Fixing insulated plasterboard to timber beams

bdublin

Hi, I'm internally insulating my house. I'm going to fix batons to the wall (with damp proof course) and then add the insulated plasterboard. I have done a section, but having difficulty wit teh mushroom fixings. I got screws and the mushroom discs seperately. The problem is that when I screw them in the mushroom stands proud of the wall. Should it sink into the pasterboard, or do I need to skim over the mushroom (2/3mm)? Thanks in advance for any help. Best, B

sydthebeat

You use the mushroom fittings when fixing directly to the masonry wall.

if youre fitting to battens you simply screw the boards.

bdublin

Hi Sydthebeat,

I'm using mushroom discs and screws to go into the wooden rafters of the dormer as I was advised that just using screws could be risky. I had also planned on putting them on batons on the walls as it seems to be advised for moisure reasons. My problem is that the mushroom discs stand proud of 2/3mm, and i'm wondering if I am doing something wrong or are you just supposed to skim plaster over them. Also should I paint pva on them to prevent rust? Best, B

sydthebeat

i never heard of the mushroom fittings being used for fixing to timber work?? theyre not designed for that.

the mushroom fittings are used for fixing with them alone, or with adhesive dabs, directly onto masonry. you can hit them a good whack to recess them in this case.

if fixing to timberwork use clout nails, sherardised nails or dry lining screws.

but regardless, you need to apply a finishing gypsum plaster coat.

aujopimur

The black drylining screws and discs is the correct way, tighten well and they should end up flush.

Calahonda52

bdublin wrote: »

Hi Sydthebeat,

I'm using mushroom discs and screws to go into the wooden rafters of the dormer as I was advised that just using screws could be risky. I had also planned on putting them on batons on the walls as it seems to be advised for moisure reasons. My problem is that the mushroom discs stand proud of 2/3mm, and i'm wondering if I am doing something wrong or are you just supposed to skim plaster over them. Also should I paint pva on them to prevent rust? Best, B

You also need to make sure you meet any fire reg when using batons on walls.
You seem to be getting pretty bad advice or else there is a misunderstanding..
The proper drywall screws will not rush, ova will make it worse.

https://www.nsai.ie/S-R-54-2014-Code-of-Practice.aspx
will have some ideas