ss wrote:
I have a rubber wedge for holding a door open, the door has a not very
powerful door closer.
The `wedge` only has the tip that will fit under the door due to low
clearance.
The wedge slips on the floor tiles usually after a few minutes and the
door closes.
Any ideas on how I could make the rubber slightly tacky to stop it
slipping ?

Buy a Lidl door stop next time they are on offer. The weight holds
it in place IME.