RSJ cross beam size?

[glock339]

Hi I'm busy renovating (still!! ) my old house. I've boarded out some of the loft for storing the odd bit of stuff but have now realised that when I'm walking about up there the livingroom ceiling is bouncing a bit which is ok now as it's a mess anyway at the min but I will be sorting it soon. Now I did strengthen the existing 1" x 3" joists by adding a 4" x 2" on joist hangers next to each of them & screwing them into each other which I know is not great but thought I might do for a bit of light storage. (wrong )

I really cant face ripping up everything I've done so was wondering if I could put a cross beam under the lot as I'll be ripping down the ceiling underneath this part of the loft soon anyway? This would half the existing joists unsupported span from 3m to 1.5m. I'd then just box in the RSJ to match other exposed beams in the house.

If so what size RSJ would I need to be the cross beam spanning 4m?

Yes I know I should shell out for a S.E but really don't have the pennies rite now. Wort case scenario is I stop using the loft but I really could use the storage space.

Any help appreciated!

 

[RonnyRaygun]

How much ceiling will the RSJ be supporting?

 

[glock339]

The RSJ would be on a sat on a brick wall each end with just under 4 meters span between the walls.

It would be supporting the middle of about ten 4" x 2" wooden joists which are 3 meters long and spaced about every 400mm. 1.5 meters to the left of the RSJ would be the roof's king post and 1.5m to the right would the wall plate which is screwed into the wall.

The total size of this part of the ceiling is 3m x 4m = 12 square meters.

If you need any more inf just let me know

 

[^woody^]

Let's see .. £120 for an engineer

or a big pile of rubble and a sore head? Hmmmm

 

[glock339]

Let's see .. £120 for an engineer or a big pile of rubble and a sore head? Hmmmm

Yes I'm very aware that every single post involving anything like this ALWAYS has to have these comments. Big pile of rubble is a tad of the over dramatic thanks, I'm not a total f*@k wit ta and the only problem would be cracking some plaster on any finished ceiling that I put in when I'm walking about up there. I'm on about a few xmas decorations etc, not parking my car up there.

Anyway anyone else wants to add the usual comments feel free if you enjoy it, alternatively anyone wants to give me some useful advice regarding the a cross beam that can take my large weight bouncing about on it is very appreciated. I'd rather be go over engineered but at the same time I'd like to have something about rite rather than go crazy.

Thanks.

 

[RonnyRaygun]

Supporting attic loads only, 4 metre span, under the centre of joists spanning 3 metres, even allowing a bit more storage load than is usual, a 152x89 UB will be fine.

 

[^woody^]

Judging by the reply, it seems like this is a bit stressful, so get the builders who will know what they are doing, and you can relax a bit instead

 

[geraint]

Supporting attic loads only, 4 metre span, under the centre of joists spanning 3 metres, even allowing a bit more storage load than is usual, a 152x89 UB will be fine.

oh happy days

....

 

[glock339]

Cheers for the constructive reply RonnyRaygun

Judging by the reply, it seems like this is a bit stressful, so get the builders who will know what they are doing, and you can relax a bit instead

No need sorted it all out today with me old man who works for cups of tea and managed to get a 178 x 102 UB on the cheap off Gumtree, the floor/ceiling seems solid (will have to give it a proper bounce test once it has all set). Me is 1 happy bunny!