View Full Version : Attaching joists to bearers
Loki429
3rd October 2007, 04:30 PM
What is the recommended method of attaching joists to bearers?
(I referring to joists sitting on top of the bearer, not supported by joist hangers.)
Is it acceptable to skew nail? If so how many nails per join?
Should I be using something such as the Pryda Triplegrips/Multigrips (whats the difference?) or Unitie? Is one sufficient per join?
Bearers for this deck are 250 x 50 and joists 100 x 50, both F14 hardwood.
The same question applies for the roof members.
cheers!
les88
3rd October 2007, 05:14 PM
skew nail from both sides
les
silentC
3rd October 2007, 05:23 PM
According to the NSW Timber Framing Manual:
Floor joists shall be nominally fixed to bearers or supporting walls at every crossing using a minimum of 2/75 x 3.10 mm skew nails. In addition, where there is only a single joist span in the full width of a house, every second joist shall be fixed at its ends using a framing anchor with 3/2.8 mm nails to each leg.
billbeee
3rd October 2007, 09:09 PM
Hi Loki429,
Do a test, skew nail a joist to a bearer, then rip it off with a 1200 long lump of 100 x 50 as a lever. Piece of p**s. Splits and bent everywhere.
Nail one on with a triple grip either side, with the correct nails, get a 4M long length of 150 x 50 as your lever. You will not come near to breaking it free.
If you only use one fastener per connection, stagger them alternate sides.
Most the fasteners have the same holding power, I like triple grips, but you have to buy L and R hand. The others you bend as required.
Sorry Les and Silent, I respect your opinions, but surely NSW can't be that backward. This day and age, skew nails? Did you read the last line about rafters also?
Cheers
Bill.
silentC
3rd October 2007, 11:52 PM
I'd imagine tie down requirements up in cyclone country would be somewhat more stringent than they are down here Bill...
Nobody in this neck of the woods uses triple grips on joists. Trusses, most definately. Skew nail first and then get the lackey (usually me) to run around and nail a triple grip on each one.
Yonnee
4th October 2007, 12:20 AM
I agree, and unless your decking is 8ft off the ground, there's not alot of wind loading to lift the deck/joists off the bearers, but your roof on the other hand...
Besides, there's usually alot more joists per square metre area, therefore more fixing pionts.
If you're worried about it, a box of joist straps are cheap. I have joist hangers at the house end, where the ledger/bearer is attached to the house at the same height, skew nails on the next two bearers (two each side), and the outside bearer has skew nails and joists straps.
Loki429
5th October 2007, 09:05 AM
Hi all, and thank you for your comments.
Just what I was looking for - some details from the standards and comments from experience.
If the joist straps are pretty cheap then I'll probabaly go with them. Skew nailing (by hand) on both sides through a hardwood joist into a hardwood bearer doesn't sound like fun!
For the roof trusses I'll stick with the triplegrips.
thanks