[Closed] Erecting a steel building for use as a double garage and workshop.

Condensation might be an issue unless you do one of the below:
a) ventilate it really well
b) use insulated sheets
c) use sheets with fleece 'dripstop' underneath (which holds much of the condenstation until the ventilation can dry it off)

We re-roofed our 70' x 30' barn with (c) and so far it's been great but it is well ventilated as well - I'll know for sure how good it is in 6 months time.

I built a yardmaster 13x11 (I think, pretty big anyways) metal shed by myself.

Never again – the structure is only strong once the metals sheets are added and the roof supports are 20 bazillon bits of metal bolted together. You need 2 pairs of hands and a cordless drill/screwdriver to make it in 1 day. There is a lot of wobbling during construction and it’s all quite flimsy.

Doors are awful, in bad storms I put a garden bench up against them to stop them blowing off (loads of ventilation), but despite this tons of ventilation (eves and roofline) the condensation is phenomenal. It’s freezing in the winter and roasting in the summer (far too warm to store my homebrew in).

It’s to go this summer (building a proper replacement) despite it being structurally sound and hasn’t started to rust anywhere as I want a proper shed/workshop that doesn’t have any of the above problems.

A few mates have the custom metals sheds (Including a big one for storing an elise) with the anti-condensation roof stuff and they are much better in most respects – metal is 2-3x thicker (but still not massively secure), a tiny bit of damp on the walls but still roasting hot in summer.

I should add that our barn has brick walls so it doesn't feel like you're inside a tin can.

Parents really roofed their long shed with sheets that had a non-drip insulation treatment. Seems to be working fine as my Dad is out there more now he's retired. Stone built walls and fairly airtight.