fixing joist to external wall

1 Aug 2005
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United Kingdom
Iam building a suspended wooden floor in an extension, the shortest span is from the existing external wall to the opposing wall. How do i fix the joists into this external wall, what choices do i have ? If i use joist hangers how do i ensure they are fixed securely.
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bolt a joist to the wall and fix the joist hangers onto this
I have a similar job to do - what type of bolt fixings would you recommend jbonding?
Assuming you don't want to put a bolt completely through the wall so that the nut would be inside the house; then you need to use Projecting Anchor Bolts.
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would this method be strong enough to hold kitchen units /appilances. have u got a link to these anchor bolts
Come on richjacq, do something to help yourself; the first hit from a google search shows you this;

You drill a hole in the wall and insert so that only the bolt on the right (where the nut is) is projecting out of the wall. Fix your joist on the bolt, followed by washer and nut. As you tighten the nut it pulls the conical shaped piece at the other end of the bolt towards it which causes those casing pieces along the length of the bolt (which are in the wall) to be forced open and expand thus fixing the bold firmly into the wall whilst securing the joist to the wall.
Don't know about bolt spacing, joist sizes etc, I would get those from a structural engineer.
Depending on the span, I prefer to see a sleeper wallplate for the joists to rest on, more solid and no bounce.
Depending on the span, I prefer to see a sleeper wallplate for the joists to rest on, more solid and no bounce
Would you then use those fixing bolts shown Masona or does it require anything more substantial, to go through the leaf of the wall and brace from inside the cavity maybe?

What I'm trying to say is how do you normally fix those sleeper beams to a cavity wall?

the joists iam using are 50x97mm
Wow they are small joists aren't they? 2" by 4"?
Can't be right surely?
With this level of questioning, do you really think this will be to regs and get approval !
when i discussed it with the building inspector i sugested placing the joists across the longer span (4.4m) with a sleeper wall in the middle as this would mean easy support of the hangers on the new wall. He said a sleeper wall wouldn't be needed at mid span if i placed the joists the shorter span (3.1m). it was only afterwards i wondered how was the easiest and strongest way of attaching them to the cavity wall. After another discussion with the inspector he said to hang a 75 x 170mm wide joist along the long span and hang the joists off that like jbonding sugested.
4 x 2 floor joists won't span 3.1m without a central support to cut it down to 1.55m, noway nohow

Have you thought about whatinsulation you will be putting in for the floor as your joists should be at least the same thickness to support properly

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