Insulation

morgansmummy

Apologies if this is in the wrong place but I'm after some advice re loft insulation.

We are moving to a new property in 6 weeks (fingers crossed!). It's a 12 year old house, which has some insulation, but obviously being MS we want to ensure that we are doing everything we can to be Energy efficient.

The house currently has some insulation in the loft, but it is not boarded at present. We would like to board the loft for storage purposes, and in doing that, My OH has come up with the idea of lining the boards with aluminium foil (i.e. between insulation material and boarding), in order to reflect the "heat".

Now, I can see the logic in this...surely, it will provide an additional layer of heat insulation - after all, everyone suggests that you put a layer of foil behind radiators to reflet heat back in to the room.

However, I have looked into this idea - or at least googled it - and while it seems to us a sensible idea, we have come to a blank. We have seen plenty of specific products, but they seem to be Aluminium backed "cushions". To us (lay persons) it seems obvious, but common sense dictates that if it was that simple it would be advocated by now....

Can someone let me know why this is such a bad idea? We ran it past the guy who was doing a homebuyers survey for our buyers and he just laughed....:o

Obviously, if it's not a bad idea, then I will be straight to the patent office in Newport...unless anyone of you gets there first!!!!;)
Thanks for your help ... and patience if you got this far!!!!:o

MM

jayney

If the insulation is not wrapped and condensed between 2 layers then this is of no use. Recommend you buy multiple rolls equal to m2 of loft in 100mm Rockwool insulation. This inturn may effect you when you are boarding and may have to build up joist width to compensate, it is advised for structual purposes (strength and stability) to criss cross joists.

Hope this helps

morgansmummy

Thanks for the advice Jayney!

I think we will wait until we get in, and inspect what is already there!

MM

chris.west

Hi

I am not sure but is't boarding with foil risky because of all the electrcics running over the insulation?

It is recommended that you have 250mm insulation. New insulation can be laid down on top of old but make sure you do not cover any electrics. If you want to board out the loft then leave a 50mm air gap between insulation and boards. If there is not enough room then run timbers over the current joists to make it. Clip any electrical cables to the sides of the joists then mark their position over the boards.

Boarding straight over insulation so it is compressed will do no good. Insulation works by trapping air so the more space it is allowed the better. Also, running boards over it can lead to a build up of condensatoin and also exert pressure on the plaster of the ceiling below.

I hope this is helpful.