do
The patio door is 2.2M wide so going to use 7M bars cut in half. Not sure whether to go for 8mm bars because of the wider opening or simply stick with 6mm - contacted the company who gave me Load tables for the bars, which is only useful if I can work out the load, or if I need to.
