Someone (cough cough) screwed through a water pipe under the floor boards in my mother's house. It's a 22mm copper pipe that I'm pretty certain is running hot water from the combi boiler.

I removed the screw and replaced it with a shorter and slightly thicker screw to plug the hole. The screw itself did a pretty good job of stopping the flow of water (to something like a few drips a minute). The pipe runs parallel to the floor boards but has a 90 degree turn a short distance after where the screw went in to the pipe, which means pulling the pipe up and getting a pipe cutter in to replace a section of the pipe would be a massive pain and involve me pulling up at ton of floor boards, which I really don't fancy doing.

So, I got some epoxy "Quick Leak Repair Putty", specifically this stuff:

I put two layers of this stuff over the screw and it seems to hold perfectly, no issue with water pressure and no drips or movement in the putty.

Here's a picture of the pipe with the putty:

It's been there for a week or so now (with some heavy use of the heating… it's cold) and it seems pretty solid to me. I spoke to a few people though and a plumber friend said in no uncertain words "Never, ever use that"… which seems to be the general consensus. I'd rather not rip up half the floor and I'd rather not pay through the nose for someone to essentially cut out a piece of pipe though.

So my question; How temporary or not is this fix?