There are hundreds of things out there but can anyone recommend one that will stop the hall carpet going for a walk ?

Screws or nails are not an option.

glue? double sided carpet tape?

Sorry, not made myself to clear, carpet (rug) on a carpet if you know what I mean.

Velcro strips on the back?

I have this grip mat thing underneath which I brought from Ikea. Works a treat for stopping it move about and you can still lift it up

It looks like a fookin' huge Shreddie (under the rug)

O

yeah we have a rug on the laminate floor. you get a fine mesh like rubber mat that you cut to a size slightly smaller than the rug. Then lay it underneath. stops it sliding on laminate so should stop it sliding on carpet!

John Lewis do a grip mat for just this job. You buy it my the metre and it works a treat.

G