Have your home-made hives shrunk?

[ugcheleuce]

[also posted in the UK forum]

Hello everyone

I'm currently making a prototype hive from very, very cheap Norwegian spruce flooring planks.

If I understand correctly, the planks are still fairly "wet" and will probably shrink a bit over the course of the year (the store where I bought them didn't say so, but I weighed the wood and consulted some tables, and one of the planks bled a little bit of sap at the one end).  I would not be surprised to see the hive reduce 8% in height.  Fortunately, the way the hive is designed, I expect the walls to shrink uniformly, and only in height.

What are your experiences with home-made hives made from cheap wood, specifically regarding shrinking?

The hive is 227 mm tall, and an 8% shrink would result in an 18 mm shrink.  So I'm actually considering increasing the bottom bee-space by 18 mm, knowing that I'll have brace comb in the first year, until I can see what the boxes do, and then next year sand down the box to the design height.  What do you think about that?

Thanks
Samuel

[Vance G]

Your assumptions are fairly accurate.  The sap oozing is not where the lateral loss comes but from the water loss.  Think of the wood fibers as long tubes each holding some water.  The water evaporates and the tubes and the board shrink.  Fortunately, they shrink laterally  and not lineally.  When I built my deck, the flooring was pried tight together and there is now a 3/8" gap between the boards.  I built a pine privacy fence and put the boards tight together.  It rained for a week and the deck screws all broke as the wood swelled.  I put the fence back together and now years later, a half inch gap exists between the boards. 

[ugcheleuce]

When I built my deck, the flooring was pried tight together and there is now a 3/8" gap between the boards.

You know, this got me thinking... (but thinking can be dangerous).

The planks are meant for flooring, so they have tongue-and-groove joints.  There are three planks on top of each other in each sidewall (i.e. two joints between the planks).  The planks in the front/rear walls are also meant to be horizontal (with the joints running horizontally).  But: if I could turn the planks in the front/back walls by 90 degrees, so that they are vertical, so that they won't shrink in in the same direction as the sidewalls, then maybe the sidewall planks will shrink by "opening" at the tongue-and-groove joints instead of shrinking at the top and bottom of the hive box.  If they shrink very badly, I may have to fill up some gaps, but regardless of how badly they shrink, the hive box won't become less tall because of the shrinkage.  It does mean that I would have to use nails instead of screws to join the sidewalls to the front/rear walls.  And I'm not sure if that means that I would have to use less glue on the sidewalls.

[bbbthingmaker]

Green wood will shrink as it dries.  Some woods more than others, and not necessarily at a predictable rate.  As a general rule lumber should be air dried, protected from the weather, one year for each inch of thickness. Building with green lumber could cause a lot of problems later.

[rwlaw]

I agree with bbb, every piece of wood will act differently drying. In the old days wood was milled to reduce the warping/shrinking of the board, now days it,s milled so as to reduce scrap. It depends on the location of the board in the log, let it dry, it'll save some hair (or nail) pulling in the long run.