Hi,
I am doing a side extension, the specified joists for the first floor are 200x75 over a 4.2m span, the reg drawings specify joist hangers on both the new extension wall and where they hang from the old external cavity wall..
my problem is that the floor level needs to match the inside and the top of the new joist height would then fall just below mid course on the old cavity wall (as does the bottom of joist, typically ), I was wondering about the following options:
1) cut holes for the joists in the wall and build them in (cons: time consuming, damp issues?, joist movement?)
2) get oversized joist hangers (225m deep) so the joists drop lower (cons:joist not holding the top of the hanger in the wall/ will building inspector like it?)
3) put hangers in course above and notch the bottoms more than the 5mm or so needed to get a level run for the plasterboard (cons:weakens the joist, will building inspector like it?)
other?
I will of course check with the building inspector before doing anything non-standard but wondered if any of you had any suggestions on the best way forwad?
cheers
Trev
I am doing a side extension, the specified joists for the first floor are 200x75 over a 4.2m span, the reg drawings specify joist hangers on both the new extension wall and where they hang from the old external cavity wall..
my problem is that the floor level needs to match the inside and the top of the new joist height would then fall just below mid course on the old cavity wall (as does the bottom of joist, typically ), I was wondering about the following options:
1) cut holes for the joists in the wall and build them in (cons: time consuming, damp issues?, joist movement?)
2) get oversized joist hangers (225m deep) so the joists drop lower (cons:joist not holding the top of the hanger in the wall/ will building inspector like it?)
3) put hangers in course above and notch the bottoms more than the 5mm or so needed to get a level run for the plasterboard (cons:weakens the joist, will building inspector like it?)
other?
I will of course check with the building inspector before doing anything non-standard but wondered if any of you had any suggestions on the best way forwad?
cheers
Trev