There is a simple reply to this David and you are right a hard paper was placed under the underlay especially the old foam backs,but with the onset of better underlays and better flooring and now felt backs instead of foam backs it was just not needed anymore and it was also not beneficial as it made the underlay move more than it should ,and also cost ,most customers dont want to pay for felt or paper on top of dodgy floor boards ,and of course there is not a lot fitters can do about gaps under skirting boards. Re making holes in the underlay ,I think you misunderstood me ,a spike from a stretcher would not imo make a hole in underlay even fully extended I would be very surprised if that was the case as the spike would just penetrate the hessian backing ,unless like I said before it was a very worn carpet or felt back ,foam back .If you got a piece of underlay say tredaire which is rubber backed or even the old type felt ,even cloud nine which is made up of foam and punctured a hole in them ,they would go back to what they were before ie the hole would close up enough for nothing to come through .We live in a throw away society and the carpet industry is no different and they say most people change carpets every 7 years and this is the reason they are trying to make them more environmentally acceptable .Most customers couldnt give a damm about what is hidden under their carpet and if you advised them about gaps etc and it would cost an extra etc etc they would turn their nose up mate .