Loft floor and wall insulation advice required

[tjg]

I'm looking for a bit of advice about insulating a loft.

I have a small loft space above my (integrated) garage next to a bedroom. It is the area defined in red in the diagram below.

The plasterboard walls at the back of the built-in cupboards are currently not insulated. What type of insualtion would be bets for this? My initial thoughts are to use some sort of solid (polystyrene?) insualtion.

I would also like to improve the insulation in the floor (i.e. the garage ceiling). At present there is some sort of fibre, wool-like insulation. It is patchy, and bothers me as I suspect I am losing heat from the bedroom to the garage and then outside.

The space is currently unused, but my intention is to put chipboard down on the floor and use it for storage (ladder free access, unlike the main loft).

Any thoughts and help would be greatly appreciated.

 

[jbonding]

kingspan in the cupboard walls and rockwool would help, is the garage ceiling double boarded with fire line boards? as much insulation ie rockwool in the garage ceiling would help,maybe another skin of rockwool in the loft aswell, the more the better.

 

[tjg]

Thanks for the reply.

I don't think the garage ceiling has got fire line boards. It's certainly only a single layer of boards. Do you know if there is any building regulation for this?

Regarding your advice about Kingspan in the cupboard walls, I've had a quick read around on Kingspan. They offer many products. Are you suggesting using some of their dry-lining boards?

 

[jbonding]

there are fire regs, all the garage ceilings ive ever boarded on new build has had to have two skins of fire line boards staggered and skimmed, with rockwool between the joists , this is for obvious reasons ie whats stored in there. i mentioned kingspan as an isulation not the boards but theres another choice.

 

[tjg]

Nice one. Cheers for the reply. I shall find a supplier in my area and get working on it.

 

[tjg]

What I have read indicates that the insulation should be continuous or at least butt together over the garage ceiling, dwarf wall, pitched roof and into the main loft.

Can anyone tell me what material should I use a vapour barrier/control between the insulation and the plasterboard on the warm side?

Thanks.

 

[Loony Paul]

What I have read indicates that the insulation should be continuous or at least butt together over the garage ceiling, dwarf wall, pitched roof and into the main loft.

Can anyone tell me what material should I use a vapour barrier/control between the insulation and the plasterboard on the warm side?

Thanks.

I have a similar situation to yours, my house is a 3 story 100 year old semi with no insulation between the sloping walls and the roof tiles, which have no sarking felt.

I plan to work from inside hte house, talking the exisitng lathe and plaster slope off, insulating between the rafters with kingspan or similar the ones that look like a crunchie with foil on. Also celotex do similar stuff. Then use laminated insulated plasterboard over the lot.

Because my roof has no sarking felt and ventilation is not a problem on the cold side I dont plan on using a vpm but most people will advise you to use on unless your loft space is very well ventilated. I thought any old plastic sheet would do...

HTH.

 

[tjg]

Thanks for the reply Loony Paul. I've not done the insulating yet because I'm a bit concerned about the ventilation. I need to fit a couple of airbricks up in the main loft to ensure there is air flowing through as well.

This whole vapour control layer thing is really confusing me. I can't see why "any old" plastic sheet wouldn't be ok. I guess I will have to just go for it in some way shape or form and then keep a close eye on things for a while - learn by experience...

 

[JohnD]

the vapour barrier has to be on the "warm" side of the insulation, otherwise condensation will form on it. Have you considerd foil-backed plasterboard?

 

[tjg]

Thanks for the reply JohnD. I'm now going to go down that route (using the foil-backed plasterboard). It's a little more expensive, but surely well worth it for keeping the house properly insulated.