Flooring attic

Zulu

Hello,
I'm planning on flooring out my attic this weekend to create extra storage.
The insulation is upto 14 inches deep in places and I understand that it's not good to compress this.

My plan is to create an elevated floor support by running 2x4 beams between the struts (? the side of the triangle) parallel to the joists. And then putting half inch ply over those 2x4's. This way I dont compress the insulation at all and there's a nice airgap/air space between the insulation and the new floor.

My fear is that I should be placing the 2x4 perpendicular to the joists and spreading the load on the joists and not the roof. My fear is that by putting the load onto the joists I'm making a spectacularly naive and disastrous mistake.

Can someone please advise? Is my plan ok or moronic?
If its the latter, whats the best option? Run 2x4 perpendicular and dont worry about the compression that causes?

Thanks!

martinr5232

You can get things think they are called loft stilts or loft lifters that go onto the joist then sit your board on top of them.
I think woodies have them but im sure you would get them cheaper else where.

GreeBo

I did mine by going perpendicular, but I was adding more insulation between the "new" joists.

Zulu

martinr5232 wrote: »

You can get things think they are called loft stilts ...

Yeah I know, but they're 3 times the price and will take 10 times the amount of time to fit.

GreeBo wrote: »

I did mine by going perpendicular, but I was adding more insulation between the "new" joists.

Yeah, thankfully I dont need more insulation (new build; A rated and all that good stuff).

GreeBo

How much above the existing joists is the existing insulation?

Zulu

4 to 6 inches there there abouts.

Meningate

Depends what your going to use the loft for. If it's going to be for storage of heavy, or a lot of items, or if it's going to get a lot of foot traffic, 2"x 4" joists are not strong enough unless they are on top and fastened to your existing loft joists.
Also a half inch floor is unsafe, you need Three quarter inch floor grade ply minimum. Remember also that any vertical struts may not be struts holding up the roof, but hangers from the roof holding up the ceiling. This means they mark a weak point, not a strong point.

Zulu

Right, thanks, but this came a little too late!
I've got have the attic done Thurs/Fri. Seems solid enough, so i'm happy. I went with loft boards from B&Q for convience, and they seem to be spreading the load well.
I'm using the space for storage - usual rubbish (christmas decos etc) and I'm stacking the weight against the struts across the 2x4's so the weight is spread.

Delight with myself and my work. Fingers cross the roof doesnt come in over the coming days

GreeBo

Zulu

hahaha, it's all gone in over the spare room - just in case :eek: