Fixing shelf to Steel joist?

[damson]

Hi there

I'd like to disguise a ceiling height plywood clad steel joist (put in by previous owners when two rooms were knocked through) by adding a shelf to it/making it into a shelf - so the shelf's back would be the vertical side of the plywood clad joist and the shelf's base would be cantilevered? off the bottom of the joist.

My question is what would be the best way to go about doing this and is it in fact possible/ok from a building regs perspective?

The shelf would hold cookery books and the odd ornament so a fair bit of weight.

Any thoughts/ideas/pointers much appreciated

thanks in advance

Damson

 

[damson]

Further to my original post I've done a little research and it seems there are several ways to fix wood to an RSJ.

I read elsewhere that the general rule is don't drill less than 1.5x the diameter of the hole away from the edge of the chord/flange (vertical bit of RSJ).

I found this post //www.diynot.com/forums/viewtopic.php?p=361935#361935 which suggested using bolts but what about using Tek screws? - Would they hold the weight of the shelf and the books on it. Shelf will probably bemade of 1 inch thick pine.

Opinions and advice much appreciated!

thanks

Damson

 

[Deluks]

Small bolts, 6mm will hold it. You could dowel the joint, so the the vertical bit against the beam, is sat over the shelfy bit. Thus negating any tipping of the shelf when load is applied.

How are you going to hide the fixing on the other side where it goes through the steel?

It's possible that the beam needs to be cased in for fire protection. So simply attaching a piece of plywood to the flange won't cut it. (sorry)

 

[damson]

Hi Deluks

thanks for that. In fact the RSJ is already clad in plasterboard, with plywood on top. I was going to fix the wood to sit underneath (as it were) the clad RSJ rather than sit it on the flange bits.

I guess I'd have to cut access holes to install the bolts which was why I was quite keen on the screw option. Would creating access holes for the bolts then mean recladding over the whole lot again to ensure protection from fire?

Because I need to fit the wood shelf underneath the RSJ (rather than sit it on the flange) mean I'd need bigger bolts - or just more of them? How far apart do you reckon they should be anyway? And the screws are a definite no, no, right?

thanks again!

Damson

 

[Deluks]

Ok got it, you should be fine with the screws then. That flange will likely be 10 -12mm thick, to a lot of to-ing and fro-ing with the tek screws, as these are really designed for thinner sheet metal. If the beam has been framed with 2x2 or similar then you could fix to that instead.

 

[damson]

thanks Deluks

Could I go for the poor man's version and use dry wall screws instead of the tek screws (apparently they will go through soft steel)? Should I aim to get scews long enough anyway to go through to the metal of the RSJ (and even out the other side of the flange) - and how far apart should I space them?

thanks again

Damson