Internal Garage roof insolation

[redjay]

Hi,

I have an internal garage, one that forms part of my house. The problem is my little girls bedroom runs over the top of it and her room is freezing cold, when she opens her door the whole house goes cold due to the wind and cold air coming into our garage and then our nice warmair going out via her floor.

Any ideas on how to solve this problem!

[buildersmate]

Need to enhance the insulation in the floor. I assume you have plasterboard ceiling to the garage (you certainly should have or the house doesn't meet Building Regulations for fire separation). Then fill the gaps between the joists from below with rigid foam insulation (Celotex, Kingspan or similar) then nail 2 plasterboard layers back up again. Celotex is more expensive than fibreglass but easier to deal with and is about 4x the insulation properties for the same thickness.

[clever trev]

If the hieght of the garage allows ,the you could use some loft lagging with an added false ceiling of plaster board. the lagging you by is quite thick these days.

[clever trev]

Ok take no notice of me from past experiance buildersmate knows more about this type of work. but that is what i meant, but don't know of all the materials that are on the market. I must be younger than him ? :)

[redjay]

Thanks guys, builders mate you seem to know a lot about this problem. Do I lift the floor boards and fill that way or remove the plasterboard from the roof of the garage and do it ,then place a new one up there?.

I like the sound of the celotex stuff, what does that cost and do you need a load of fancy tools to do the job?

[buildersmate]

No special tools needed - it is rigid board that cuts like polystyrene with a simple saw. Has reflective layer on both sides.
I assumed that you wouldn't want to tackle the job by pulling up the boards from above.
Clearly it is uncomfortable working from below, but plasterboard is a cheap material to replace. Probably need a mini-skip to get rid of the old boards.
Remember that you must replace with the same - 2 layers with overlapping joints to maintain the fire barrier.

[beejay1124]

A handy tip that we do-when putting the stips of kingspan between the joists ,after putting them in place tap a couple of tacks in (into the joists& above what will be the level of the plasterboard)-this will keep them in place when you are putting up the plasterboard

[tezestwing]

just a point buildersmate the 2 layers of plaster board has to be plaster skimmed to achieve the usual one hour fire check regulation and if redjay was to staple this to the underside of the plaster boards through to the joists would that solve and still comply with the fire regs I know it wouldn't look to handsome but if it worked he could always over lay with plaster board at a later date. http://www.screwfix.com/prods/21112/Building/R oofing-Insulation/Airtec-Double-Insulation-1-0 5m-x-25m;jsessionid=HEN4CSPUCN4AACSTHZOCFEY?ts =91351 HTH Tez

[Lil O'lady]

Could it also be that a better-fitting garage door is the solution? I have a similar type garage with a bedroom on top, and the draught through the up-and-over door could cut in half in winter. I keep meaning to get it done properly but in the meantime I have covered it all up with bubble wrap and pushed bubble wrap into all the gaps! Not pretty, but very cheap, and it certainly makes the difference. I got the bubble wrap online from a company supplying packaging for removals. Needless to say said garage is not used for cars but for 'stuff', so the big door is never open in winter.

[buildersmate]

Thanks, Tez - didn't know that.
Lil - good fitting garage doors is really difficult to achieve. Better to kill the problem at source by improving the insulation.

[yydelilah]

Hi - I have exactly the same problem and will tackle it as advised.
Do I need to install a condensation membrane between the joists and the plasterboard ceiling?

thanks in advance.