Insulating the Interior

On Wednesday last week whilst I was doing the weatherboards, some of the boys were inside preparing the interior for insulation (which is what we concentrated on doing today).  They had to make sure that all of the walls were all flush for when the Gib sheeting is to be put on it.  In order to achieve this, they had to plane back where nogs or other parts of the frame might be sticking out a bit, so that it is all flat.

This is best to be done before the insulation is done as it can get in the way when trying to plane or get into certain areas.

When doing the insulation we started off with the ceiling first, using 'R3.2 ceiling pads (polyester thermal insulation made by green stuf).  These come in 430x1220 pre cut pads which are 180mm thick.  They are laid on top of the ceiling battens and generally fit so that two can go between each truss.  It is important when we are laying the pads down, that they are not scrunched up and are as flat as possible.  This is because the insulation works from the still air pockets within it - by squishing the pad up (it eliminates the air pockets required to keep the warmth).

The pad's had to lie flat against the ceiling batten and where wiring or pipes were present, the pad had to be cut accordingly so that it could fit.  This was done by using a craft knife to cut through.

We found that the blades of the craft knives constantly became blunt because of the material we were cutting through, so we had to use a sharpening stone to keep the knives at a level where they could cut.

There should be no spaces present where the insulation is, as this will cause poor results with it's insulating capabilities.  Rich mentioned that for ever 3mm gap present 1% of its insulating power is lost.

Whilst doing the ceiling insulation, we also sealed the window frames.  We did this by putting Sika REF 10mm rod packing into the gap around the window frame.  This was pushed in so that it was around 25mm inside the recess present.  This was done so that it sat between the wooden packers already present, and where it was too thin to pack the gap, a double amount was fed into the space.  Once this was done, expanding foam was then injected on top of the packer so that there were no gaps any longer.

When using the expanding foam, it had to be shook for 30 seconds before use & for some of the cans they were only active if the bottle was held upside down.  Some of the cans had multi positions, so it is very important to read the instructions so it functions properly.  This will be left until tomorrow where it should have expanded and dried adequately enough for us to tidy up and cut the excess away.