Hi Matt I've used this a number of times for both Karndean and Amtico installations - bought from Karndean (they call it Versilay but same thing). It is a very good product and I used it mainly over quarry tiles where there was a damp issue. I didn't want to lift the tiles because of the uncertainty of what is underneath. Just put down a dpm (plastic sheet) and the Versilay on top. It gives a good sound surface with excellent insulation and sound deadening. It also takes care of any minor imperfections in the sub floor, you can lay tiles straight on and it's quick to install. The drawbacks - you are supposed to leave an expansion gap with both the Versilay and the tiles you put on top which is ok if you are going under kitchen units but you have to cover any other expansion gaps. If you get a problems after, eg. leaking washing machine then it is awkward removing damaged boards and replacing them due to the way they are installed. It is not cheap - about £12 sq.mtr but can save time on preparation. I've also used them on floors where some idiot has gone crazy with bitumen and laid it so thick it needed a digger to remove it.
whats your views on leaving expansion and fitting say 'karndean' on top? surely if the subfloor expands it will pull gaps in the karndean?
Yes - you are supposed to leave a gap for both the versilay and what ever goes on top. On a couple of the jobs I put a minimal amount of beading because they were large areas, on one they were having new skirting anyway and on a couple more I didn't leave any gap along the skirting but left a larger gap under the kitchen units. These were smaller jobs so although I've had no comebacks yet I did take the risk!
Only second hand info but im sure someone said they had problems with joints showing thru thin flooring, might be wrong, just thought id add it, i saw it demo'd at interbuild along with some of the lads on this forum, looked a crackin idea, however not sure id be "risking" anything with karndean ect! Better safe than sorry in my book.
