The semi-detached house we recently bought had a loft bedroom conversion done around 1987 by a company called Econoloft. They have hung the floor joists from two RSJ's spanning the room on either side, and made the floor on 18mm chipboard, then built the stud walls on top.
at the gable end, the chimney runs up one corner of the wall and is stepped about .5 metre above the floor - going from approx 400mm to approx 200mm protrusion from the wall; the stud wall at this end stands about another 200mm clear of the widest part of the chimney.
I am going to have a window installed in the gable end to give some more light into the room, and as it's going to be a music room, i would prefer to have the shelving for speakers/hifi on the solid wall instead of the suspended floor - to keep the wife happy
My plan is to take the stud wall down, and batten the wall and screw new plasterboard to this. I've spoken to the local building control office, and while i need to apply for notice for the window as it will require an opening in the gable end, as it will only be a small window, non opening and obfuscated (and approx 5m from the boundary), they don't require anything else. They also said as the stud wall does not affect the staircase/stairwell of the room, and is non load bearing, they aren't interested in me moving the stud.
The question i have is thus; the existing stud uses foil backed 9.5mm plasterboard with rockwool insulation between the studs, and strips of plasterboard on the back to hold the rockwool in place (NOT complete boards, just wide "batons" of board); the ceiling is the same. if the wall is now going to be directly against the external cavity wall, can i just use the rockwool between the studs fixed to the wall and board back over, or do i need to use something else instead? Also, the chimney stack has been (very) roughly covered with some sort of render up to approx 3/4 way up; I was thinking of either tidying the rendering up and leaving the chimney as a direct mortar rendered wall, or either D&D some board on it, or build a stud round it to board on. is there any issue with doing this round the chimney?
Also, the floor joists are 7"x2" and the last one is approx. 350mm from the wall; my thinking is to add a 7x2 and fix to the cavity wall with expanding studs to hold the extra piece of board it will now need at the end; that area is going to be behind wall mounted shelving so unlikely to have any weight; is this acceptable? I would hang from the RSJ, but the wooden joists bolted to the RSJ that the floor joist hangers are one end too soon!
My final question is about the floor joists. i've looked at the orginal plans, and the joists are shown as direct cross room joists, hung from the joist affixed to said RSJs; however the immersion heater cupboard is roughly one third into the room in the middle - so pipework ran from the far corner of the loft into the middle and dropped down. instead of rerouting the pipes (most of which are now gone), they have created a weird "lattice" of three of the joists, running diagonally along with the pipes; they are then hung onto a long cross joist which caps off 3 and is secured at either end to normal joists, which the diagonal beams being hung at an angle against other beams. the floor does bounce, but no more than i would expect in approx 4m wide room. Is this a safe way to have it, or should i look at replacing these diagonal joists with straight across beams instead?
Many thanks in advance - and sorry for all the questions! I'm used to tackling work myself, but not until i know exactly what i need to do and be aware of!
at the gable end, the chimney runs up one corner of the wall and is stepped about .5 metre above the floor - going from approx 400mm to approx 200mm protrusion from the wall; the stud wall at this end stands about another 200mm clear of the widest part of the chimney.
I am going to have a window installed in the gable end to give some more light into the room, and as it's going to be a music room, i would prefer to have the shelving for speakers/hifi on the solid wall instead of the suspended floor - to keep the wife happy
My plan is to take the stud wall down, and batten the wall and screw new plasterboard to this. I've spoken to the local building control office, and while i need to apply for notice for the window as it will require an opening in the gable end, as it will only be a small window, non opening and obfuscated (and approx 5m from the boundary), they don't require anything else. They also said as the stud wall does not affect the staircase/stairwell of the room, and is non load bearing, they aren't interested in me moving the stud.
The question i have is thus; the existing stud uses foil backed 9.5mm plasterboard with rockwool insulation between the studs, and strips of plasterboard on the back to hold the rockwool in place (NOT complete boards, just wide "batons" of board); the ceiling is the same. if the wall is now going to be directly against the external cavity wall, can i just use the rockwool between the studs fixed to the wall and board back over, or do i need to use something else instead? Also, the chimney stack has been (very) roughly covered with some sort of render up to approx 3/4 way up; I was thinking of either tidying the rendering up and leaving the chimney as a direct mortar rendered wall, or either D&D some board on it, or build a stud round it to board on. is there any issue with doing this round the chimney?
Also, the floor joists are 7"x2" and the last one is approx. 350mm from the wall; my thinking is to add a 7x2 and fix to the cavity wall with expanding studs to hold the extra piece of board it will now need at the end; that area is going to be behind wall mounted shelving so unlikely to have any weight; is this acceptable? I would hang from the RSJ, but the wooden joists bolted to the RSJ that the floor joist hangers are one end too soon!
My final question is about the floor joists. i've looked at the orginal plans, and the joists are shown as direct cross room joists, hung from the joist affixed to said RSJs; however the immersion heater cupboard is roughly one third into the room in the middle - so pipework ran from the far corner of the loft into the middle and dropped down. instead of rerouting the pipes (most of which are now gone), they have created a weird "lattice" of three of the joists, running diagonally along with the pipes; they are then hung onto a long cross joist which caps off 3 and is secured at either end to normal joists, which the diagonal beams being hung at an angle against other beams. the floor does bounce, but no more than i would expect in approx 4m wide room. Is this a safe way to have it, or should i look at replacing these diagonal joists with straight across beams instead?
Many thanks in advance - and sorry for all the questions! I'm used to tackling work myself, but not until i know exactly what i need to do and be aware of!
