got a self inflating mattress a few years ago half way through the night it always becomes flat put it in water and looked for leaks but not seen any any ideas anyone???
mine was the same. i found tiny holes by blowing up the mat - sticking it in the water then squeeze the mat to increase pressure inside by rolling it or folding it.
WIth something as big as a mat it could be tricky to see the puncture. Unless you actually take it swimming (possiblility in weather like this?) Could the valve be open or faulty?
OR perhaps you have a mischievious sleeping partner?
In reply to shumidrives: To blow self inflating mats that refuse to inflate up, you put your lips to the value, take a big breath and mutter the words "Self inflate" as you blow into the valve!
In reply to shumidrives: Mine does the same, i fear it is either the material seeping or the valve that is knackered, when i remember i will take it in to get it looked out, but i ALWAYS forget!!!