this is my kinda area, i work for the mark group, we insulate lofts and cavity wall as well as renewable energy etc, we wont touch a loft that has been sprayed like this, basically a loft needs airflow in it to stop condensation etc building up, and we have found that by spraying the whole tile area that it reduces the amount of airflow considerably, and therefore increases the chances of condensation, especially if you have a low roof pitch, its also a damn site more expensive than just laying standard 10" loft insulation which does the same thing. in fact it proberbly insulates you house better. think of it like this, by insulating your tile roof internally then your stopping heat from escaping through your roof, in effect your heating not only your house but your loft too as heat will always rise untill it cant rise anymore, but by insulating the loft floor your actually putting that heat barrier in before the heat travels into the loft.therefore your just heating the rooms you want to heat. and to top off my sales pitch
a semi detached 3 bed house will cost you £169 to have it supplied and fitted because of the goverment grant thats available, in fact if there is anybody in your property thats over 70 or on a benifit then its free! go here to find out more
www.markgroup.co.uk. p.m me if you want a survey done there free aswell!
