Fixing insulated plasterboard - general advice

[endecotp]

Yes you just hammer them in. Screw head is only for unscrewing if necessary.

Re depth into wall - if it were 40mm into brick I'd be reasonably happy, but I suspect your wall is 25mm of old plaster and then 15mm of brick, or actually mortar if you hit the wrong spot...

Personally I'd be happy with that head shape to fix plasterboard, after all plasterboard screws have a countersunk ("bugle") head. Some care is required not to over-tighten (over-hammer!) and damage the surface of the board. If you go for a head that's flatter then the screw head will sit above the surface of the board. Are you planning on skimming? How much head thickness will that hide?

You can get special fixings with a huge flat washer head, possibly plastic. (Do a google image search for "mechanical fixings for insulated plasterboard"). I think they're mainly used for (a) holding just insulation boards without PB, (b) when there's no adhesive and you're using many fixings and the heat conduction through the fixing is a concern. I think they need to be skimmed over. I suspect that the plastic ones will not survive a fire, and remember that's the only purpose of these fixings.

 

[JP_]

Well, Toolstation had none I wanted, Screwfix did not have those Fischer ones (they were remarkably unhelpful), so got these from B&Q. More expensive per screw, but I don't need many.



My plan is to fix them along the line where I'll put a new picture rail, so it should not matter too much if it looks a bit messy, or if they stick out a little as I can always shave a little off the back of the rail where the screws are, if needed.

Screwfix, unbelievable.

 

[JP_]

First bit of plasterboard is in the wall! Either wall or floor not straight, so there's a gap. Do I just cut bits it board to fill in?

 

[Doggit]

Use bonding. I'd stagger the boards, and fit the next one towards the top - or at least put it up there and check the levels first.

 

[JP_]

Ah, too late!

I'll keep it simple. Next time, if there's a next time, I'll stagger a bit!

 

[JP_]

Suppose it's a good time to check if I have a 10mm SDS drill bit....
Should I use wood bit for the board and insulation? Or SDS all the way?

 

[Doggit]

SDS all the way will be fine, but you could just go non hammer to start with if your worried.

 

[JP_]

Skirting boards. .. as mentioned, the one under the bay fell off when I was cleaning up, revealing that it too had rotted in parts - mostly the end on the left, where I had the joist rot. I assume the rot cam from below.
However, just to be safe, and also because I have a bathroom cabinet on the wall that is expanding due to build up of moisture ... I thought maybe the skirting problem could also be due to condensation.

So, I'm thinking of getting plastic skirting boards and fixing them with foam. This should improve insulation, reduce risk of condensation dripping down to floorboards, and eliminate risk of rotting skirting.

Does this sound like a good idea? Is there a flaw in the plan?

Looking at these, have requested a sample. https://www.eurocell.co.uk/interior...150mm-ogee-skirting-board-in-white-satin-x-5m

 

[JP_]

Room staying warm and dry. Window on latch for ventilation too, thermostat on 19, so operation seems to have been successful. Mostly cosmetic finishes to do.

 

[John D v2.0]

I'm guessing it's too late but you can foil tape all the joints in the insulation after foaming as a belly and braces on the vcl/airbarrier. We did that on the floor insulation and it worked a treat, although don't but screw fix version of the tape.

 

[JP_]

Yeah, just foiled a bit more actually. If there's a join, it gets foiled.