Loft Joists

The message from Joe contains these words:

My 1965 reference says 6" x 2" floor joists @ 16" centres have an allowable clear span of just 10' 3". Modern figures may be marginally different.

For light use (and a computer set-up probably counts as light use) I think you could get away with a bit wider span particularly if the loading isn't in the centre. However Building Control might not like it.

I could be wrong, but I thought that there were much more stringent regulations that apply if the room is classed as a "habitable area". A PC acting as a server or something would be fine, but a computer desk (=office??) sounds like its becoming a proper room. Then you'd have to consider fire/access/ventilation etc etc. In other words, a proper loft conversion, with building control involved. Jon.

Who's going to know? If he does nothing that can't be undone if/when he wants to sell then it's a non issue apart from worrying about his own safety in the event of fire.

MBQ

Thats exactly it. I'm not wanting to go through planning and all that

- just want to get the loft insulated and sealed up. Thats why i was asking about the joist loads. Can anyone answer that one ?

Ta.

Joe.

Cheers Roger,

I'm presuming the 10'3" clear span is the length of one end of joist on support wall to another. Is that right ?

Joe.

Taking the pragmatic approach again, if the loft joists are the same size as the floor joists in the rest of the house for the same span then, obviously, they are adequate by the "standards" that ruled when the house was built. I doubt very much they would meet modern standards for a floor but it may just mean you get a bit of extra bounce and may cause cracks in the ceiling below. They're not going to collapse, otherwise what holds up the other floors in the houose?

I wish my modern loft joists were 6x2! They're more like 3x1.

MBQ

The message from Joe contains these words:

Yes.

Then your 6x2s have plenty of strength. Its the old 3.5x1.5 joists over similar distances that are borderline. 6x2 over 10' would not give any ceiling cracking problems unless you went nuts up there, waterbeds etc.

NT