This page will cover the ceilings in the extension.


The first job was to get the fibreglass insulation into place.

This picture demonstrates my working method. First I fixed two battens to the underside of the joists, the insulation was then laid onto these and lifted up into the gap between the joists. With the battens taking the weight in the centre the friction against the joists held it long enough to pull the netting under the lot and staple it into place. When the section was complete the screws were removed from the battens and they were drawn out.


Moving my platform as I went and working around the room all the insulation was installed.

The two lessons learned during this were:

1. Cut the insulation to the right size, if it was too long and I tried to squash it in it would sort of fold and wouldn't stay up there.

2. The netting is a complete pain, it snags on anything and everything.


With the 170mm of fibreglass in place the 40mm thick Celotex sheets were fixed to the bottom of the joists and then all the joins covered with aluminium tape to form a continuous vapour barrier.

I held them in place with one screw on each edge at each point where they were under a joist. (so about 10 screws per sheet) Probably didn't need to use that many, but better safe than sorry.

I used 100mm screws driven in at a 45 degree angle so the Celotex wouldn't pull out around the screw.


The insulation was followed by a layer of 12.5mm plasterboard.

Some thinking was required here to not only stagger the joints on the plasterboard sheets but also to try and make sure they didn't coincide with the edges of the insulation boards. This was mostly successful, but there are a couple of places were both end at the same place.

One other complication was that the Celotex had been around here for a while and having been stacked not all of it was exactly the same thickness, or compressed by the same amount when the plasterboard was screwed up tight. This has lead to a few undulations, but nothing too serious.


A skim of plaster and the job is complete, now to paint it once the plaster dries.