Loft floor boarding

330d

Looking to put down tongue and groove floorboards in my loft to create some storage.

The floor joists are only 100mm high, meaning when I screw the floor boards direct to try joists, I will only have 100mm insulation.

Will this be an issue?

grumbler

IIRC, the current requirement is 27cm of mineral wool. Even if you use Celotex (or similar) instead, it'll be about 15 cm.

Personally, I'd just use 10cm Celotex as much as possible, but this will cost about £15/m2.

Gavin83

Use loft legs. It’ll allow you to lift up the boards and get the required amount of insulation underneath.

FreeBear

Gavin83 said: Use loft legs. It’ll allow you to lift up the boards and get the required amount of insulation underneath.

Two sizes available - Standard length at 175mm, or XL at 300mm.

With 100mm joists, go for the standard 175mm ones and use T&G chipboard - This will give you enough space to put another layer of fibreglass insulation down and hit current recommended levels.

330d

Thanks for the replies.

I have seen the loft legs but wasn't sure how widely used they are. I've spoken to a few people who boarded there loft but did not use them.

Murmansk

The shorter loft legs are good and I prefer tongued and grooved boards made of OSB rather than chipboard. I got mine from Wickes.

Lastonestanding

Murmansk said:

The shorter loft legs are good and I prefer tongued and grooved boards made of OSB rather than chipboard. I got mine from Wickes.

I put plywood in my loft, thought it might be stronger and lighter 

330d

Murmansk said:

The shorter loft legs are good and I prefer tongued and grooved boards made of OSB rather than chipboard. I got mine from Wickes.

Lastonestanding said:

Murmansk said:

The shorter loft legs are good and I prefer tongued and grooved boards made of OSB rather than chipboard. I got mine from Wickes.

I put plywood in my loft, thought it might be stronger and lighter 

Thanks. Did either of you use the loft legs?

gazapc

As an alternative to 'loft legs', in a previous house I ran lengths of timber perpendicular to the joists and mounted boards to that. Can't remember the exact timber size but it was something around 150 x 40mm. That way you could get a good amount of insulation underneath. With recent timber price increases, not sure how it stacks up against loft legs but it was cheaper at the time.

Liverpool85

We had the company that do loft legs around to quote but they said the product wouldn’t work well with our loft we too many trusses (newish build pyramid hipped all 4 sides) 

instead our loft guys used timber to build a frame that meant 30cm of insulation was fine, then border on top of this, has worked well 

Lastonestanding

330d said:

Thanks. Did either of you use the loft legs?

I didn't, it would have been a more complex job, I just use it for storage.