Insulating inaccessible loft space

[F]

We have a not-very-deep loft over a kitchen extension that needs some more insulation. The extension has a single pitch roof supported by a very deep purlin with hangers connecting the purlin to a batten which is connected to each ceiling joist. The batten has hangers fastened to it and the purlin above at the same centres as the joists.

All this means that access to that part of the loft nearest the eaves is almost impossible: I can hardly get my arm between the top of the purlin and the felt under the tiles, or between the ceiling and the underside of the purlin through the gaps between the hangers. Just to complicate things, the ceiling has downlighters installed that cannot be covered over.

There is currently around 100mm of glass fibre rolled out between each of the joists, and I can easily increase this in that part of the loft to which I have access through a hatch, but how do I increase the insulation in that section beyond the purlin and nearest the eaves?

[Harry Bloomfield]

My guess would be some form of blown into place, loose insulation. Something similar to a vacuum cleaner, but blowing the insulation out from the hose so as to reach the far, inaccessible corners.

[harryagain]

Blown in fibres? You could fit the fireproof boxes to the downlighters.

[F]

That was the only option I could think of but is blown whatever a d-i-y job?

No doubt someone will be along shortly to rearrange 'd-i-y', 'blown' and 'job' into a well know phrase or saying...

[chris French]

I don't imagine so. Given the equiment required. Are you in a position to get free insulation through the subsided scheme.

We had ours done under the subsidised scheme via the power companies, though that has finishes I think, and they blew in insulation to an fairly inaccessible part of ours.

DIY? hoe long is the inaccessible section. Could you maybe use some of that encapsulated glass fibre stuff and push it down with a long cane or something. The plastic/foil wrapper makes it pretty slippy.

this sort of thing:

[Jim Hawkins]

This is what I did in a simlar situation:- I covered the whole area with plywood boarding (you can slide that into the inaccessible areas), but leave a 2" or 3" gap under the eaves, and also along the opposite side. The heat from the downlighters can now diffuse across the space between the ceiling below and the boarding above, finally emerging in the gaps you left under the eaves and on the other side. . Now you have a loft with a floor which is ideal for storing all that junk in

- or for covering with that 100mm fibre insulation (except over the gaps of course).

Jim Hawkins

[spuorgelgoog]

It sort of is if you know someone who works for an insulation company and can 'borrow' the lorry for a couple of hours.

That'll probably be Adam.

Owain

[Timothy Murphy]

I have a similar problem, though I have a little more room in the roof-space. I was thinking of putting down Knauf or similar insulation board. I have enough room to push this to anywhere in the attic. I haven't seen Knauf insulation boards for some time, but I think Kingspan sell something similar.

If anyone has views on this I should be interested to hear them. I'd like something that adds a reasonable amount of insulation, and also supports moderately heavy storage cases.

[F]

That's the problem: the gaps into the eaves side of the purlin are each only 300mm wide and15mm high along the whole of its 7M length so sliding anything through won't happen.

The earlier suggestion of something that can be blown (poured?) in looks like the only possibility. It's a case of finding what to blow or pour...

[meow2222]

Totally, just takes a cylinder type hoover with a sealed up motor, ie the a irflow doesnt go thru it, some 32/40mm waste and some duct tape. Just watch how much you let it suck up, overdo it and it jams. Done this with polysty rene bead, not tried it with rockwool etc.

NT

[F]

I've got a Wickes/Earlex wet and dry vacuum so that part of the solution is sorted. Just need to find some 'blowable' rockwool.

Anyone?