loft insulation and storing stuff up there

[scorpiox1]

My parents have just had a guy from warm front round about putting loft insulation in, but he said they will put about 12'' depth of it and that they wont be able to put stuff up there again. is that depth standard and what's wrong of putting boxes and camping equipment back up there? they have standard depth joist and the insulation in there all ready is level with the joist but is about 10 years old and house is built 1904.

cheers

 

[Lower]

If you crush the insulation by putting stuff in the loft you lose most of its insulation properties.

 

[Space cat]

I seem to remember a time when four inches - being the typical depth of a ceiling joist - was considered sufficient. Then somewhere along the line it became six - and now it appears to be twelve. There's a diminishing law of returns on insulation in as much as each extra inch saves you less money than the last. I don't know who works these things out - or how - but I can see that rising energy costs will push the break-even point to greater thickness.

If you want to board your loft out for storage, I would think about adding extra joists at right angles to the existing ones, filling them up with insulation, then boarding over. You'll get the benefit of the extra insulation and still have a (somewhat reduced) storage space.

Edit: When we got our loft converted, the eaves spaces were left untouched; no extra insulation, nothing. So we did just what I described above then covered the inner roof and outer dwarf walls with T&G pine cladding. Result: Warmer rooms below and really useful storage space.