Storing Wood in a Subtropical Climate

Thoughts on how to keep air-dried lumber sawn on site from decaying while stored for a season or two — in Nicaragua June 22, 2012

I will (hopefully) be traveling to Nicaragua this winter to help my in-laws saw up some boards to build a small house on a piece of property my mother-in-law is acquiring from her family.

It's in a pretty remote town so shipping in lumber is pretty expensive. We will be falling a few trees and using a mini mill to dimension everything, probably peel some poles for the uprights. We will not be using the wood for at least a year and during that time it will be pretty much unattended. There is family that could keep an eye on it but my in-laws live a five hour's boat ride away.

So what I am looking for is advice on building a temporary storage for the pile. I'm comfortable stacking wood properly but am unsure of how much air space should be left between the pile and the roof. Also, should the roof be painted white to reflect the heat? All four sides will just have chicken wire to keep out the big critters. Are there any ideas or potential problems that can be avoided?

Forum Responses
(Sawing and Drying Forum)
From Gene Wengert, forum technical advisor:
Termites and theft will be two big issues. A watertight roof with a two foot overhang will prevent decay. The roof needs roughly the same space as two stickers. End racking might be best with a roof, but the bottom ends need to be elevated so they are not excessively wet.

From the original questioner:
Thanks Gene. Theft will not be a huge concern as half the town is related either directly or through marriage to my wife. There are several that are well known/respected that could keep an eye on things. I said the wood would be unattended in the sense that nobody will be monitoring moisture content or restacking the pile. "Borrowing" might be an issue so I just plan on building the structure in a way where it has to be completely disassembled to get to the wood. Termites were on my mind as well, but hopefully we will be cutting Honduran mahogany, cumaru or Spanish cedar. I was also thinking of mulching the entire area with mahogany saw dust. Does that make sense?

From Gene Wengert, forum technical advisor:

Not sure about mulch as they have flying termites, while we do not here in the US. Keep the rain off if possible.

From contributor Y:
We use Home Defense from Home Depot here. It works real well to keep the PPB off the pile. I am unsure about Termites long term. The dry termite maybe, but fromosian are evil buggers. You may have both like us. Both swarm in the summer at dusk and are attracted to light sources. PPB will come out right about beer time and you will see them hovering around the fresh sap wood. Sometimes dependent on wood type they will go deeper than the sap wood. They are really hard to impossible to get rid of – around ten times the amount of poison that they use to fumagate your house for PPB over termite. It’s also really expensive and they still can hatch eggs for up to five years. There will probably be other borers local to where you are going.

You need to spray heavily if you’re going to leave unattended - stickers too. Don't spray the layers in the pile after you lay down the next set of stickers, they will crawl under every sticker and there will be severe damage 1" wide x 48" long every 18". Spray the stickers too. They only cost about .30 each, about 80 per 4x8 sheet.

Mulching and slash piles are bug havens. I would keep the area clean and dry, if not on a slab then crushed stone, and with or without that still juice the whole area under the pile with the same Home Defense. It will kill most every crawling bug and its family for four-six months between treatments. If you can edge your material and discard your sap wood/bark you may be ahead of the game with bugs. The latitude where you’re going is similar to me. The wood will dry quick 4/4 AD in four months, 8/4 in twelve months (plus) 16/4 eighteen months and counting, for hardwoods that is. If you can keep it out of the sun with big overhangs, and maybe put a layer of plastic on the ground that might help too.

From Gene Wengert, forum technical advisor:
As I mentioned, they have a different termite in Central America than we have in the US. It is called the dry wood termite and it does not have ground contact much of the time so Contributor Y's suggestion for a spray is not appropriate in this case. If you are using a hardwood, the PPB can get into the wood of some hardwoods in CA, but many species have natural resistance. They hatch in a few weeks in your climate and not years as we would see in the North American climates (seldom over one year). The locals can guide you on the correct species to use.

From contributor Y:
Here in Hawaii we have both Drywood Termites (also known as flying termites) and Subterranian termites, the Fromosian Termite. Both fly and swarm. PPB is a major concern here especially for people who sell flooring. I have friends that sold flooring with PPB in them and had to have whole finished floor pulled up and replaced as it was less expensive than exterminating the entire structure. Most people here believe they will not inhabit dry wood but I have seen fresh PPB dust in 150 year old furniture here that was bone dry indoors.

The subterranean termite needs a water source. They also can make mud trails and crawl up other materials to get to what they like to eat. At a lumber mill I frequent they have a table with Eucalyptus Robusta legs and a top from a softer local wood. The mud trail went from the ground right up the side of the legs and into the underside of the tabletop. This was under a cover on a slab with a moisture barrier. I believe there was a leak in the structure behind the table. I replace half my house due to Fromosian termites, the other half because of dry would termites. I had mud trails all the way up on the rafters. They treat them with Fripinol and other similar chemicals that can affect the entire colony. The dry termite or "flying" can re-inhabit because they do not communicate with a colony like the Fromosian do. There’s also some bug, beetle, or worm that gets into Spanish cedar and mahoganies as I have seen some sparse insect damages in lumber I have worked in the past.

From the original questioner:
I'm starting to think it might not be worth the risk. I thought it would be relatively easy to avoid infestation if I selected the proper hardwoods but sounds like that is not the case