Hanging Joists off RSJ

[richo106]

Hi All

 

My internal steels are going in next week and then it’s down to me to do the joists (posi) they are all on site ready to go. 

 

I have a beam that will have joists fitted to it both sides (see attached pic - beam highlighted red)

 

I was planning to clamp 2 pieces of timber in the web using 12mm tapped rod so the joist hangers can be screwed to these. The UB has 14mm web holes at 600 centres. I was going to sink the washer/nut so it doesn’t affect the joist hangers etc. 

 

Please see attached drawing I have done to show my plan, does this look ok or is there a better method of doing this?

 

Does the timber need to be perfect fit or would you leave a slight margin for error? Or would it be better to be perfect fit especially the depth? 

 

The joist hangers are MHE 380-75-152

 

Daft question…will any wood screws be ok to fit the hangers? Certain size required?

 

Any advice/information greatly appreciated 

 

Many Thanks 

[nod]

The easiest way is to bolt a timber in the beam prior to lifting the steels in Then simply nail the hangers in 

It took me about two hours to do eight steels Very easy on the ground More tricky when in situ 

[nod]

Just now, nod said:

The easiest way is to bolt a timber in the beam prior to lifting the steels in Then simply nail the hangers in 

It took me about two hours to do eight steels Very easy on the ground More tricky when in situ 

 

[Mr Punter]

Depending on the joist sizes you can often just shape the ends to fit in the steel with noggins between.

[richo106]

Thank you

 

@nod I was hoping to do them on the ground but the steel guy is bringing them to site and dropping them straight in unfortunately 

 

Does your timber fit perfectly flush to the front of the RSJ? Will a mm either way hurt? 

[nod]

4 minutes ago, richo106 said:

Thank you

 

@nod I was hoping to do them on the ground but the steel guy is bringing them to site and dropping them straight in unfortunately 

 

Does your timber fit perfectly flush to the front of the RSJ? Will a mm either way hurt? 

The two pictured did with the corners planned The deeper ones needed a rip of 10 mil ply 

I cut all mine ready and put a couple of bolts in each and lifted in place with the steel guy Then spent a couple of hours drilling the Timbers and bolting 

The steel guy will expect this 

[nod]

Just now, nod said:

The two pictured did with the corners planned The deeper ones needed a rip of 10 mil ply 

I cut all mine ready and put a couple of bolts in each and lifted in place with the steel guy Then spent a couple of hours drilling the Timbers and bolting 

The steel guy will expect this 

[ToughButterCup]

When I had questions about our POSIs, I rang up the manufacturer, and talked it through with their designer. To double check (because I knew less than nothing about the matter) I rang Cullens. They put me on to one of their design team and we had the issue sorted out straight away.

 

It shouldn't surprise you to say that their advice was to exactly what  @nod   suggests.  We chose German wood-to-steel screws. Worked like a charm. On the few screws that appeared not to 'cut' into the steel , we simply spat on the screw tip ; spit , it appears is a cutting agent (who knew that eh?)

[ToughButterCup]

@nod, your sites always look so bleedin' neat ...... no rubbish, no M/T beer cans, no piles of [....] 

[Miek]

Fix the wood at ground level if you can, so much easier. 

 

Usually timber hangers are fixed with sheradised twist nails, not screws.

If the wood is a bit proud of the steel it won't matter IMO. 

[richo106]

1 minute ago, Miek said:

Fix the wood at ground level if you can, so much easier. 

 

Usually timber hangers are fixed with sheradised twist nails, not screws.

If the wood is a bit proud of the steel it won't matter IMO. 

Looks good!

 

Thanks for the comment regarding the twist nails rather than screws (I did not know this)

 

This was my thinking regarding the wood, would rather be a little proud (mm or 2) 

[Mr Punter]

57 minutes ago, Mr Punter said:

Depending on the joist sizes you can often just shape the ends to fit in the steel with noggins between.

 

I have just re-read the OP and note these are Pozi joists, so shaping the ends ist verboten.

