roof insulation - kingspan solution cost + plastering etc
Discussion
Hello!
how much do you reckon it would cost per sqm to have someone put kingspan type insulation in the roof of my 'mono-storey' 1980s home's roof? (we have no loft we have vaulted ceilings).
currently it's got some oldskool plystryrene stuff that's about half thicknesscovered with sheets of marine ply. i want to take all the existing out and then have kingspan type and then plaster board and then plaster. on this is there any sort of lightweight plaster board? or ideally lightweight insulated board? ought i consult a structural enginneer (i.e weight of plaster board and plaster too much??) - presumably a builder will know if it's okay? oh and that's the final point - would i do this through a general builder or just find a plasterere type?
so that's the roof. the walls are normal cavety wall but 'pioneeringly' have polystyrene type stuff in the walls too (i know know having a new olier and being able to see in the walls!). inside it's a bit 'loft style' with just the blocks painted (it looks kind of cool but we want to make the house more 'smooth' so i am wondering about plasterboard and plaster or some sort of dry lining..any ideas on cost again (per sqm).
live nr MK.
how much do you reckon it would cost per sqm to have someone put kingspan type insulation in the roof of my 'mono-storey' 1980s home's roof? (we have no loft we have vaulted ceilings).
currently it's got some oldskool plystryrene stuff that's about half thicknesscovered with sheets of marine ply. i want to take all the existing out and then have kingspan type and then plaster board and then plaster. on this is there any sort of lightweight plaster board? or ideally lightweight insulated board? ought i consult a structural enginneer (i.e weight of plaster board and plaster too much??) - presumably a builder will know if it's okay? oh and that's the final point - would i do this through a general builder or just find a plasterere type?
so that's the roof. the walls are normal cavety wall but 'pioneeringly' have polystyrene type stuff in the walls too (i know know having a new olier and being able to see in the walls!). inside it's a bit 'loft style' with just the blocks painted (it looks kind of cool but we want to make the house more 'smooth' so i am wondering about plasterboard and plaster or some sort of dry lining..any ideas on cost again (per sqm).
live nr MK.
You need to know a hell of a lot more about the existing roof build up before anybody suggests anything to insulate the roof.
From outside covering to existing inside covering , including any ventilated voids , it is all very important.
Do not let anyone talk you into doing any works untill you have gathered all the info.
From outside covering to existing inside covering , including any ventilated voids , it is all very important.
Do not let anyone talk you into doing any works untill you have gathered all the info.
Busamav said:
You need to know a hell of a lot more about the existing roof build up before anybody suggests anything to insulate the roof.
From outside covering to existing inside covering , including any ventilated voids , it is all very important.
Do not let anyone talk you into doing any works untill you have gathered all the info.
okay dokey then..!From outside covering to existing inside covering , including any ventilated voids , it is all very important.
Do not let anyone talk you into doing any works untill you have gathered all the info.
can you help me a bit though.
basically it all seems to be 'fairly standard' 'modernish build standard'.
so we've got thermolite blocks and clay brick walls.
we've got normal wooden rafters/joists approx 1 foot apart there's then some sort of plastic sheel type waterproofing stuff then felt then normal 80s concrete marley tiles as you'd find on a normal 80s 'exec home'. inside between the rafters there is this polystyrene type insulation held covered by the ply.
based on that what other things do I need to find out about?
and do you think a proper builder is appropriate or as i say do i need some other sort of advice?
I am guessing that plastic sheet may have been a vapour barrier at some time .
It is unlikely that the felt below the roof tiles is a breathable membrane so we have to assume we must cross ventilate the void between the rafters and above the insulation .
Do you have any vents at the eaves ?
The biggest problem you can introduce to your property is condensation by not having a suitable vented void above the new insulation.
To bring the roof insulation up to spec you should be aiming to get say 100mm celotex between the rafters ( with a 50 ventilated gap above ) then a further 50mm below the rafters , then of course your ceiling finish .
It is unlikely that the felt below the roof tiles is a breathable membrane so we have to assume we must cross ventilate the void between the rafters and above the insulation .
Do you have any vents at the eaves ?
The biggest problem you can introduce to your property is condensation by not having a suitable vented void above the new insulation.
To bring the roof insulation up to spec you should be aiming to get say 100mm celotex between the rafters ( with a 50 ventilated gap above ) then a further 50mm below the rafters , then of course your ceiling finish .
Spudler said:
Just get a reputable builder in, its not that big a deal.
I agree it isnt a big deal , but it is very easy to make basic mistakes , any many guys out there are incredibly still making them .I just want the OP to be aware of what the basics are , rather than be diagnosing a problem next year .
Busamav said:
Spudler said:
Just get a reputable builder in, its not that big a deal.
I agree it isnt a big deal , but it is very easy to make basic mistakes , any many guys out there are incredibly still making them .I just want the OP to be aware of what the basics are , rather than be diagnosing a problem next year .
, more a reassurance to the OP.
Busamav said:
Do you have any vents at the eaves ?
yes fecking great big ones - basically depening on where you are in the building it's either a gap beetwen top of wall and the wort of barge board thing that's then dovered in wire mesh - which i am now improving on> i have been making some quite nice 'guards' out of wire mesh to make it more 'vermin proof'. i figured out that a ruddy squirrel had got in last year and also either a bird or a mouse or a bat or something (can bats dig through insulation? anyway something).Busamav said:
To bring the roof insulation up to spec you should be aiming to get say 100mm celotex between the rafters ( with a 50 ventilated gap above ) then a further 50mm below the rafters , then of course your ceiling finish .
okay i think i undertand this. i think i might dismantle mart of the roof someehre to see what equivalent there is to the 50mm vent gap you mention is. might have to leave it a week though cos the wife has people coming over this weekend! Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff