I'm looking to add a 7"x3" timber to support the end of a bit of 18mm plywood which is only supported on 3 sides not 4. Access will be underneath from the garage below. I don't want to take up the floor above only bare minimum floor. So the joist hanger can't 'fold' over the attaching joists (as I would have to take up more floorboard) so can only fix to the face of the 2 joists. Can I use this 'Type 240 Multi Truss Hanger 47mm' (https://www.selcobw.com/type-240-multi-truss-hanger-47mm) to screw directly to the joist? It says I need 'M12 fixing' I assume this means a M12 hex screw (e.g. coach screw) so I need 4 x M12 fixings and a lot of 3mm twist nails per hanger? Is that right?
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Multi truss joist hanger
- Thread starter TryAgain1
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- joist hanger
The twisted nails are these: https://www.toolstation.com/sheradised-joist-hanger-nail/p96841. What about the M12 fixings? I can't find a M12 x 50mm to 75mm long structural screw. Any idea what these M12 fixings are?
So you're saying that it's structurally acceptable for me to use two 'Type 240 Multi Truss Hanger 47mm' (attached to joist with 'twisted 3.75mm x 30mm nails') on 7"x3" CLS timber with no M12 fixings? Structurally acceptable defined as no problems whatsoever and able to be signed off by building control?
This is getting confusing. There are always variables which affect fastener choice.
If you want to be sure, use a couple of these on each bracket, plus the nails.
www.toolstation.com
If you want to be sure, use a couple of these on each bracket, plus the nails.
Coach Bolt & Nut
These coach bolts and nuts have a place in almost every toolbox. They're zinc-plated and 75 mm long with an M12 thread. They are mainly used for joining timber to timber in low load-bearing applications, as well as timber joist construction.So whether you're assembling garden furniture, making a...
www.toolstation.com
This is a bolt - how can I use a bolt on CLS timber? Drill through the whole 3" of the timber then attach the nut from the other side?This is getting confusing. There are always variables which affect fastener choice.
If you want to be sure, use a couple of these on each bracket, plus the nails.
Coach Bolt & Nut
These coach bolts and nuts have a place in almost every toolbox. They're zinc-plated and 75 mm long with an M12 thread. They are mainly used for joining timber to timber in low load-bearing applications, as well as timber joist construction.So whether you're assembling garden furniture, making a...
You've got it. You'll need a 12mm timber drill bit or spade bit.
It might be a tight fit, but you can tap it through with a hammer on the domed end.
Tap it hard to seat the square section in the timber, this will stop the bolt from rotating when you tighten the nut against the washer.
I forgot to mention, you will need a 12mm washer to go with the bolt. A heavy duty round or square washer will do the trick.
You sound inexperienced, but you are trying.
Yes I am inexperienced. Most of my experience is with labouring/cementing/basic carpentry/push fit plumbing and end electrical connections. I have a full time job and do this part time.
The 7"x 3" timber is 47mm wide x 145mm high (abouts). So a M12 x 75 will go through the joist widthways and allow me to tighten the bolt on the other end.
Brilliant thanks. So, at the end: A 'Type 240 Multi Truss Hanger 47mm' attaching '47mm CLS timber' using both M12 x 75 (on all 4 holes) and twisted 3.75mm x 30mm nails (on all holes). Is this structurally acceptable so able to be signed of by building control?
Does it need BC? If it does, they'll give you a gold star. Better than a lot of the ****e they see!
You'll smash it, might even be an excuse to buy a fancy drill bit set. (I can recommend the Bosch expert self cutting spade bits, they make this sort of job a pleasure rather than a chore)
Thanks. I did screw up (lol) with other joist hangers and just used basic wood screws. BUT these were supplementary joist hangers because the 22mm chipboard spans over the noggins (held up by the joist hanger) and instead goes over the actual joist.
Yes. The big holes are if you want to fix to masonry with Rawl bolts, studs etc.
You sure that I can get away without using the M12 holes and just use the 5mm holes with sheradized nails (i.e. structurally sound and able to be signed off by building control?) Would be a lot easier if the case
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