I was thinking of installing Fermacell in the bathroom, but screws are a concern. It should probably be hard gypsum screws for those boards, right? Fermacell's own screws seem hard to get hold of and most others I have found are too short. I will install on 15 mm plywood and it should go about 20 mm into the studs, so 13+15+20 makes 48 mm.
Is 42 mm enough? The plywood is securely screwed into the studs, so it might not be absolutely necessary for the drywall screw to also go 20 mm into the stud?
Peter, my advice after searching like crazy for screws for fermacell is to drive to Hilti. They have screws with item number 2007807. They are perfect.
I believe they cost 278kr.
Check Hilti.se to see if they have the screws in stock first if you go with my advice
Well, but they're taped. I wasn't planning on renting a drywall lift for such a small area. Essve has 55 mm screws, but no one seems to sell them. Fredells had some packages left a week ago, so I might check there.
I find it strange that both Bauhaus and Byggmax sell Fermacell but don't have screws that are long enough if you're building a bathroom with 15 mm plywood behind the drywall.
Are you planning to have fermacell throughout the entire bathroom? If so, I think you can treat yourself to the luxury of renting a machine with a magazine.. it costs about 180kr per day and you'll likely be able to screw everything in a day with one of those.
By the way, I saw the skruv you linked but even they were trumpet. What you want is skruv that only has a cone and no "head" or whatever you want to call it.
How were the boards to work with? Does scoring and snapping work, or is sawing necessary?
Plunge saw and vacuum cleaner. Lowest speed, coarsest blade (expect a new blade afterwards) and don't cut all the way through, leave half a mm so it dusts the least.
I found good screws at Hornbach. Essve's had too much trumpet head to go into the board. Tried collated screws too, but my Makita battery screwdrivers couldn't drive the screws all the way in.
