Is there such thing? They want the thickest underlay under their quickstep vinyl click I usually use their 2mm underlay but if there is thicker compatible underlay out there that's allowable then I'm all ears.
What about one of the self adhesive vynil underlays, i think uzin do one with the self adhesive on the bottom, don't know about thickness or cost
I always advise this but they already got the flooring themselves and the builder was going to glue it down to the floorboards even though it's a click system and needs an underlay. They want something with a sound proofing as best as they can so looking for a solid dense rubber
