UFH.....Celotex or 200mm of roll insulation ??

[aspley]

What floor/ceiling construction benefits from net lawn?

The OP is not being very informative. A curious mind like mine then wonders how 200 mm of glass fibre is possible but not 75 mm of cellotex!

Tony

Thought I had given you enough info but John D is correct.....this is a farm house renovation and original spec, whilst more than adequate , does bring with it a few challenges where a bit of ingenuity is called for.

I like the net idea but am now wondering what the issues are with wiring which will be run below the insulation.

 

[JohnD]

if the cables only have insulation on one side, they will be able to lose heat. But it is important to prevent the insulation being able to sag round the cable. You can put a bit of plasterboard between the two to prevent it.

If the cables were run in a warm space then again they would overheat. They must not be allowed to touch hot pipes or electric heating, or they will prematurely age and crack, and in some cases the copper wire can "swim" through the heat-softened insulation to the surface.

Expanded polystyrene must not be allowed to touch PVC cables as it will leach the plasticiser out and they will go sticky, hard, and crack.

As a rule of thumb, insulation round cables means you have to halve their current-carrying capacity. This is OK for lighting cables on a 5Amp or 6Amp circuit, but not for most other circuits. Immersion heaters, storage heaters and electric showers in particular usually load their cables near the limit, and they will overheat if insulated.