Thin stud walling and building regs

Discussion in 'Builders' Talk' started by benwilso, Nov 5, 2006.

  1. benwilso

    benwilso New Member

    Dear all
    What is the thinnest I can make the stud wall to partition off a bedroom for an ensuite and comply with building regs?

    I've read on this forum about using CLS which looks like narrow studding, and also I've read that I need sound insulation. I will be tiling against the bathroom side of the wall.

    My guess is 3x2 studding, 12mm plasterboard on both sides, plaster the bedroom side of the wall and then aqua sheet the bathroom side of the wall. This gives me a wall about 4 and a half inches thick - is this the best I can do?

    Thanks all

  2. Willy Duwitt

    Willy Duwitt New Member

    Dont quote me on thi, but I dont think Buiding regs care how thick the wall is as long as it complies with their sound / insulation / stability standards, so if you could find some, say, 20mm board that fitted the bill there'd be nothing to stop you using that.

    From a practical point of view though, the 3x2 scenario you describe is probably the optimium size, given that standard doors are 1.5" or 1.75" thick.
  3. ProDave

    ProDave New Member

    You could save a fraction by using 9.5mm plasterboard.

    I think the CLS studwork timber is some odd measurement like 63mm or 69mm (can't recall which).

    I once built a stud wall using 2" X 2" where I wanted to save space and it worked well. I put the studs at only 300mm centres as they were thinner.

    I also recall the first house that I bought, I watched it being built. For the internal non load bearing walls they used a pre made wall system, that appeared to be two sheets of plasterboard joined together with a honeycomb cardboard filling, giving a total wall thickness of only about 50mm (a bit like the cardboard honeycomb filling used in some cheap lightweight doors)
  4. benwilso

    benwilso New Member

    Thanks fellas!

    Is this CLS sudding some sort of special wood that is structural so even though its narrow its rigid?

    Might look at using the 9.5 mm on the side of the wall that I will be putting the aqua sheet and then not plastering the 12mm side - that should save me 5mm (although I agree worrying about 5mm is starting to get rediculous).

  5. Controlled Magic

    Controlled Magic New Member

    CLS is Canadian Lumber Standard. It is selected timber that is then regularised. It is ex 4x2 or ex 3x2, hence the 89mm and 63mm dimensions. It isn't any more structural than any other stud, but the timber is nicer to handle. You make it rigid by adequate noggins and accurate cutting.

    B Regs don't affect a stud to form an en suite... you don't even have to have a wall between a shower and a bedroom, so why would they bother to specify a wall?!

    All the best
  6. jonah.

    jonah. New Member

    I always use cls for partitions now unless you have a good/ reliable timber supplier.

    In my own house I formed a cupboard filling in a large recess (had a reasonable wall area) using the 3 x 2 (about 63 x 38mm from memory) CLS and turned the studs 90 degrees (thinnest dimension) and at 300mm ish centres with 9.5mm plasterboard. The wall is solid as a rock

    CM is correct about the regs on walls between bedroom and its en-suite. It is sensible however to put some insulation in there if you can. Don't use ordinary quilt though - absolutely no point. The correct sound reduction quilt is of much higher density.

    Cheers - jonah
  7. trench

    trench New Member

    Controlled magic is right. The building regs specifically exclude sound insulation reqs for walls between ensuites and the bedrooms they are attached to.
  8. Stuart Fordham

    Stuart Fordham New Member

    Jonah did the wall bow over time?
  9. ajohn

    ajohn Member

    If you are worrying about the timber distorting it might not as the plasterboard and framing should help stop it while the moisture content settles down. The usual way of getting around that when furniture is made is to stack carefully with spacers between all surfaces so that air can circulate and on a flat surface at a temperature similar to what it will be eventually used in. Sometimes done in 2 stages. If it was straight generally is still will be. Even just the framing should have a very similar result.

    Probably best to get it from somewhere that sells lots. I bought some larger sized CLS for something else from Wickes. It split 2 days after it came into the house. They changed it for another piece that I selected. One of their minions told me it always was straight when it arrived. I have seen cls stud arrive at one place some time ago. Totally wrapped in polythene and sealed so the moisture content should be correct. Sounds like Wickes suppliers don't look after it, not the heavier stuff anyway.

    I decided to use metal furrings on a ceiling due to timber problems. The same can be done on walls. Getting it at the right price can be a problem, it took a lot of looking around and it ideally needs things like self drill screws for fixings that generally only come in rather large boxes. In my case it worked out cheaper than timber but I had to buy packs of the sections.


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