Pond Boss Forums POND CONSTRUCTION Selecting a site Boat launch and dock construction

Good work, Grasshopper.

On metal roofing: Normal protocol is to use 2"x4"s (called purlins, today's $2 word that I didn't learn until my 4th barn), going perpendicularly across the trusses/rafter boards, to hold up the metal roofing, which itself is perpendicular to the purlins. Typical purlins spacing would be 2' apart, perhaps wider in areas with a lower expected snow load or for steeper roofs. The 2"x4"s are of course stronger in this role if oriented vertically (the 4" going up and down, the 2" contacting the rafters and the roofing). Concerned amateurs nail or screw the roofing through the raised ridges onto the purlins, barn #4's "professionals" ( :rolleyes: ) screwed it through the flats (we were a little unhappy about that - it may be OK since it's screwed, if nailed it would be a nightmare).

Here's the best digital picture I could find of installed purlins and roofing (a ltttle blurry because the building was not the main subject). You can see the siding on the wall better and it is put on completely analogously to the roofing, other than the orientation of the 2"x4"s. I hop this helps.