Part of my residential conversion of an industrial building involves cutting some windows in the front wall
The wall construction is engineering brick inner, stone outer, coursed but with random heights, something like this:
There;s no cavity per se, the brick is like English garden wall bond and the header row is mortared to the stone, with extra bits of stone rubble thrown into what would have been a cavity
I need to cut up to about 400mm away from the top of the stone wall, and put a slight arch on, but the planning have insisted I don't use any dressing like a lintel, or stones running in a curve as one might expect an arch to be formed, with a keystone etc. It has to look just like an arch shape was cut into the straight layers of stone, so i'll need some support for it
The stone leaf is about 300mm thick, the brick is about 200mm thick (on average). The windows must be recessed 150mm
I could use a curved lintel, or even just a bit of suitably thick bent steel (the load isn't significant).. Should I try and fit it without removing the stones (I.e. cut a groove in the stone, fit the steel, then cut the arch after it's all set)? or should I remove all the stones, number them as they come out and put them back in the same place (shaped with an angle grinder to fit the curve of the steel) - this might end up leaving part of the lintel on show, even if I recess it into the underside of the arch. Maybe the steel could be set into the stone further up than the underside of the arch, leaving the stone to wrap around the arch edge.
I could maybe tack mesh to the back of the stone and render it up or make a formwork and vibrate some concrete in. Coupled with the window frames being aluminium and arched at the top I think there'd be suitable support.
I could perhaps form a concrete lintel (the span is only 1.2m) and install it, or better, take the stones out and form them into the concrete as it's setting
I could just fit a stone lintel (I have some colour-suitable from elsewhere in the building) and see if anyone notices
All these seem less than ideal in some mix of terms of time, effort, cold bridging, aesthetic, legal repercussions etc
can anyone think of any better options?
Thanks
The wall construction is engineering brick inner, stone outer, coursed but with random heights, something like this:
There;s no cavity per se, the brick is like English garden wall bond and the header row is mortared to the stone, with extra bits of stone rubble thrown into what would have been a cavity
I need to cut up to about 400mm away from the top of the stone wall, and put a slight arch on, but the planning have insisted I don't use any dressing like a lintel, or stones running in a curve as one might expect an arch to be formed, with a keystone etc. It has to look just like an arch shape was cut into the straight layers of stone, so i'll need some support for it
The stone leaf is about 300mm thick, the brick is about 200mm thick (on average). The windows must be recessed 150mm
I could use a curved lintel, or even just a bit of suitably thick bent steel (the load isn't significant).. Should I try and fit it without removing the stones (I.e. cut a groove in the stone, fit the steel, then cut the arch after it's all set)? or should I remove all the stones, number them as they come out and put them back in the same place (shaped with an angle grinder to fit the curve of the steel) - this might end up leaving part of the lintel on show, even if I recess it into the underside of the arch. Maybe the steel could be set into the stone further up than the underside of the arch, leaving the stone to wrap around the arch edge.
I could maybe tack mesh to the back of the stone and render it up or make a formwork and vibrate some concrete in. Coupled with the window frames being aluminium and arched at the top I think there'd be suitable support.
I could perhaps form a concrete lintel (the span is only 1.2m) and install it, or better, take the stones out and form them into the concrete as it's setting
I could just fit a stone lintel (I have some colour-suitable from elsewhere in the building) and see if anyone notices
All these seem less than ideal in some mix of terms of time, effort, cold bridging, aesthetic, legal repercussions etc
can anyone think of any better options?
Thanks