The lumber has arrived and I want to start erecting the frame for the machine hall, but I need special sealant for the sill I've set my sights on Paroc's model called XSS 015 which has an upturned edge of plastic that you fold up. The problem is that I can't find anyone who seems to have it on the shelf, and the local builders' merchants must special order 2 rolls since they are delivered in a bag of 2, price with shipping 2500:- !!!. I only need one roll of 40m! I'm considering if I could put together my own variant for a fraction of that cost: if I were to take a cheap "sleeping mat sill sealant" closest to the concrete, then aging-resistant plastic closest to the wooden sill, and make each side fold up a few decimeters, one on the inside (to seal the sill against a wash edge) and one on the outside. Of course, weather protection, battens, and sheet metal facade on the outside. Attaching a small picture, what do you think of this? I want to avoid lay block masonry for various reasons.
The plastic should last better due to the sleeping mat sealant against the concrete, floor heating will be used so any water will probably dry up pretty well and quickly? The only problem might be the expansion bolts that must go through, sealing compound in the hole after drilling?
Googled around a bit and found two alternatives to Paroc: T-emballage T-syll super and Isola syllmembran, has anyone tested any of these? There seem to be a few products that have what I was thinking about, but they seem quite hard to get hold of??.. :/
I've set my sights on Paroc's model called XSS 015 which has an upturned edge of plastic that you fold up. The problem is that I can't find anyone who seems to have it on the shelf, and the local builders' merchants must special order 2 rolls since they are delivered in a bag of 2, price with shipping 2500:- !!!. I only need one roll of 40m! I'm considering if I could put together my own variant for a fraction of that cost: if I were to take a cheap "sleeping mat sill sealant" closest to the concrete, then aging-resistant plastic closest to the wooden sill, and make each side fold up a few decimeters, one on the inside (to seal the sill against a wash edge) and one on the outside. Of course, weather protection, battens, and sheet metal facade on the outside. Attaching a small picture, what do you think of this? I want to avoid lay block masonry for various reasons. 
