Joist hanger question

[Rollin]

Can joist hangers be used to fix two joists at different levels like this?

[JR]

Yes. Depending on the dimensions you may need to modify the higher joist.

[Hedders]

Physically , yes. Not sure if it is up to code though. Where is that going?

[Rollin]

The higher joist is about 4m long but can be any cross section as needed. It will be supported at each end by supporting brick walls already present. The lower will be one of a number of floor joists that will span about 100cm so can be smaller.

It's going to be the floor for a bathroom as discussed on another thread. Trying to get things straight in my head before the structural engineer comes round.

[Spudler]

Rollin said:

It's going to be the floor for a bathroom as discussed on another thread. Trying to get things straight in my head before the structural engineer comes round.

He may be happy just to see the higher joist doubled-up and bolted together or, as its a bathroom, want something more substancial.

[JR]

Rollin said:

The higher joist is about 4m long but can be any cross section as needed.

In that case just increase the depth of the upper joist so that it's underside is level with the underside of the incoming joists.

[Rollin]

JR said:

Rollin said:

The higher joist is about 4m long but can be any cross section as needed.

In that case just increase the depth of the upper joist so that it's underside is level with the underside of the incoming joists.

The higher joist will sit across some ceiling joists where as the lower joists will run between ceiling joists.

The lower joists are going to join with another floor area which would then be at a lower level and can't be raised.

[herbialfa]

I would sat double up the larger of the joist bolted together at 500mm centres with M12 bolts.

Then you can hang the smaller joists off it no problem!

If the smaller joists are running the same way as the existing (which the must do sureky????) lay the new joists along side and screw the old to the new!

[Rollin]

herbialfa said:

I would sat double up the larger of the joist bolted together at 500mm centres with M12 bolts.

Then you can hang the smaller joists off it no problem!

If the smaller joists are running the same way as the existing (which the must do sureky????) lay the new joists along side and screw the old to the new!

The joists in the existing bit don't run the same way unfortunately.

[JR]

Given that the lower joists only span 1m you can make them fairly stiff and you can notch them under the larger joist - i.e. extend them under the larger joist, don't notch the larger joist. As long as the diff in levels of the underside isn't too great you'll be OK.

Be sure to make the larger beam stiff enough that it doen't deflect onto the ceiling joists below.

Edited by JR on Friday 5th November 20:25

[mk1fan]

It's a shame you haven't got a Structural Engineer to look at the layout and give you some options.

[Rollin]

mk1fan said:

It's a shame you haven't got a Structural Engineer to look at the layout and give you some options.

I have, but I wanted to get a little bit more understanding of what may or may not be needed before they come round.

[stimps]

Just suspend the joist using a couple of these hangers:
http://www.screwfix.com/prods/84068/Building/Build...

[redeye]

stimps those hangers are for brick or block walls not timber to timber .
hanging a joist lower than its cross member support is common ,you may need to stop the lower joist from moving under the main support joist ie; nogging below main joist to the depth of the hanging joist.
notching the hanging joist and using side hangers is a good way (see simpson joist hanger site)

[Solitude]

Use mastic !!!
(Save a fortune on those overated joist hangers)