Loft flooring help

[Jacka]

Hi all

After having a little time out, i’m just about finished the bathroom….. and in the new year i’m moving on to the next little job…

I hope this makes sense….. but I plan to board out the small loft over my extension for storage and I need to raise the height of the joists to allow for the insulation and don’t fancy using the stilts. I have 4x2 ceiling joists with rock wool in between, then more rockwool lying across the top of them

I have a span of approx 2.4 m. If I braced another 4x2 from wall to wall with hangers, would you sit them directly on top of the existing joists doubling them to 8x2 or would you sit them above but in between the, with noggins resting on the existing??

Any help and advice would be great.

Thanks

Jacka

 

[slawit]

Personally, I would sit them on top like you say using joist hangers, and for what it’s worth then screw them together to make effectively a 8*2. Are you adding more timber to add strength or just gain height for storage? Only reason I ask is there might be an alternative method to rockwool if your 4*2 is going to be strong enough to support the weight of storage and boarding out. Could you use polystyrene sheets across the 4*2s for added insulation? If they are dense enough, they will easily support the weight of your boards and storage and the occasionally the weight of you going up there. Just a thought.

 

[robinbanks]

and don’t fancy using the stilts

Why not?

 

[Jacka]

Personally, I would sit them on top like you say using joist hangers, and for what it’s worth then screw them together to make effectively a 8*2. Are you adding more timber to add strength or just gain height for storage? Only reason I ask is there might be an alternative method to rockwool if your 4*2 is going to be strong enough to support the weight of storage and boarding out. Could you use polystyrene sheets across the 4*2s for added insulation? If they are dense enough, they will easily support the weight of your boards and storage and the occasionally the weight of you going up there. Just a thought.

The insulation is already there and to save cost I just want to reuse, but it sits about 100-150mm above the existing joists, so I’m just looking at raising it. I made the mistake of boarding my main loft on top of existing joists and removing insulation….. i think we lose a lot of heat, something i’ll rectify when i gain this space.

I know in the past you could buy loft boards with poly insulation beneath them, but don’t seem to do them anymore.

 

[Jacka]

Why not?

I think for the cost, i’ll get the timber cheaper and I think it will be sturdier.

 

[Murdochcat]

If it’s a small loft don’t bother raising the floor level. I suspect any saving will be tiny