Timber size to bolt to steel beam

[djaychela]

I'm (slowly!) moving towards actually getting my extension built, and in the roof there's an RSJ that will be supporting the new dormer. The SE drawings show a 203x133 UB25 beam, with timber each side bolted to it, and below it will be the new roof joists (as in the diagram attached, circled in blue).

My question is on the timber to bolt into the webs. Standard size is 175x47, which will fit nicely in the web of the beam, but leaves around 13mm shy of the face, so the joist hanger wouldn't be a flat run down from that face.

Is this an issue? I can't see a correct size (175x63) in C24 anywhere.

The SE is pretty difficult to get answers from (I've been waiting 2 weeks for two simple answers from him, and the project has been delayed months because of this), hence asking here.

Thanks.

 

[Feck]

Rip down some plywood and fix to back of timber as a packer.

 

[Notch7]

As Feck says...just pack out the back.

The timber is only a convenient means of attaching joist hangers to.

The easiest way is to fix some 50mm x 13mm or similar lengths of batten vertically to the back of the timber - either side of each bolt position. Fix em on with screws

 

[djaychela]

Thanks chaps - much appreciated.