We just built a mini goat barn using pallets as the walls. It's about 10'x19' if I'm remembering correctly. We had the walls up for months before we decided on a roof. In the end we gave in and just bought some 2x4s for rafters and used metal roofing sheets (about $20ea at Lowes). Cost about $200, but not bad since the rest was
free (except hardware). Finished about a month ago and already realized it's not water-tight so we are going to attempt to seal it.
We also built a
chicken coop out of pallets, 4'x16'. Broke down a bunch of pallets to fill in the gaps in the pallets and painted it yellow. We used OSB (recovered from a construction site dumpster), covered with tar paper and shingles (both found at a
yard sale) for the roof. That one's not entirely water-tight either but it only drips in a few places and it has a dirt floor so not a big deal. Been up since last summer so I figure we will get our money's worth. Ugly as hell though.
A lot of the stuff we use for our projects just comes from being patient and keeping our eyes open. I'm not afraid to stop and pick something useful up off the side of the road or ask a construction worker if I can haul of their junk either. Construction sites are incredibly wasteful and will throw away a perfectly good 2x4 because it has a knot in it or they are done for the day and figure they can just open a new package of nails the next time they come to work so they throw away the open one.
I would love to hear anybody else's ideas since we have an endless supply of pallets and we are always needing new
shelters. The roof is always the most difficult...