Did a search and can't find any threads here relevant to Exped down mats, so thought I'd pass this tip on. It should apply to any airbed/mat.

Punctures are usually caused by little bits of grit or detritus which are either a little difficult to spot when laying out a mat in the tent, or get brought into the tent on clothing/footwear and find their way under the air mat. Apart from sweeping out a tent regularly and keeping things clean, which is sometimes difficult, the ideal thing is to create an extra layer between the mat base and the tent ground sheet, and especially to try and stop the slippery surface of the mat moving about, which usually causes the punctures.

Over the last few years I've been using a strip ( exped downmat L size) of rubberised anti slip material, the sort that comes on a roll and which can easily be cut to size ( not a solid rubber mat) and is used either for stopping rugs slipping about on shiny floors or for stopping crockery moving about on an uneven/unstable surface. Not only does this stop grit and dust getting under the mat, it stops it from moving about.

The anti slip rolls up small and there are ( of course) no weight issues! Anti slip material is usually available in larger supermarkets and in DIY superstores.

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