Botch job insulating loft?

[Gavin1979]

Been up into the loft for the first time today in our new (1930s) house. Have found it to be a bit of a mess. The floor has been boarded using chipboard, not sure if there is much insulation under there, but the former owner has partially insulated the roof. The bottom layer of the roof appears to have been insulated between the rafters and boarded over, the rest is incomplete.

Has he done the job properly? There is no roofing felt, which is fine, but it worry's me how he has added thick insulation directly onto the slates

and boarded it.

We don't really need the loft space, so I would be inclined to rip out what has been done and lay a space blanket above the chipboard.

 

[Doggit]

Great intentions, backed up by a lack of experience.

It'd be worthwhile taking up the chipboard floor, and checking the size of the joists, as I suspect they've just boarded on to them. You can then use the rockwool used on the roof to insulate between the roof joists, and then add some more over the top f the joists. If you use a space blanket on top of the chipboard, then you'll be losing heat into the (more than likely) empty space under the chipboard. You should also be using 270mm of rockwool, and a space blanket wouldn't give that level of insulation.

 

[^woody^]

More like incomplete than "botched". It will be OK when finished. Not up to current standards, but that would be a while lot of different work if you wanted to go down that route.

 

[Gavin1979]

But is what he did okay? I've read on several sites, not to have anything touching the slates- which the rockwool is doing. I'm tempted to pull it all out and lay it across the chipboard which lies above the 2 main bedrooms so they are well insulated, then use the exposed parts for storage. There is already about 8cm of insulation between the ceiling and the chipboard between the joists.

 

[seasickstevie]

Has he done the job properly?.

Erm ... no.

As doggit said, great intentions, lack of experience.

You really need a membrane between the tiles and the insulation, separated by an air-gap of about 50mm. But if you don't intend to use the loft, it may as well come down, and be used on the ceiling.

 

[Gavin1979]

Finally got up there properly(new hatch). It was bizarre what he had done: insulation stuffed either side of the chimney; plasterboard screwed to the rafters, but only some had insulation behind it; piles of dirty torn up insulation left in a heap; propped up boards against the eaves.

There is 100mm of insulation between the joists that has been boarded over. The insulation between the rafters was only 100mm, so disposed of it all, now to clean it properly and lay 200mm insulation over the boards.