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Green Building Bible, Fourth Edition
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    • CommentTimeOct 8th 2009
    Hey All,

    Anyone used Fermacell boards before?

    I spoke to the rep and he said after installing and fixing with joint stick glue you don;t need to skim it but instead cover it with Fermacell "fine surface treatment". I've heard others don;t even bother doing that and just paint it with no visible joints at all.

    What do we think? I'm finding it hard to believe the joints are invisible without skimming.

    • CommentAuthorJulian
    • CommentTimeOct 8th 2009

    it is easy to make invisible joints but your studwork and fixing of Fermacell needs to be spot on. It's 6 of one and half a dozen of the other 'cause the savings you make (time/material) if you don't skim it is pretty much cancelled out by the extra paint (no scientific evidence of this...) and work of painting the absorbent surface. The skimmed surface is much better for painting. You can get an immaculate surface if you skim or a good enough one if you don't.

    Are you screwing or nailing? If you're nailing a gun is best and means less filling. If screwing most cordless collated screwdrivers aren't up to it - mains is better.
    As julian said , very much like dry lining but superior , so 6 , 1/2 dozen
    The finish is slightly textured if you paint direct , joints are glued , sometimes requiring a slight fill
    which can then show up flat unless you can roll it out, adding a little texture as you lay off the paint.
    fixing with staples approx 15/40mm and a stapler (air or cordless) the way to go , much less to fill then
    Harder to cut than plasterboard and heavier , especially the 2.7/1.2 boards
    I like it , suits a timber frame build
    • CommentAuthorJulian
    • CommentTimeOct 8th 2009
    Absolutely James - and excellent for corners...strong and easy to shape. Interesting you use a stapler James...never thought of that. Have you tried a site saw (table) for cutting? Good for long thin strips eg just did a return to conceal T5 lights that way.
    • CommentAuthorPaul_B
    • CommentTimeOct 8th 2009
    I came across this video which is very good for demonstrating how to fix Fermacell, http://www.howcast.com/videos/115309-Fermacell-Drywall-Partition-Pt-2


    • CommentAuthorowlman
    • CommentTimeOct 9th 2009
    I've used it a couple of times, once for a large curved wall with an inset hole in the wall fireplace. I agree with James and Julian regarding fixings. Although I have a good selection of air nailers and staplers I didn't use them, maybe next time. instead I screwed the boards, come to think of it nailing probably wouldn't have worked on the curved wall. I used a mains power driver, no problem but a bit of a pain filling afterwards and the filled areas can, under certain light conditions show through the paint as smoother areas, if painting direct. So I ended up using the fermacell fine surface filler overall. The result was OK, if a bit tedious. The joint stick works fine, sets rock hard but is a bit of a bitch to sand, clogs the paper. Corner detail is good. I also used it on a small job and because I had a plasterer on site asked him to skim it along with some conventional plasterboard, Although he PVAd it first he remarked it wasn't good to skim using multifinish. Like I said it was a small area some of which I wanted to tile so not too much of a problem. As Julian remarked take care with the studwork, its unforgiving of sloppy work. I do like the rigidity, and solidity of it though. The walls "feel" and "sound" right, unlike plasterboard, but a bit more work involved.
    How's the boiler Julian?

    • CommentAuthorJohan
    • CommentTimeOct 9th 2009
    I use them quite regularly as well. Heavy to work with and you have can't score them with a knife you'll have to cut with a saw. that said they are far superior to plaster boards, as previously mentioned very good in timber frames.

    I always screw and get the plasterer to give them a skim if the wall is to be painted. It just gives that little extra with a smooth finish. They are a bit tricky to skim though as they suck the water out the plaster increadibly quickly compared to normal plasterboard. The plasterer I use now mix the PVA 2:1 instead of 5:1 to give himself a little bit more time to work!

    If wallpapering don't bother with the skim.
    ...so for a beginners guide what's so good about F'cell then...?

    • CommentTimeOct 9th 2009
    Thanks all for your comments.

    The only reason i would be using them is to eliminate the need for skimming. My studwork is all at 400mm centres and I don't need extra srength etc.

