Building a shed.

[simonm]

I was looking at steel roof sheets on ebay £1.75 per foot running 3ft cover done for 30 years.

 

Steel sheets are really good but they get lots of condensation on the underside despite volume of airflow going through them. i have had this problem! not such an issue for us as they are keeping logs 99.9% dry. But if its for a workshop i would definitely buy the insulated ones

[mixedangased]

Always a pitched roof with steel sheets for me, more likely to keep the water out and easier to construct. Plus extra storage for ladders, timber etc.

If I'm worried about condensation I usually put a layer of tlx gold underneath. Not cheap but great stuff.

 

flat roofs ok, but i fibreglass mine,pitched too.

as for nail gun forget it ,crap fixings imho, unless ribbed nails,screws every time stronger and easier to get apart again if needed.