Project Shed

[Steve]

I built a concrete workshop at my last house, I made a few mistakes that you might bear in mind.

I laid a thick concrete base, with a plastic moisture barrier inside. This worked well, except that I laid it before I had decided which workshop to build. It was 12" bigger all around than the workshop, which allowed water to puddle on it and seep through the concrete to make the floor damp. I had to waterproof all the "apron" of concrete to stop it.

Secondly, the workshop I bought came with a fibre/concrete corrugated roof with clear corrugated plastic panels for light. This also proved to be porous in the fibre/cement, and the plastic panels always had condensation on them. I had to paint the roof afterwards, and even with bubble wrap inside the clear panels I still got condensation. The panels also proved quite fragile when tree branches hit them. If I had to do it again I'd choose a flexible onduline roof with no light panels.

Third, my workshop came with a galvanized steel door. Bad idea. Lots of condensation on it - wood is better.

Fourth - Dust. I should have covered the floor with something, a vinyl would have been good, or a good quality two-pack floor paint. I was in too much of a hurry to get in to let the floor dry sufficiently to paint it, and suffered from dust for ages. I think I made the top layer of concrete too wet, looking for a flat surface, and this released a lot of dust as it wore. Make the top surface a stiff mix and beat it flat, or apply a proper self-levelling compound.

I hope this is useful. I loved my workshop, and it was an incredibly useful addition to an urban house.