Foil backed plasterboard

[japher]

Just a quickie:

Where can I get foil backed plasterboard? I'm doing the ceiling below a flat roof, so I'd like the extra moisture protection and heat reflection.

I've tried B&Q and Travis Perkins, but neither seem to have any. Is there an online dealer that everyone is using? Failing that, is there a good alternative product?

Cheers

 

[noseall]

try using a 'builders merchant' as opposed to one of the sheds.

i,m surprised T.P. do not have any.

it is also known as duplex plasterboard.

 

[japher]

Thanks for the info noseall, TP do have the stuff on their website, labelled as 'duplex'.

Do you have any links to a good guide on fitting the ceiling? I need a little guidance on e.g. what screws to use, how often to place a screw, how to arrange the slabs of plasterboard, etc.

Also, I want to put some insulation in between the ceiling joists to give the room some added warmth. I've been given lots of conflicting advice from different DIYers Some suggest using the solid slabs and wedging these between the joists, some suggest basic rock wool. I've also just seen some sheeps-wool stuff in B&Q which is probably better for the ol' environment. Does anyone here have an opinion? Does it really matter which I choose, or will any of those options be fine?

 

[Deluks]

You can use any insulation you like, rigid kingspan/celotex type stuff gives best insulation for comparable thickness. If you have deep joists then by all means go with sheepswool if the eco credentials appeal.

The foil backed is to prevent moisture from getting out of the room, you can just as easily staple polythene sheet before putting normal plasterboard up. You can get vapour barrier roll for about £15 for 50 sqm

Mark where the centre of the joists are on the walls before putting the plasterboard up. Then you'll have a point of reference when screwing.
Use 12.5mm plasterboard with 50mm drywall screws, fix every 300mm. Experiment with torque settings on your drill until the clutch kicks in when the head of the screw is flush.

 

[japher]

Thanks Deluks, massively helpful!

For depth of insulation I have about 18cm to play with.

I'm still a little unsure about where the joints of the plasterboard should go and what sizes I should cut it down to. Assuming I use 1800x900 (easier to transport than 2400x1200), how should I arrange these? Should all the horizontal joints run along a joist? Does it matter?

From the top down, my bathroom looks like this (red lines represent the joists):

How would you guys cut/arrange the plasterboard to cover this room?

 

[Deluks]

Somebody already replied to this question, but the mods removed it. I'm not answering a question that's already been answered and then deleted because of mod interference.

 

[japher]

Hi Mod 7, is there any way to un-delete posts? is there any historical recording? If so, could you reinstate as necessary?

If not, can you even see who posted?

 

[japher]

I guess that's a no then

Deluks, sounds like this has irked you in the past, but can you find it in your heart to re-post/re-answer ?? Thanks in advance!!!

 

[DIYBaz]

DoBuild on ebay offer better prices than local builders merchant on foil backed board. Need to order 20 sheets though! Also sell Celotex at reasonable rates.

 

[japher]

Sorry guys, I'm bumping this post.

Can anyone answer the above question? (the one with the diagram)
(//www.diynot.com/forums/viewtopic.php?t=109947#738897)

 

[Deluks]

What's the distance between joists, and are they evenly spaced?

 

[japher]

The distance from the centre of one joist to the centre of the next varies from 40cm to 43cm.

 

[Deluks]

I'd use 3x 8x4 boards, one at the bottom left, long side against the left wall, another to the right of that with the offcut used to fill the 200mm odd gap at the top. Will need a mate to help, unless you have good manual dexterity.

Will be trickier to plan with 6x3 boards, I'd lay them with the joists, trimming off the excess 100mm on the centre of the joist as you go along. Supporting all joints is best practice, pick up a couple of lengths of 2x2 when you're shopping and use these as noggins where joints are.