1930's loft, boarding it out

[britishboy7]

Our 1930's semi has a large loft area (floor area) but pretty low height, centre being 5'10" approx. We are gonig ot baord the whole loft floor out for storage, and insulate between the rafters (was going to use Celotex as used it before).

Between the rafters you can see the underside of the roof tiles, is this normal? (Was expecting a layer of felt or something i guess) Can I just cut the celotex and fit it between the rafters (leaving the air space between in and the tiles)

Also, going to replace the aging fibreglass loft insulation and replace with new stuff, any recommendations please? Or is it all pretty much the same?

 

[stealthwolf]

If you're insulating the rafters, do you really need to insulate the loft flooring?

 

[JohnD]

IF you want to fit new mineral wool roll, get the stuff treated with Ecose (it is brown, not yellow). It does not shed irritant dust and fibres. I would never use yellow fibreglass again.

It is actually made by Knauf but is sold as an own brand in the sheds. The wrapper will state "Ecose"

It feels fairly silky on the hands.

As you have an unfelted loft it will be filthy. Hoover it out (get a builders' canister vac) before and during work.

 

[britishboy7]

If you're insulating the rafters, do you really need to insulate the loft flooring?

Hi Stealthwolf, I just thought insulating the loft floor would keep the majority of heat in the main house, and prevent it rising up into the loft?

 

[stealthwolf]

Hi Stealthwolf, I just thought insulating the loft floor would keep the majority of heat in the main house, and prevent it rising up into the loft?

I've no real building knowledge and am just an amateur DIYer. What I've gathered is that you can have a warm loft or cold loft, depending on what you insulate but it appears to be either insulate rafters or insulate floorboards. Doing both to me seems overkill but worth reading into warm and cold lofts to see what you're after.

 

[geraldthehamster]

If you're insulating the floor and using it for storage, why also bother to insulate the rafters? A well-ventilated loft is a dry loft.

 

[Diver Fred]

Did that some years ago. Keep the 4'' of overceiling insulation or replace with new, stuff from the '70's (& 80's) has probably collapsed on itself.

With a house of that age you'll have 'proper' (cut) roof so when you cellotex between the rafters you'll have to make sure there is an air flow between the sides of the roof so you have to fit cellotex below the level of the ridge beam - leaving a minimum of a 2 inch gap.