I’ve got a variety of roofs on my hives. Some are homemade, covered with roofing felt or damp proof membrane. I have a number of disappointingly flimsy ‘seconds’ from Thorne’s purchased at about £18 each from trade stands at the National Honey Show or Spring Convention. Finally, I have a few beautifully made ones from Peter Little of Exmoor bees and beehives (highly recommended if you don’t want to make your own equipment). My DIY roofs and the cedar ones from Peter are strong, but they’re also quite heavy. It’s not as if there isn’t already enough heavy lifting to do when beekeeping …
I use fluted polypropylene such as Correx or Corroplast for a variety of purposes – landing boards on Kewl floors, Varroa trays, fat dummies, temporary crownboards and – I fear in the future – as SHB traps. I usually scrounge abandoned ‘For Sale’ signs, advertising boards or political posters, but these are rarely larger that A2 in size. I recently bought (from eBay) five sheets of 1.2 x 2.4m 4mm Coroplast for about £12/sheet (delivered) for another project and built some roofs from a spare sheet. I can get 8 National roofs from a single sheet i.e. each folded from a 60x60cm square, making each cost about £1.50 (plus a few pence for tape or glue).
If these withstand the rigours of the 2014/15 winter I’ll post some simple construction details in due course (it turns out there are tricks to folding and gluing Correx … you’ll need a pizza cutter). Correx roofs aren’t an original idea … Jon from the NIHBS, the acknowledged Correxmeister on the SBAi forums, has previously posted details of both roofs and nuc boxes built from election posters and yards of gaffer tape.
At the very least these lightweight roofs are likely to be very useful on bait hives which are both temporary and usually moved soon after being occupied.