[richo106]

16 minutes ago, Miek said:

Fix the wood at ground level if you can, so much easier. 

 

Usually timber hangers are fixed with sheradised twist nails, not screws.

If the wood is a bit proud of the steel it won't matter IMO. 

https://www.screwfix.com/p/easyfix-square-twist-nails-sheradised-3-75-x-30mm-1kg-pack/12788?kpid=12788&ds_kid=92700048793290424&ds_rl=1249413&gclid=EAIaIQobChMIxOnNw7Oc_AIV4I9oCR0f5A6bEAQYAiABEgLJXPD_BwE&gclsrc=aw.ds

 

Something like these?

[nod]

41 minutes ago, ToughButterCup said:

@nod, your sites always look so bleedin' neat ...... no rubbish, no M/T beer cans, no piles of [....] 

Thanks Ian 

We try 😁

[Miek]

27 minutes ago, richo106 said:

https://www.screwfix.com/p/easyfix-square-twist-nails-sheradised-3-75-x-30mm-1kg-pack/12788?kpid=12788&ds_kid=92700048793290424&ds_rl=1249413&gclid=EAIaIQobChMIxOnNw7Oc_AIV4I9oCR0f5A6bEAQYAiABEgLJXPD_BwE&gclsrc=aw.ds

 

Something like these?

Yes that's them. 

[Miek]

42 minutes ago, richo106 said:

 

 

Thanks for the comment regarding the twist nails rather than screws (I did not know this

Nails are stronger in shear than screws. If in doubt fill all the nail holes in the hangers is my advice. 

[richo106]

20 minutes ago, Miek said:

Nails are stronger in shear than screws. If in doubt fill all the nail holes in the hangers is my advice. 

Will do👍

[ToughButterCup]

1 hour ago, Miek said:

... 

Usually timber hangers are fixed with sheradised twist nails, not screws.

...

 

I found that placing the nails before hammering them in easier if the nail is jammed into the tines of an (old) table fork before placing the nail in the hole in the hanger. Hammering the fork - and not my fingers - was less painful.

 

Cheaper too: fewer plasters needed.

[Canski]

2 hours ago, nod said:

Thanks Ian 

We try 😁

I agree, this is the way I like to work.... A tidy site is a happy site. But ... if you don't do it yourself it won't get done.

[saveasteading]

5 hours ago, nod said:

 

 

 

4 hours ago, ToughButterCup said:

We chose German wood-to-steel screws.

Or good swiss or good french. I would only buy branded screws from a specialist supplier. Make sure they are "heavy" spec for going into a beam rather than a purlin. Tell them the timber width and web thickness.

 

(TBC btw what german manufacturer are you suggesting?)

 

Nearly all good screws go in first time. With cheap ones the first is often only effectively a drill bit and discarded, so you need twice as many. The advantage of screws is speed and you can fix more if you feel inclined, and less precision required.

 

[nod]

1 hour ago, Canski said:

I agree, this is the way I like to work.... A tidy site is a happy site. But ... if you don't do it yourself it won't get done.

So true 

 

Last summer I did the plastering and tiling on a self build not far from Ian 

She purchased a beautiful caravan with a store office and a toilet After eight weeks only the brave would use the toilet let alone use the office or tool store 

[richo106]

Morning All

 

I have just noticed on my drawing (and in bags i have now received) they have specified/sent 152mm high joist hangers for my 225mm posi joists

 

Is this normal? I don't want the building inspector to pick this up once I have done it

 

Many Thanks 

[PeterW]

Unusual as they normally have to be the full height of the joist to provide rotational support. Who has designed the floor ..??

[richo106]

7 minutes ago, PeterW said:

Unusual as they normally have to be the full height of the joist to provide rotational support. Who has designed the floor ..??

Company called Pasquills, supplier of the posi joists

[PeterW]

Ok I would go back and confirm with them as they are normally pretty good and this may just be an oversight.