Putting insulated foilbacked kingspan plasterboard on an existing ceiling

mayoman1973

As the current ceilings have a swirly plaster effect going on i want to get rid of this and also improve the thermal properties of the ceilings. To get 2 birds with the one stone im thinking of nailing 38mm kingspan boards to the existing ceiling. Would this work? Dont want to have to rip off the old plasterboard without a good reason for doing so. The old ceiling is prob up 25 years and shows no cracking or anything so its structurally good.

defforirl

You'll need to figure out exactly where the joists are behind the exisiting boards, use 60 to 70mm screws as opposed to nails and stagger the pattern of new boards.

650gs

Just knock a hole in the corner of the ceiling if it was done that long ago then just go 16 inch apart, a small hole should show you where your timber is do the same on the other side and run a chalk line across thats it a very easy job

mayoman1973

Cheers. So there should be no prob apart from the mechanics of putting the boards up? I'll have no prob finding the joists boring holes if i have to.

650gs

Get a hammer and knock a hole in tight to the wall and work back from that

Ush1

When you say ceiling is this the ground floor? If there is a liveable space above where you're putting the kingspan it might not be the best thing to do.

Is the existing plasterboard stuck to the underside of joists?

TheLastMohican

I'd be inclined to use screws instead of clout nails. If you are doing the same on the walls, you should do them first. This will stop cold bridging at the ceiling line.

mayoman1973

There is no living space above this, because I have the problem of old style swirly design on the ceiling that I want rid of I need to reboard the ceiling. Other wise just firing an extra 6 - 12" of rockwoll would give me the same thermal insulation gain without having the hasssle of reboarding the ceiling

jjf1974

I would leave the old ceiling in place as you would have the trouble of getting rid of the old plasterboard.Long plasterboard screws would be the best method of securing your ceiling. You can buy a special adaptor driver for a screwgun that wont drive the screws to far into the boards.