Re: Are my joists strong enough?

by **Roy13** » Tue Aug 28, 2012 2:31 pm

I wish to board my loft with 18mm chipboard T&G. It will only be approx. 1 metre around the perimeter, mainly for additional storage space. Looking at previous postings this looks fine to do but what if I decided to board the total floor area? Would the weight of all the flooring AND the storage be too much for the joists?

If anyone can give me an answer on this one I would be truly grateful. The joists are approx. [b]80mm deep x 55mm wide[/b] and are spaced at 360mm intervals from centre to centre of joists.

I have looked at the TRADA website to find this information but nothing seems to relate to these sized joists.

Many Thanks.

by **andy01** » Tue Sep 11, 2012 8:59 pm

look at the superceeded building regs part A from 1992 i think on the planning portal website. span tables in the back. but i would say the timber are too small for any large loads.
from memory, the applied loads in in kilonewtons.
1kg/m2 = 9.8N/m2
1000kg/m2 = 9.8kN/m2

by **Perry525** » Wed Sep 19, 2012 4:54 pm

When it comes to ceiling joists, one has to take into account that from the sizes mentioned you obviously have a peaked roof. This means that the joists are under stress, pulled tight like a violin string, this means they are capable of holding reasonable loads. How wide are the unsupported spans?