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View Full Version : Using joist hangers instead of placing joists ontop of bearers?















Williamstown
18th September 2007, 04:49 PM
Further to my recent post about building a deck, I just read on another older thread about someone not laying the joists on the bearers but instead inserting them inbetween - attached with joist hangers. Placing them ontop will give me approx 120mm of ground clearance whereas using hangers between the bearers will give me approx 200mm of clearance.
Will the deck be just as strong using hangers or will it be stronger with them ontop?

oohsam
18th September 2007, 05:22 PM
Joist hangers are pretty strong and you would have no trouble doing it this way.
I prefer to pu the joists over the bearers if you can. If you have the space, which you do, go for it. It saves you on cutting the joists, nailing in the hangers. Im not sure how big your decking is but even if you had 5 rows of joists at 450mm thats still alot of cutting.
also - Wouldnt putting the joists ontop of the bearers give you MORE clearance not less ? I think you may have mixed up your measuerements.
Cheers.

mako
18th September 2007, 06:21 PM
The reason he would have more clearance is because if he mounted the joists level to bearer he would use differant size timber...say 140 x 45 in which case the total depth of bearer,joist and decking would be 165mm. if he put the joists on top he would probably be using 90 x 90mm bearers and 90 x 45 joists on top so total depth would be 90 + 90 + 20 (decking) =200mm. You need to worry about the clearance from the lowest part of timber to the ground which is the bearer if he put joists on top Hope this helps. Also in my experience using joist hangers is just as strong as joists on top.

Bleedin Thumb
18th September 2007, 06:42 PM
Guys, he's after greater clearance so if the joists are flush with the top of the bearer he can raise the deck to gain the extra clearance IE by the thickness of the joist.

Williamstown go for it, they would manufacture them if they didn't work.

mako
18th September 2007, 07:44 PM
Yeah, thats what i was tryin to say . that was easier !.:D

Williamstown
18th September 2007, 09:38 PM
Thats right. I have approx 320mm from the bottom of the door to the ground, so the top of the deck will be approx 300mm from the ground. I will have either 100mm clearance if I use 90x90 bearers adn 90x45 joists, or approx 150mm if I use 145x45 for the bearers and joists with joist hangers.

Could I use 90x90 bearers with 90x45 joists, using hangers to keep the top of the joists and bearers level, or should i be using 145x ?