    I'm getting the feel that for these reasons alone the bigger price with Fermacell isn't worth it.

    Why do people say it's good for timber frame. Structural and rigidity purposes? I don't think you can't get it with foil backing so I assume it can't be for vapour control etc.

    And why aren't 4 tapered edge boards more comon in the UK like they are in Europe or US? Why are we still wet plastering everything I wonder??
    • CommentAuthorjamesingram
    • CommentTimeOct 9th 2009 edited
    some info here ,
    to me the benifit is it gives a good strong wall finish without plastering or skimming , so is the superior product for dry lining.
    I believe its enviromental impact is lower than standard PB.

    Wet plastering good for airtightness on a block construction
    • CommentTimeOct 9th 2009
    So James, you're saying that you've used it with a joint stick etc. the way the manufacturers advocate and the finished wall is good enough to be painted directly with no visible joints?

    Wet plastering is good in the above application but for any drylining fixed onto timber or metal studs surely 4 tapered edge boards are the way forward... Tape and joint a house in a couple of days... Less material...Still airtight cos all corners and joints are filled...

    Are we stuck in the past with regard to this one??
    • CommentAuthorjamesingram
    • CommentTimeOct 9th 2009 edited
    Well almost no visible joints. To much filler creates a smooth spot as mentioned , 3 coats should reduce this
    Went back to a place I did 2 year ago with firmacell and you wouldn't know the difference from a skimmed job except theres no joint cracking other than at the ceiling/wall junction were I used caulk
    the glues like that gorilla glue , but in a gun tube like caulk, its polyurethane (not nice)

    haven't looked at that how to link above , probably worth a look
    I agree with the tapered-edge but unskimmed PBs weak and prone to damage unlike fermacell ,
    Surpised they dont do TP fermacell , though you can do it yourself with a surf form (hard work ) or a electric planer
    • CommentAuthorPaul_B
    • CommentTimeOct 9th 2009
    Fermacell is great stuff. I think some of the comments maybe based on lack of experience and use plasterboard techniques on non-plasterboard material(not wishing to insult anyone). I believe the boards are less environmentally harmful than plasterboard. They can be scored, the joint stick approach makes a solid connection. You then are supposed to use joint filler (Fermacells) down the joint and over the screws. If texture is an issue the Ornage Book instruction details say to use joint filler and water to create a slurry and then just dab across the joint which gives a similar finish to the board. If you want to use a skim then use the Fine Surface Finished designed for the job. It is much easier to install for a DIY than plasterboard

    One huge benefit is the boards can be directly screwed and are rated at 25KG. If you use toggle fixings this increases to 50KG

    • CommentTimeOct 9th 2009
    Funnily enough I seem to remember that they do make a tapered edge board but then if the joints are invisible then why bother??

    The fixing issue is a plus but not crucial for me. I've got studs and nogs everywhere I need to fix something at present.

    What do we pay per sheet on this stuff?
    • CommentTimeOct 9th 2009
    Just got a price of £18.50 from local cheaper Builder's merchant. How does this compare with y'alls experience?
    • CommentAuthorPaul_B
    • CommentTimeOct 9th 2009
    My understanding is the tapered edged boards are specifically manufactured for the UK market to compete with plasterboard installation.
    • CommentAuthorJulian
    • CommentTimeOct 9th 2009
    Good post Paul. Julius are you in the SW? I think you may get a better price from Bradford's (hope that's not their price...). As Paul says there is a mid way between skim / no skim which he describes to lose the joints. I was told that Fermacell is made from 85% reclaimed gypsum (a byproduct from some other process) and the rest is cellulose (or old newspapers etc) like warmcel. So environmental impact seems a lot better than PB even if as Lafarge now claim PB now contains a lot of recycled gypsum. Fermacell is far superior for fixing to as said above and far more damp tolerant than PB. The result (as manufacturer points out) is akin to a blockwork inner leaf. With the best will in the world you would be hard pushed to say that of PB!
    Hi Mike I'll email you.
    • CommentTimeOct 9th 2009
    Yes, I'm in Hayle. Spoke to Bradfords before reading this and they came back with £15+vat per sheet so defo a little better. The trouble is you pay quite alot more with fermacell and so to fine surface it all over and have to buy different screws to the 15,000 collated ones I already have and filler it seems not so attractive.

