Green Building Forum - Fermacell 8 x 4's Anyone used them?? Fri, 12 Jun 2026 22:48:52 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Fermacell 8 x 4's Anyone used them?? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=189931#Comment_189931 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=189931#Comment_189931 Sat, 23 Nov 2013 17:44:25 +0000 Jonti Posted By: hitormissThanks, I wonder why Fermacell is not more widely used?



I think that Plasterboard is quite a bit cheaper.

Jonti]]> Fermacell 8 x 4's Anyone used them?? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=189936#Comment_189936 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=189936#Comment_189936 Sat, 23 Nov 2013 20:11:01 +0000 hitormiss Fermacell 8 x 4's Anyone used them?? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=189939#Comment_189939 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=189939#Comment_189939 Sat, 23 Nov 2013 22:01:16 +0000 Nick Parsons Fermacell 8 x 4's Anyone used them?? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=189975#Comment_189975 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=189975#Comment_189975 Sun, 24 Nov 2013 12:09:45 +0000 hitormiss I've thought about using Fermacell, but what do you do where it meets a wet plastered masonry wall?

I'm going to use 25mm x 50mm treated batten on the Hi7 Block walls, (100 Dritherm 32 full fill cavity), with Tyvek Airguard Reflective against blocks inside (for airtightness). May use some thin 15mm or 25mm Celotex before Airguard. I don't want to lose to much internal space. Not sure if it is worth worrying about the Celotex.

Outside is Tyvek Housewrap over Hi7 blocks, then treated 25mm x 50mm battens, then English Cedar (North Devon) F/E cladding 200mm wide fixed with stainless nails.

Fitting battens to blocks with Twistfix hammer drive fittings. http://www.twistfix.co.uk/thermalite-fixings-airtwist?cat=32103 I have also used Tapcon screws.]]> Fermacell 8 x 4's Anyone used them?? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=190092#Comment_190092 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=190092#Comment_190092 Mon, 25 Nov 2013 16:46:59 +0000 MikeRumney
Much better racking strength
No need to fix on stud line as it'll take 50kg without plugs if done right
Better sound proofing

Against:
Care needed with long thin sections (say 2700 by 250 mm) as it has a tendency to snap under its own weight.
More of an issue if its the slightest bit damp.

I wouldn't use it on a ceiling myself as even the "one man" boards are on the heavy side.
I've used plasterboard screws with a cordless drill driver into 12.5mm with no issues except the occasional friction-screeching noise!

Do a countersink in the board first to bury the screw heads a bit.
Makes the skim / fill easier.
(Drilling a pilot hole right through not so useful as you'll get breakaway on the back,
which will either stand the board off the stud if left, or dramatically thin the attachment point if picked away.)

I haven't yet used any jointstick as all the edges share the same stud, making them dead level and not likely to move relative to eachother.

Powdered polyfilla and 20/80 PVA/water makes an excellent "flexible" bonding/filler/skim by the way.]]> Fermacell 8 x 4's Anyone used them?? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=190119#Comment_190119 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=190119#Comment_190119 Mon, 25 Nov 2013 19:19:15 +0000 davidfreeborough Posted By: hitormiss
Posted By: davidfreeborough I've thought about using Fermacell, but what do you do where it meets a wet plastered masonry wall?.
I'm going to use 25mm x 50mm treated batten on the Hi7 Block walls, (100 Dritherm 32 full fill cavity), with Tyvek Airguard Reflective against blocks inside (for airtightness).I mean how do you avoid cracking where the two meet? Do you plan to leave a gap between the Fermacell & the plaster? If so, what will you fill the gap with?

As an alternative, is it possible to use paper jointing tape, plaster over it with the finish coat & cover the part on the Fermacell with the Fine Surface Treatment? Would you need a tapered edge board?

David]]> Fermacell 8 x 4's Anyone used them?? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=190121#Comment_190121 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=190121#Comment_190121 Mon, 25 Nov 2013 19:35:20 +0000 jamesingram You can plane fermacell to make a tapered edge]]> Fermacell 8 x 4's Anyone used them?? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=190200#Comment_190200 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=190200#Comment_190200 Tue, 26 Nov 2013 14:58:17 +0000 djh Posted By: davidfreeboroughIf so, what will you fill the gap with?
Shadow!? That's what my architect is suggesting anyway.]]> Fermacell 8 x 4's Anyone used them?? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=190203#Comment_190203 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4655&Focus=190203#Comment_190203 Tue, 26 Nov 2013 15:06:24 +0000 jamesingram all the go for the swish!]]>