Help insulating an old summer house

[stev]

Well, not much of an idea what I'm doing, so any help will be appreciated. So far I've taken off the weetabix boards of mdf or whatever, then a load of fiberglass, and the odd bit of straw, and now I'm left with this:

https://picasaweb.google.com/lh/photo/x8UkQXxdmHIlJklkCyaofNMTjNZETYmyPJy0liipFm0?feat=directlink

I've bought some breathable membrane and I'd like to put that on quite soon, otherwise everything else is just getting wet. The problem is that I really don't want to take the wooden planks off from the outside, as they're quite delicate and will split, please can someone tell me if: 1) it is ok to staple the membrane to the inside of the stud wall, and 2) this would leave a 70mm gap between the membrane and outer wood planks, should/could I fill this with anything, bearing in mind it will be somewhat open to the elements. A pic of the external wall is here:

https://picasaweb.google.com/lh/photo/DcYCbwjnY1eRD6ePDNg1SdMTjNZETYmyPJy0liipFm0?feat=directlink

Thanks v much for your help, I'm just having a bash here and there's no one around to help really!

 

[noseall]

Breathable weathering membrane is fitted externally and is designed so that rain is kept out whilst allowing water vapour from within to escape.

A typical timber construction would be (from in to out) plasterboard, v.c.l., foam board insulation, sheathing ply, counter-battens if necessary, breather membrane and decorative weathering layer i.e. waney planks, cladding, tile hanging, rendering etc.

Your best bet would be to wrap a large (cheap) tarp' around externally then crack on with the inside. We can buy 9m x 6m tarps for aboot £35.