    I'm going to spend a day next week with my proper builder mate and do some skimming to see how I get on. I've already got a collated screw gun and tools so it would be daft not to give it a whirl and see. I've done a fair bit of taping and rendering before so maybe it'll be feasible...

    Funnily enough via Encon or Minsters in truro I did manage to get a quote for a pallet of special order Synia board from Lafarge which is tapered on 4 edges but they screwed around with the order so much I told them to stick it. Maybe this was rash. Time will tell.

    Thanks all for your comments, J.
    • CommentAuthorTerry
    • CommentTimeOct 9th 2009
    We are in the process of drylining a substantial part of our renovation with fermacell.
    Cant remember the price, but think it was around £13 per 8x4 sheet of 12,5mm, but we bought a fair amount.
    Very heavy to handle and if you are not careful, they can snap when moving around. Not sure if relevant, but this seemed to only happen when things were a bit humid after a lot of rain when the boards were stored under cover but exposed to the outside air?? If I did it again I might opt for the 'one man' boards 1.0m x 1.5 me thinks. Obviously effects stud spacing though.
    Scoring hasnt worked well for us, but maybe due to our amateur status. We are using either a hand saw or a jig saw
    I was told by a rep a few years ago that the tapered edge was introduced for the UK market because the average UK plasterer or builder demanded it. I was under the impression that on the continent they dont use tapered edge.
    We are planning on painting directly on the boards. As mentioned above, the joints should be dabbed over with a slurry of the joint filler using a sponge. Will let you know how it goes when we get to that stage.
    Dont seem to recall seeing any mention in the instructions about nailing fermacell, only screwing and stapling. We have used screws and you do have to be careful with the studs as, if screwing too close to the edge and being a bit heavy handed with the cordless, you can crack the edge away. Would have thought a nail gun or hammer might give problems regarding this around the perimeter. No problems with cordless screwdrivers, even have to turn the torque down a bit.

    Benefits are that you have a much more solid wall that you can fix things to -seem to recall 35kg on a single 5mm screw as long as you have fixed the board as recommended. Studs can be at 600 centers and no noggins required.
    Removes the need for wet plastering :devil:
    They do absorb and release moisture in the air so can moderate conditions a bit - depending on what you paint it with of course.
    Easy to make curves. 4m radius when dry or if you need tighter, lay them over a former and cover with damp hessian and let it settle over night
    The sales bumf goes on about other pros, but cant remember them as the ones above are what we liked.

    • CommentAuthorPaul_B
    • CommentTimeOct 9th 2009 edited
    I'd have a quick look through the Handy Guide - http://www.xella-group.com/downloads/gbr/broschures/HandyGuide_s1104.pdf for example it discusses scoring and the use of an FST applicator rather than a normal plastering trowel for the FST. The approach is very different to PB.

    Other useful docs are listed at: http://www.xella-group.com/html/gbr/en/technical-downloads.php?area_code=3

    Or watch the video that I posted: http://www.howcast.com/videos/115309-Fermacell-Drywall-Partition-Pt-2
    • CommentAuthorRex
    • CommentTimeOct 9th 2009
    Very interesting thread as I am nearing the Fermacell stage of my build.

    My builder is using some PB in areas that are hard to reach and frankly, I cannot see the point of PB. there are so many fractures on the corners and edges (too enthusiastic with the cordless screwdriver?) that the amount of repair work seems to invalidate the money saved buy using it. So with the exception of the ceiling and some other high areas, it will be Fermacell all the way.

    This question is not intended as a hi-jack! Our house has some vaulted ceilings and hence high walls. In an effort to save a bit of cash, I am planning to use PB on the highest parts of the internal walls, where one would not hang a picture nor will be able to reach without a ladder.

    But I am slightly apprehensive about the 'joint' between PB and Fermacell. Anyone have knowledge of problems in this area?

