I would like to add to ceiling binders to my loft, to stop any chance of flexing. Can these binders be supported from the rafters and pirlins, I intend to use 2" x 2" timber for both binder and hangers, is it best to screw these to the hangers or use bolts. The binders are less than half way across the span from the suporting wall. I also intend to add 2" x 2" timber to the top of the joists between these binders. I have seen it done before professionally, but they failed to say how they connected the joists to the hangers. Would I need a hanger from every rafter or less. The span from the supporting wall is 5' and the binders are 14'6" in length. The rafters are 4" x 2" and on 16" centres as are the 4" x 2" ceiling joists, the pirlins which are 9" x 3" are fixed 18" above the current joists. Any help please.
PS. I have a drawing of the roof but, can't find out how to paste it here.
Use 3 x 1 timbers and fix to the ceiling joists at 90 degrees to the run of the joists at 2 m spacings. Then fix a brace diagonally on to the roof rafters on either side of the roof. You could also use noggins between the ceiling joists or better still metal herring bone straping.
Also screwing should be fine. Hope this helps. :D
I have done this now and what I did was this.
1. screwed 2"x2" timber below pirlin and glued and screwed to each joist.
2. glued and screwed 2"x2" on top of 2"x2" timber, to fabricate 4"x2".
3. bolted a piece of 2"x2" timber to bottom piece of 2"x2" and to the rafter, every third rafter.
4. screwed a piece of 2"x2" timber to all other rafters and to both other pieces of 2"x2"
5. glued and screwed 2"x2" timber to joists and bottom piece of 2"x2" timber between each vertical, therefore in effect making an "L" shape.
The floor doesn't seem to flex at all, it is 15mm chipboard screwed to 2"x1" timber laid at 90o to the joists at 10" centres.
Dont worry about future fixing using glue.(Never done on site)
Timber being a material that expands and contracts(related to moisture content), you might find that the glue joints might crack or split. Dont worry about this, as the metal fixings will hold firm.Might be worth insulating below your floor coverings. Also it is normal practice to use Tongue amd groove 22mm chipboard flooring (8x2)sheets as floor covering.Glueing the T & G joints with PVA glue :D