Fixing Plasterboard overhead with grab adhesive

[JoP1]

I'm converting a barn into living accomodation and wish to leave the inside of the sloping roof's timbers partly on show. After fixing Celotex between the rafters I'll then be covering the insulation with 12.5mm platerboard, possibly silver foil faced, purely for ascetic decoration (not fire resistance.
Rather than fixing timber battens to the rafter sides to screw the plasterboard to it would be much simpler and faster (no battens to fix, or screw heads to fill, as the boards won't be plastered) to apply a bead of 'Gripfill' (or similar) instant-grab adhesive in a line down the timber joists just under the insulation and then push the pre-cut plasterboard up between the rafters and squishing the adhesive with the cut edge so the it's forced down the cut plasterboard edge. I'd then support the plasterboard whilst the adhesive sets. Can you help with the following questions please?
1. Anyone tried this and with what result?
2. Do you think that the p/board strips (400mm centre rafters) would be too heavy to be supported with the p/board edges held by adhesive?
3. Your learned comments please - many thanks

 

[roy c]

Why dont you put panel beads over the edge of the plasterboard then pin the beads into the joists? I dont think you should "Stick" foil back with a grab adhesive as there is no "key" on the foil to let it "grab".

 

[JoP1]

Thanks for the bead under the p/board edges idea (perhaps quadrant?) - hadn't thought of that - but I'm really after a 'cleaner' look if possible.

I would agree with you about the foil's lack of grab, but what I'm trying to suggest in my question is that the bond would be principally between the rafter and the cut plasterboard edge - would it hold it?

 

[roy c]

No I dont think it would. And also it would be a bugger to get a nice finsh between plasterboard and rafters.You could box your rafters in (making them look a bit more "beefier") then they would hold your plasterboard in position and you would have nice clean lines.

 

[roughcaster]

There's lot of weight in a sheet of plasterboard, and to have it hanging overhead just held in place by a grab adhesive is a bit chancy.

 

[JoP1]

Roy - having looked at your answer again I now wonder if you mean something else, that I'm unaware of, by 'panel beads'.
I'd assumed you meant a supporting strip of timber, but perhaps it's a special bead I have (as a diy'er) no knowledge of. Were you referring to a special piece of plasterboard gear please? Many thanks for your help.

 

[roy c]

Roy - having looked at your answer again I now wonder if you mean something else, that I'm unaware of, by 'panel beads'.
I'd assumed you meant a supporting strip of timber, but perhaps it's a special bead I have (as a diy'er) no knowledge of. Were you referring to a special piece of plasterboard gear please? Many thanks for your help.

No not a special kind of bead .But what I meant by panel bead was the decorative beads that are used to make panels (beads that are mitred to make a panel on a plain piece of board or a door or a cabinet). There are a lot of different types of panel mouldings out there that you could choose from to compliment the rafter and the plasterboard. Quardrant is just one of these mouldings there are lots more. They come in hard wood or soft wood, you take your choice and you fix them to the rafter with....Panel pins of the correct length to suit the bead....

 

[JoP1]

Many thanks for all of your replies on this, to me, new and useful forum - it's been very helpful in making a decision.

I'll either be fitting 25mm wide x 50mm deep battens (50mm being the depth of the additional Celotex going betwen the rafters on this existing 'warm' roof) to the top of the inside of each rafter prior to fitting the insulation between the battens and then screwing the p/board to the underside of the battens, or I'll be using the beading suggestion.

You've helped totally in helping me to decide not to go the adhesive route, but if I hadn't asked....! I'd was hoping that someone had tried it sucessfully, but it's proved not to be - hey, ho.

 

[roy c]

My ole' man used to say ,"If you dont know, ask."

 

[JoP1]

My ole' man used to say ,"If you dont know, ask."wink:

With yer ole' man on that one.

I've now definatelty decided to follow your bead suggestion as on further thinking, in the bath, as you do, it will hide the cut edges of the p/board as well as support it. I'll stain the beads the same as the rafters before pinning them on and maybe paint the p/board white first too - it'll make a neat job.

Thank you again - Jo (Mr!)

 

[calorific]

An alternative would be to use a biscuit router bit to cut a groove and then use a thin ply strip instead of a decorative bead.

 

[JoP1]

An alternative would be to use a biscuit router bit to cut a groove and then use a thin ply strip instead of a decorative bead.

Nice suggestion also - many thanks