On Monday, 22 October 2018 16:00:13 UTC+1, alan_m wrote:
I have a enough cloud 7 11mm underlay that has been lying around for the
past 2/3 years that I can use. I'm thinking of using this under the
carpet either stapled down or glued down.

Has anyone had any experience with this arrangement.

Yes, I carpeted two bedrooms with cheap felt-backed carpet about 10 years ago. I too used cloud underlay (cloud 9 in my case) which I stapled to the floor. I stapled lining paper to the floorboards first, under that.

I did use gripperrods all round the edge of the room, which worked fine with the felt-backed carpet.

The finished job looked and felt great - quite sumptuous, especially given the negligible cost of the carpet