Apologies if I am on the wrong forum but.... I have a cold stairway with a high ceiling. The roof cavity above is hard to access, has some insulation but not much. Hence any heat rises up the stair well to the ceiling, collects and the escapes. Picture included hopefully.
My plan is to fix joist hangers and joists to the internal walls beneath this area, to create a false ceiling with a void in between. I reckon the void can be 20 to 30cm. I would insulate this as much as possible.
I thought I could put something like Kingspan board between the new joists, perhaps some more, thinner Kingspan above, bridging the joists, or roll fibreglass over these. Then put plaster board up and get plasterer in.
I have no experience.
I am struggling with questions: 1) about ventilation – should I completely stuff the void with Rockwool / fibre glass? Do I / don’t I leave an air space. Do I need to put ventilation grills in? Where – original ceiling to roof space or false ceiling to the void or one end of the false ceiling to another or through the external wall, into the newly created void?
2) the new ceiling will be an “L” shape above a stair with a 90 degree corner. It is only about a meter wide and say 3 M long. Andy tips on materials? I am thinking that the joists wont need to be too big or strong – just supporting plaster board and the insulation. What are suggested joist spaces - do they correspond with standard insulation board width?
3) Do I need to add some sort of vapour membrane somewhere.
Thanks in advance.
My plan is to fix joist hangers and joists to the internal walls beneath this area, to create a false ceiling with a void in between. I reckon the void can be 20 to 30cm. I would insulate this as much as possible.
I thought I could put something like Kingspan board between the new joists, perhaps some more, thinner Kingspan above, bridging the joists, or roll fibreglass over these. Then put plaster board up and get plasterer in.
I have no experience.
I am struggling with questions: 1) about ventilation – should I completely stuff the void with Rockwool / fibre glass? Do I / don’t I leave an air space. Do I need to put ventilation grills in? Where – original ceiling to roof space or false ceiling to the void or one end of the false ceiling to another or through the external wall, into the newly created void?
2) the new ceiling will be an “L” shape above a stair with a 90 degree corner. It is only about a meter wide and say 3 M long. Andy tips on materials? I am thinking that the joists wont need to be too big or strong – just supporting plaster board and the insulation. What are suggested joist spaces - do they correspond with standard insulation board width?
3) Do I need to add some sort of vapour membrane somewhere.
Thanks in advance.