    • CommentAuthorJulian
    • CommentTimeOct 9th 2009
    Hi Rex
    Have had PB/Fermacell and Sasmox interconnections - never had a problem. Plaster will seal the join effectively. Just make sure your studs/ceiling joists etc are well fixed and accurate.
    • CommentAuthorfinny
    • CommentTimeOct 19th 2009
    PB and an expensive wet plaster finish are the answer to a multitude of sins..
    Some of us get a kick out of doing a good job from studwork to finish, doesn't take any longer and the end result is better quality allround.
    Sounds a bit righteous I'm sure.
    I try to spec fermacell wherever I can and at home I always use it and use a 14.4 screwgun after predrilling. takes about 5 mins more per sheet..
    Rural mid wales price about 16 quid per sheet
    • CommentAuthorhitormiss
    • CommentTimeNov 22nd 2013 edited
    Weighing up using Fermacell with no skim in new build, against Plasterboard and skimming. Will be fitting boards myself with help. I would subcontract the plastering.

    I've done some drylining before and you can get a OK finish with a lot of effort, but it isn't as polished as a skimmed plaster finish IMO.

    Ceilings always show imperfections without a skim and Fermacell will surely look like a dry lined finish with joint lines etc.

    Quite like the idea of 9mm OSB under plasterboard to make fixing viable when decorated if Fermacell not worth pursuing.

    Any ideas, as Fermacell still seems a 'Bleeding edge' choice.

    I have a lot of walls and ceilings to do...
    • CommentAuthorowlman
    • CommentTimeNov 22nd 2013
    Fermacell needs finishing with their own ready mixed fine surface filler to get a good finish. The joints are glued and sanded off.
    • CommentTimeNov 22nd 2013
    Hayles is close to me, I always find Bradfords pretty good on price, bot that I have used them for a while now.
    • CommentAuthorbeelbeebub
    • CommentTimeNov 22nd 2013
    I would say that you can DIY a Fermacell wall and the end result looks as good as a skimmed PB wall.

    - Fermacell boards, ideally cut with a guided circular saw for a nice "square" finish.
    - the "Jointstick" to fully glue all edges, allow to "squish" out, wait 8hrs and it just pings off with a scraper. Try too early and it smears, to late and it's to hard (still doable but harder work).
    - Once the "Jointstick" has been scrapped away, fill any screw holes etc. with the filler (powdered mix). Wait about an hour for it to go off, then sand down with a lock and sand paper (or an orbital, but it's dusty!)
    - Finally, use the fine surface filler. it's premixed in tubs and has a texture like Philadelphia cheese. You can "cut" it with a little water to make it slightly thinner, then smear it on with a plaster's steel float. Smear each stroke on, then scrape it almost all off again. You should be able to see through the filler! Once that's dry (about an hour), the lightest touch of very fine wet and dry can remove any tool marks (again dusty!) and you are ready to paint.

    The above seems like a faff but it's just 4 stages. A 2 man DIY team could board out a wall in the morning, go for lunch, scrape the glue off in the afternoon, fill and fine filer it then get the first coat of paint on before the end of the day.

    Where Fermacell wins out is because you can DIY finish it, you can work in stages and not have to keep getting plasterers back.

    Right now, I'm finishing off my bathroom, I have some partition studs, about 2m2 with some alcoves and other fiddly bits. Getting a plasterer in would be a pain. WIth the FC I can work at my own pace and finish the walls when suits me.
    But you *can* very easily DIY finish tapered-edge plasterboard.
    • CommentAuthorhitormiss
    • CommentTimeNov 23rd 2013
    Thanks, I wonder why Fermacell is not more widely used?

    beelbeebub do you use one man boards or full 8x4 sheets? 12.5mm on ceilings or 10mm?

    400mm centres on walls & ceilings for full boards?

    Ceiling wise are you happy with the results with Fermacell fine surface filler.

    What is your preferred ceiling to wall detail?

    Thanks in advance.
    I've thought about using Fermacell, but what do you do where it meets a wet plastered masonry wall?

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