Complying with building regs - garage ceiling insulation?

attila_

Hi I've finally come round to buying some insulation for my garage roof.

Reading building regs I see for garage ceilings I need to put fire retardant plasterboard which makes most of the insulated plaster boards useless (such as this: http://www.wickes.co.uk/Knauf-XPS-Laminate-Plus-Tapered-Edge-2400x1200x27mm/p/163699)

I was wondering whether this could work:

http://www.wickes.co.uk/Wickes-25mm-General-Purpose-Polystyrene-1200x2400mm/p/210823

Followed by this:
http://www.wickes.co.uk/Knauf-Fire-Panel-Tapered-Edge-2400x1200x12-5mm/p/190539

I was going to glue them together and then screw them to the ceiling.

What are folks' thoughts on this? Thanks v much!

Hasbeen

attila_ wrote: »

Hi I've finally come round to buying some insulation for my garage roof.

Reading building regs I see for garage ceilings I need to put fire retardant plasterboard which makes most of the insulated plaster boards useless (such as this: http://www.wickes.co.uk/Knauf-XPS-Laminate-Plus-Tapered-Edge-2400x1200x27mm/p/163699)

I was wondering whether this could work:

http://www.wickes.co.uk/Wickes-25mm-General-Purpose-Polystyrene-1200x2400mm/p/210823

Followed by this:
http://www.wickes.co.uk/Knauf-Fire-Panel-Tapered-Edge-2400x1200x12-5mm/p/190539

I was going to glue them together and then screw them to the ceiling.

What are folks' thoughts on this? Thanks v much!

Not an expert, One will be along later?

I would have thought normal insulation to required thickness placed between upper floor and two layers of fire retardant plasterboard staggered if I remember to cover joints? would be sufficient.

Ensure any electrical cables can breath.

Perhaps best advice would be from council planning/building control office?

YouKwoteMe

Hi,

I would say no for the simple reason that toxic fume would still be released as soon as higher temperatures are reached in situations of fire. Unless these are also heat resistant which I doubt. The same with the "glue" you mentioned it would have to be fire and heat resistant for the same reasons.

Hope this helps

Regards

attila_

Ah ok thanks I'm a bit stuck then. I can only access the ceiling on the garage (its an integrated garage and bedroom upstairs).

Is there an insulated plasterboard which is fire retardant?

Doozergirl

I presume younare trying to insulate the room above rather than convert the garage?

If so, You don't need to meet regs if the regs didn't exist and therefore weren't met initially. Your only obligation is to make sure that nothing is worse than it was originally.

To meet current regs, as suggested above, a double boarding of ordinary plasterboard is sufficient for fire protection so you can choose any other insulation to suit.

Insulated plasterboard definately has a place as it can save on labour when you're paying for it.

attila_

It's an integral garage with a bedroom above which is getting very cold. I am trying to avoid lifting the floorboards so insulating from the garage ceiling.

The house is built 1994.

MX5huggy

If you know there is no or very little insulation between the ceiling joists. You need to take the existing garage ceiling down (maybe you are planning to). Then I would fill totally the space between the joists with standard loft insulation if you cut it slightly wider than the gap it will hold it's self until you get the ceiling up, do a bit at a time so you don't come back next day to find it all on the floor.

You need to fill between the joists else drafts would render insulation put under the joists useless.

Then to improve performance further (just the loft insulation probably does not meet the level required in a new build today, which is not a requirement but a good guide to a level that is reasonable to achieve) I would under board with 50mm of Celotex (or other PIR/PUR insulation) large headed nails will hold this until you get the plasterboard up.

Then plasterboard either with 2 layers of standard or 1 of fire proof, the fire proof will be heavy consider smaller boards ,hiring a plasterboard lift or a plasterboarding party for your more burly friends. Screw the boards up don't nail.

Doozergirl

attila_ wrote: »

It's an integral garage with a bedroom above which is getting very cold. I am trying to avoid lifting the floorboards so insulating from the garage ceiling.

The house is built 1994.

As I said. No requirement to meet regs at all, but regs are best practice.