Bending Battens to Curved Bay

Discussion in 'Roofing and Guttering' started by wingit, 30 Mar 2020.

  1. wingit

    wingit

    Joined:
    24 Aug 2007
    Messages:
    132
    Thanks Received:
    9
    Location:
    London
    Country:
    United Kingdom
    I'm renovating my bay window, circular segment kind of design. I need to bend some wood to form the tile battens.

    I already tried kerf bending some roofing battens, but with the knots and general quality of the battens, it wasn't working, they crack and split too easily, even when soaked.

    They need to be four metres long, so I was thinking that even if I steam them, by the time I've formed part of the curve they'll have cooled down enough to make curving the rest of the length too difficult.

    I'm now thinking I need to either get some good quality wood and kerf it, then paint on preservative, or laminate it. Can anyone recommend a good choice of wood for this purpose? I did play with the idea of laminating together 6mm marine ply in four layers, but I don't think it would be strong enough to hold the tiles in place securely.

    What would a roofer normally do? Just cut sections of roofing batten to form a rough curve?

    Thanks
     
    Last edited: 30 Mar 2020
  2. Sponsored Links
  3. palaceray

    palaceray

    Joined:
    3 Aug 2011
    Messages:
    248
    Thanks Received:
    58
    Location:
    London
    Country:
    United Kingdom
    You may find the easiest way is to buy 12mm lath as this will bend Around the curve easily. You can double it up to give a good thickness. If it is still too bouncy to nail the tiles, then you can screw them.
     
    • Thanks Thanks x 1
  4. wingit

    wingit

    Joined:
    24 Aug 2007
    Messages:
    132
    Thanks Received:
    9
    Location:
    London
    Country:
    United Kingdom
    Thanks, it doesn't look very easy to find four metre lengths. So, at the joins, because they will be under tension from the bend, I imagine there is more likelihood of a weaker fixing. Is there any technique to limit that?
     
  5. bobasd

    bobasd

    Joined:
    2 Dec 2017
    Messages:
    2,368
    Thanks Received:
    435
    Country:
    United Kingdom
    Good suggestion above but surely there's no need for anything but tile battens?
    I've never had difficulties bending around bays etc. and always used clout nails.
    Start on the middle stud, and work the battens sideways.
    Pilot hole and screw at the joins if you must, and angle the cut or pack out the stud with an off-cut of one by for bearing.
     
    • Thanks Thanks x 1
  6. wingit

    wingit

    Joined:
    24 Aug 2007
    Messages:
    132
    Thanks Received:
    9
    Location:
    London
    Country:
    United Kingdom
    Is that using 38x25mm battens?

    Maybe I bought poor quality battens, but even when I soaked them, they broke at the knots. The curve is quite a lot.

    The original battens from 90 years ago that I removed, were hardwood 1/2 by 2 inch
     
  7. wingit

    wingit

    Joined:
    24 Aug 2007
    Messages:
    132
    Thanks Received:
    9
    Location:
    London
    Country:
    United Kingdom
    could you explain that one a bit more please, I can't get my head around it
     
  8. bobasd

    bobasd

    Joined:
    2 Dec 2017
    Messages:
    2,368
    Thanks Received:
    435
    Country:
    United Kingdom
    yes, 38x25battens.
    in that case then do short lengths across a couple of bays or so.
    Or, Kerf the back of the battens.
     
    • Thanks Thanks x 2
  9. bobasd

    bobasd

    Joined:
    2 Dec 2017
    Messages:
    2,368
    Thanks Received:
    435
    Country:
    United Kingdom
    simply fix an of-cut to the side of the stud making say a 40mm stud into a 50mm stud.
    you could use a tile batten for this.
     
    • Thanks Thanks x 2
  10. Sponsored Links
  11. wingit

    wingit

    Joined:
    24 Aug 2007
    Messages:
    132
    Thanks Received:
    9
    Location:
    London
    Country:
    United Kingdom
    ah yes, thanks (y)
     
  12. catlad

    catlad

    Joined:
    29 Jul 2011
    Messages:
    4,995
    Thanks Received:
    761
    Location:
    Lancashire
    Country:
    United Kingdom
    Can you not bend them over several days with weights or clamps before you intend to use them.
     
  13. noseall

    noseall

    Joined:
    2 Feb 2006
    Messages:
    43,957
    Thanks Received:
    2,721
    Location:
    Staffordshire
    Country:
    United Kingdom
  14. datarebal

    datarebal

    Joined:
    1 May 2007
    Messages:
    3,442
    Thanks Received:
    709
    Location:
    Hampshire
    Country:
    United Kingdom
    decent quality batten, either cut in shorter sections or ply strips
     
    • Thanks Thanks x 1
    • Like Like x 1
  15. wingit

    wingit

    Joined:
    24 Aug 2007
    Messages:
    132
    Thanks Received:
    9
    Location:
    London
    Country:
    United Kingdom
    problem is, it's a 'cold roof' bay, and moisture would be present
     
  16. noseall

    noseall

    Joined:
    2 Feb 2006
    Messages:
    43,957
    Thanks Received:
    2,721
    Location:
    Staffordshire
    Country:
    United Kingdom
    Strips of 9mm ply could work just as well.
     
    • Thanks Thanks x 1
  17. wingit

    wingit

    Joined:
    24 Aug 2007
    Messages:
    132
    Thanks Received:
    9
    Location:
    London
    Country:
    United Kingdom
    I tried bending them, using hot water, over a few hours, but one snapped in two and another started splitting. So it would be a lengthy process. They would dry out overnight as well, and I noticed they creaked and sounded like they would crack as they dried out. I think it would just take too long to them all that way really.
     
Loading...

Share This Page