Query on loading capability of loft

[mofodave]

Hi all,

Stumbled upon this forum whilst googling for an answer to my problem but can't seem to see anything specific to my situation. I have just moved into a new build house and am looking to board out the loft. The ceiling joists are about 75mm deep by 30mm wide and the second floor ceiling (plasterboard) is screwed directly to the underside of these joists. I have a huge amount of insulation and was considering laying additional joists perpendicular to the existing ones so that I can make use of all the insulation that is up there and then board over the top so I can use it for storage.

Some additional info as follows:

• The beams I install perpendicular to the existing would need to be the same size at 75mm x 30mm.
• Existing beams are spaced at 600mm centres.
• I would be looking to install 600 x 600 x 30mm chipboard square boards on top of the second row of joists.

My question is, will the existing 75mm deep beams take this or will I be overloading them and asking for trouble?

 

[big-all]

lofts are for light storage only
if you have say 2 close walls underneath[1-1.5m] you could make a platform over that area and around 500-600 beyond dependant on sheet material size with anything heavy over the walls
this assumes the walls give support to the timbers on top