Have a Therm-a-rest with a hole in it, bought a kit then read the instructions... not so clear I thought, so I Googled it. After reading a couple of articles I think I got the gest of how to do it. So for your reference I thought I'd write up my way of doing it, based on what I have read.
Finding the Hole.
Easy one this, you will just need a bath with enough water in to partially submerge the mat.
Inflate the mat to its fullest, submerge a section, give it a good squeeze and then look for bubbles.
Once you find bubbles you've found your hole make note of it and continue inspecting the remainder of the mat in case there is more than one hole!
When you are satisfied you have all the hole marked or noted (I don't like the idea of marking with a pen like some articles suggest) let your mat dry properly ready for the next stage. Have a cup of tea while your waiting.
Cleaning the Damaged Area
Use the alcohol moisty wipe to clean the area thoroughly to remove and oil, or dirt that may impede the glue/patch from sticking effectively.
After you have cleaned a generous amount of mat allow the area to dry.
Apply Glue dot.
I've cut one of the glue dots and heated it my hands, seem to make it more malleable?
Peel off one side of the glue dot backing (the one with the writing) and then applied the glue dot over the small hole and pressed firmly down.
Leave to sit for a short while then peel off the backing to leave the glue as below.
Carefully cut one of the material patches supplied so that it is 50% larger than the glue area. I used the thin one as the mat is a light weight version. And ... er.... Cutting Fu not so strong with this one....
So done, leave it for few hours before using.
So there you go, my interpretation of how to repair a Thermarest.
Hope this helped some people.