What screws for wet plasterboard equivalents?

There is nothing to stop you using stainless pozi screws. You just have to be careful how far you screw them in as they wont cam out like drywall screws.

You can also use stainless nails.

I think those will do the job -

Stainless, 3.5mm so quite fine, good sharp tip, drill/cutting thread should clear the PB without cracking and the heads have flutes which should allow them to countersink again without undue stress.

I think it's a case of suck it and see - but I used a heavier version of this make of screw (5mm/30mm) to install guttering into cedar boards and I was very impressed.

/I think those will do the job -

Stainless, 3.5mm so quite fine, good sharp tip, drill/cutting thread should clear the PB without cracking and the heads have flutes which should allow them to countersink again without undue stress.

I think it's a case of suck it and see - but I used a heavier version of this make of screw (5mm/30mm) to install guttering into cedar boards and I was very impressed. /q

Yup suck n see, tho watch how hard you drive them they are brittle especially the thinner ones IME

Jim K

I've used these bits before - they ensure it cams out at the right point:

I don't think you want self countersinking ones. Maybe

I think you probably do - the idea is not to stress the board near the edges by forcing stuff in so a drilling/cutting action is probably better.

But without doing a head to head test, I cannot prove you wrong :)

Drilling and countersinking are different.

If you cut through the paper you lose a lot of the strength. But very near the edge may be an exception as the edges can bulge out. But plasterboard i s usually a lightweight plaster that can take a bit of compression. I took down some really old plasterboard in my house and it was basically just pla ster of paris - very rigid with sharp edges where it cracked ! Simon.

I was careful to say the link I provided, the screws do both.

/sm_jamieson

- show quoted text - If you cut through the paper you lose a lot of the strength. But very near the edge may be an exception as the edges can bulge out. But plasterboard i s usually a lightweight plaster that can take a bit of compression. I took down some really old plasterboard in my house and it was basically just pla ster of paris - very rigid with sharp edges where it cracked ! Simon. /q

But we're not on about plasterboard....:-)

Jim K

But you don't want the countersinking as it removes the surface and you don't want to do that.

/But you don't want the countersinking as it removes the surface and you don't want to do that. /q

Er the surface of what??

Jim K

Remember, this isn't plasterboard - it's cement board. To look at it, it doesn't look like it has a surface layer, although the cutting instructions (score and snap) claim it does, but it's probably not paper. I haven't yet tried to make a hole in it yet.

ear the edge may be an exception as the edges can bulge out. But plasterboa rd is usually a lightweight plaster that can take a bit of compression. I t ook down some really old plasterboard in my house and it was basically just plaster of paris - very rigid with sharp edges where it cracked !

The stuff I've used (Knauf IIRC) has, on both sides, just below the surface , a ?fibreglass? mesh (similar to plastering scrim but thicker and in board

-sized sheets).

I don't recall it having a "surface layer" per se, think it's just "cement" with 2 X fibreglass layers - a sandwich.

making holes is OK though it's very abrasive and shags normal hole saws and drill bits pretty quickly, & anything "powered" makes lots of 'kin 'orribl e fine dust....

Jim K

If they suggest that you can use plasterboard screws then they don't cut the surface but compress it. I would use a stainless screw that does the same.

Never had this problem with Asbestolux!

Never had this problem with Asbestolux!

Ah the 'good' old days:-) & all done with his shirt & tie on...

Jim K

He'd have to, otherwise his new found middle class status would be in tatters.

ear the edge may be an exception as the edges can bulge out. But plasterboa rd is usually a lightweight plaster that can take a bit of compression. I t ook down some really old plasterboard in my house and it was basically just plaster of paris - very rigid with sharp edges where it cracked !

Ah well, there are various types of waterproof wallboard for bathrooms. Som e are a sandwich construction. I used something like "viroc", was a cement board with some type of "mineralised" cellulose filler. I used aquapanel sc rews on it which have little projections on the back of the screw heads for self countersinking. But I think I just countersunk the holes anyway when I fitted it. Simon.