Flat roof on single storey extension has no insulation

[0Floz0]

Hi,

I've just had a steel put in to remove a pier between the kitchen and a single storey extension. I've been in the property a year and always thought the kitchen got far too cold. Turns out, its because there is no insulation in the flat roof on the extension. This was all signed off with building regulations back in about 2002 so no idea how they got that through. Is this something I can raise with them as a complaint given it was signed off by them? Would that lead to anything?

The more pressing part is what to do with it. I'm refurbishing to sell it on so cost is a factor, but whilst i've got holes in the plasterboard i'm wondering what the best solution is. Do I stick a load of rockwool in there and hope for the best? Wary I don't want to get condensation and its got lights running along them so wary there could be a fire risk?

The gap is 180mm between the boards.

What tends to be the advice on this?

Cheers

 

[Swwils]

You'll need to get an effective cover of insulation for it to work properly, if you leave a large section missing lots of heat will escape.

Is it possible there is insulation in other areas and you just happened on a empty spot?

 

[0Floz0]

You'll need to get an effective cover of insulation for it to work properly, if you leave a large section missing lots of heat will escape.

Is it possible there is insulation in other areas and you just happened on a empty spot?

The roof is made up of a couple of additions (all done prior to my purchase). I think one section is insulated with rock wool. The other, larger part seems to have nothing. I can see into 4 of the gaps as we’ve got a big cut out where the steel went. So there’s a significant amount without insulation. Just need to make sure it’s not a warm roof. But pretty sure it isn’t as the kitchen is always cold. Will measure the depth of the roof to rule that out when the weather improves.

I’d have to insulate as a cold roof so don’t think I can escape not ripping all the plasterboard off as it’ll need membranes installing.

 

[oldbutnotdead]

Quick and dirty would be (if you have the headroom) ditch the downlights, overboard the ceiling with PIR and plasterboard, use LED flat panels for light.
More tedious- drop ceiling, put PIR between joists (not sure if you need a gap between PIR and underside of roof), again ditch the downlights.

 

[johnny2007]

You're selling, why are you worried about this?
Leave it as it is for the new owner to sort out if they ever will feel the need to.

 

[0Floz0]

Quick and dirty would be (if you have the headroom) ditch the downlights, overboard the ceiling with PIR and plasterboard, use LED flat panels for light.
More tedious- drop ceiling, put PIR between joists (not sure if you need a gap between PIR and underside of roof), again ditch the downlights.

Annoyingly I don't have the room so would be dropping the ceiling. However, if I changed the downlighters to be compatible with insulation (those hood things that go over them), could I not push rockwool through rather than using PIR? I guess with this I wouldn't have the vapour membrane so i'm wary it could cause issues? It'd mean I don't have to drop the whole ceiling and just keep it to the cut out bit. Just thinking of plastering costs!

 

[0Floz0]

You're selling, why are you worried about this?
Leave it as it is for the new owner to sort out if they ever will feel the need to.

It’s crossed my mind lol. But I’m not selling until march probably so would be nice for the house not to be losing loads of heat over the winter with energy prices as they are. So if there is a cheap solution to be done then it’d be nice to sort it.

 

[oldbutnotdead]

There's a can of worms opening up here. Have you had building control involvement for the (structural) steelwork- if so then I'd be surprised if they haven't spotted the lack of insulation.
And have you had any prices for plastering just the hacked out bit yet- be worth getting back to whoever priced and asking what it would cost to do the whole ceiling.
The downlights are going to be a pain. Stuffing rockwool in a hit and miss fashion isn't going to be ideal.
And remember you're going to have to declare this work on the vendor information sheet ('can't remember' isn't going to cut it for work done 6 months before a sale).

 

[0Floz0]

There's a can of worms opening up here. Have you had building control involvement for the (structural) steelwork- if so then I'd be surprised if they haven't spotted the lack of insulation.
And have you had any prices for plastering just the hacked out bit yet- be worth getting back to whoever priced and asking what it would cost to do the whole ceiling.
The downlights are going to be a pain. Stuffing rockwool in a hit and miss fashion isn't going to be ideal.
And remember you're going to have to declare this work on the vendor information sheet ('can't remember' isn't going to cut it for work done 6 months before a sale).

Not to worry. Building regs are involved and spotted the lack of insulation. The original ceiling was also signed off by an inspector so I think they're a bit red faced and not pushing me on it. They've ok'ed the steel.

Yeah downlights are my main concern with the rockwool. I might replace all of them and install the ones that have special covers on them so that there is no risk. My main concern is gathering moisture. I don't believe there are vents in the soffits to carry any breeze over the insulation, but I guess I can fit some?