Lumber Cutting & Drying (# 5)

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Lumber Cutting & Drying (# 5)

10/3/2008 6:04:00 AM by tikka

Stacking, Drying and Long Term Storage of Lumber

I have made this part of the series in 2-parts as it was getting a little long - it will also give you time to cut and stack some lumber. The final part of this seies is blog #5b

Now that you have managed to mill the lumber into the required dimensions, in this, the last blog of the series I will discuss the stacking, drying and storage of your valuable lumber.

The first thing we have to do is find a suitable site, there are no hard an fast rules about this, but ideally:

Level ground, that does not retain water (not the middle of a pond or swamp).
Not in direct sun - we do not want the wood to cook on the outside, whilst it is still wet inside.
A good breeze - the site should allow for the air to pass through unhindered.
Not in the way - The lumber is going to sit in this location for a year or more, so try to site it where it does not have to be re-stacked and moved, at least until the lumber is below 16%.

Preparation of the base - this is probably the most critical part, because if the base is not level, then the stack of wood is not going to be level, and could topple over.

The ground should be firm and dry, preferably with shingle or stones, to improve the drainage and reduce the moisture content in the vicinity of the stack . I usually make my stacks 3m (10’) long and 1 to 2 m (3 to 6’) wide.

I start the base, by making some piers, usually out of old bricks or concrete blocks, these to about 25 - 30 cm (10 to 12" high.

I like to top and connect the piers with some planks, and 15 x 15 cm (6" x 6") lintels made from fir or pine.

This is the time that I level the structure by using hardwood wedges to raise or lower areas and make sure that everything is stable and level, with absolutely no wobble.

Once you have the base level, then it is time to start "sticking" the pile. The sticks I use are made from birch, but any medium hardwood is OK stick should all be of the same height and width, I find that ¾" square is pretty good. The length of the sticks depend upon the width of the stack. The spacing of the sticks I found that 25 cm (10") for 2/4 & 3 /4, 30 - 35 cm (12 - 14") for 4/4 & 6/4 and 40 to 45 cm (16 - 18") for 8/4 and larger lumber. It is important that you ensure that the stacks are aligned vertically, so that the load is transferred from the top to bottom evenly.

I usually start with the larger (thickest pieces) on the bottom of the pile gradually decreasing the thickness of the lumber as I go higher in the stack. This has several advantages:

The thicker lumber requires more weight to keep it flat than the thinner lumber.
The thicker lumber is not so difficult to manoeuvre at lower heights. Handling a 8/4 x 12" x 10’ board (about 55kg/120lb) , when freshly cut at 5’ above the ground is not that easy.
Placing the thinner planks on the top of the stack, requires less ballast to keep it flat.

I would limit the stack height (excluding ballast) to about 1.5 m (5’), after this height it becomes difficult to position the planks.

The lower boards (white) are Birch and pine, cut this year. The darker wood atop of this is Tuomi, which was cut and dried last year. ( I have no space inside for this at the moment, so I am using it for ballast). On top of all the good wood is the pieces left over from squaring the wood. It is important that you get some good weight pressing down on freshly cut lumber, in order to keep it flat.

This picture shows the Tuomi (Bird Cherry) I cut and dried last year. Note I used pallets for the base, which was not ideal, but it did work.

The entire stack must then be covered to prevent the rain from penetrating and sitting on the wood.

The coverers used are new and a little too large, but they kept the wood dry as it just started to rain. I will adjust them slightly so that the sides are not so long, allowing air movement from the sides of the stack.

You can use just about anything to cover the stack, plastic, tarpaulin, metal or plastic sheets, just so the water does not collect on the top or permeate through.

The drying time for the lumber will depend upon:

Species of wood
Thickness of the planks (1 year,for 1")
How wet the wood was when cut
Humidity and temperature conditions locally
How good the air circulation is.

Once the wood has reduced its moisture content to below about 18%, then your wood is pretty safe against most insects and fungi - If you are going to dry your own wood, then I would suggest you buy or make your self a good moisture gauge/meter. It will really help to keep your hard work and investment in good condition.

I find that the best drying time is April, May and June, where the humidity get to about 25% in the afternoons most days, the winter months, November through March, although the humidity is not that low, 50 to 100%, the temperatures stay between -5 and -30° C (23 and -22° F) and the moisture is also drawn out of the wood during this period.

The remainder of the time July to November are pretty humid, but we do have good breezes, which pass over the wood, drying the surfaces.

This concludes the stacking and outside storage, in the next blog (#5b) I conclude this series by telling you how to further dry and store your lumber inside.

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