1930's house loft insulation -vpl or not

[ssray]

The eves of our loft are already insulated to about 300mm, the middle bit that is boarded and used for storage etc is boards screwed to the rafters ,so only 100mm if any at all.

I've been researching (sorry) my current plan is
Vcl
Insulation up to 300mm
Loft legs and reboard

The plan is lift the boards, clean the area (vacuum) check for nails, lay a vcl over and in-between the joists.
Using batts for the first layer then rolled rockwool type stuff.

The vapour control layer, understanding there are some expensive intillegent membranes out there, would I be ok using the same type of membrane that is under the tiles?
Ta Ray

 

[blup]

Do you need a vcl when the roof is ventilated?

Blup

 

[robinbanks]

would I be ok using the same type of membrane that is under the tiles?

The membrane that is under the tiles is likely breathable and not a VCL.

You don't need a VCL in a ventilated loft, don't need to check for nails or vacuum and rolled wool is typically obtainable in rolls that are pre perforated and can be torn into 400 or 600 wide before unrolling. If your rafter spacing are not a typical 400 or 600 then you can easily send a wood saw through the entire roll before you unroll it, to cut a custom width

 

[mcprinter]

Did my 1930s a couple of years ago.

Loft Legs work well.
They are only 175mm high so you should be using 170mm insulation with them. 270mm total.

 

[JohnD]

CONDENSATION IN LOFT (ANSWERS)

This seems to be the time of year for condensation in lofts, so instead of replying to lots of queries I though I would write this "one-size-fits-all" post. Please also see //www.diynot.com/wiki/Building%3ACondensation-in-Houses Condensation in lofts occurs when the amount of water...

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