Specification for loft flooring

[stevendt]

I would like to floor the loft for storage, nothing heavy, just general clutter. B&Q have loft boarding in 18mm chipboard at 1200mmx350mm, this would be fine for getting through the hatch (which is pretty small) but is not suitable for my needs. It is recommended for maximum joist centres of 450mm and mine are 600mm.

Can someone suggest a suitable board for this purpose ?

regards
Dave

 

[JohnD]

I used that size board for the edges of my loft (before I discovered I could just manage to manhandle an 8x4 slab up there) but counterbattened the rafters with additional timbers at right-angles. I used 75 x 38mm which my timber merchant had on offer.

You place the counterbattens at intervals which allow you to place the edges of the boards on one timber, then add one or two more in the middle.

It spreads the load and gives more rigidity when all screwed together. It also increases the "floor depth" so you can add greater thickness of insulation.

It's OK for light loads but doesn't actually make the loft floor strong enough for anything heavy. For that you would have to add deep new joists supported off the walls.