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I’ve been wanting to do this for a while, but for quite some time didn’t have a clear plan. Recently however it occurred to me that it would be possible to make a pair of five-frame nucs from PIR insulation board that could sit side-by-side under a single national roof.

I made two PIR boxes from 25mm PIR (for the sides) and 50mm PIR (for the ends), gluing them together with foaming PU adhesive reinforced by bamboo skewers. The external length of the sides was 460mm — the full length of a National brood, and the ends were 230mm, giving internal dimensions of 360mm by 180mm. Five Hoffman frames should be 175mm wide (35mm each), so allowing for a bit of propolis they should be a neat fit.

Obviously PIR isn’t going to stand up to the rigours of being poked with a hive tool, so the tops and bottoms of the box are made from timber with a rebate for the frames to rest on. To stop bees “exploring” the PIR, all the bare ends are wrapped in aluminium tape.

I’m into insulated crown boards, so they’re made from some scrap weather-resistant ply with a 50mm PIR insert.

The floor is an “underfloor entrance”

Finally, to protect everything from the elements I found some offcuts of car wrap material online and wrapped the boxes in a selection of colours.

And here they are, six nucs sitting under three roofs (with a couple more spare roofs on top).