Acclimatizing SPF Lumber for furniture.

[Rahul Srivastava]

I am building rustic coffee tables out of SPF lumber. I start building the rustic coffee tables immediately after purchasing the lumber from the home depot. When the project is finished I am having them sit on my garage floor, while I wait for a customer to come and purchase the table. Sometimes they are sitting for 2 or 3 weeks.

I have noticed that when I bring the tables to the customers house the coffee tables are not sitting flush when on hardwood flooring, luckily the customers have all wanted the coffee table in their living rooms that have carpet or rugs, so the table has some cushioning and end up sitting flush with the floor.

What I am wondering is how to I ensure that the coffee tables are level no matter what? Should I wait for the wood to acclimatize to my garage? If so, how long should I wait? Also how do I prevent the wood from warping if I have the wood sit in the garage for long periods of time. The reason that I build the projects immediately after being purchased from HD is because I buy the lumber relatively straight.

[Mike Chalmers]

First of all, I will state, for the record, that I live in Canada. The quality of the lumber and how it is stored may be different in the US, but, I doubt it.

Most lumber from a building supply store is going to have a fairly high moisture content. The boards they actually keep in the store proper may not be so bad, but the lumber stored in the yard will high. This "building supply" grade lumber is going to twist, warp and, perhaps split. Not much chance of it doing anything else. It should sit in your shop for at least two weeks, preferably longer. That being said, you will probably have to true the lumber up to take the twists and warps out, and a 3/4" piece will be down to probably 5/8" (if it wasn't already).

Even properly dried and stored wood will move as it acclimatizes itself to your shop, but may only move a little. Best way is to buy rough and mill to desired dimensions after time spent curing in your shop.

My opinion based on personal experience.

[John Sincerbeaux]

The first problem is you're not really "acclimizing" the wood to the environment you are intending the wood to be placed. You should acclamize the wood "indoors". Secondly, I would set the table on a hardwood (level) floor at YOUR house prior to delivery to your customer. Make any adjustments prior to delivery.

[Curt Harms]

I think construction lumber/SPF is dried to around 19% moisture, just dry enough that it won't support mold growth. Kiln dried hardwood is typically dried to <10% moisture. How wood is stored post drying matters too but softwood has a lot more moisture to lose than hardwood. On the plus side I suspect softwood will dry faster than most hardwood. I found a moisture meter a worthwhile investment. How fast wood will dry depends on temperature and humidity. Wood will dry more quickly stored in 70o F. and 30% humidity than it will stored at 500 F. and 75% humidity.

[Lee Schierer]

In addition to the higher moisture content of SPF lumber, there are several grades. The typical big box stores get the lower grades that they sell for a low price. Typical lumber at those places is center cut pieces with the pith or right next to the center of the small tree it was cut from. This inherently makes it less stable. Buying the better grades will reduce your warping, twisting problems to a degree, but will increase your material costs. I would advise that you get a moisture meter and plan on stacking and stickering your lumber for 6-12 months before it reaches an acceptable moisture content for furniture making.

[Danny Hamsley]

I agree with what has been said. 19% moisture is too high to build indoor projects with. The wood needs to be dried to below 10%. You can do that by stickering it in an out of the way place inside your climate controlled house, not the garage. A good moisture meter will tell you when it is ready to use rather than guessing.

[David Kumm]

If there is a local kiln, I would put lumber in for a partial charge and reduce % to <10. It will take a long time to dry out on it's own- if ever. Dave

[Jim Dwight]

This will not solve it for you except possibly occasionally but I've noticed that the construction lumber sold at the big box stores is dryer in the early spring than at other times of the year. I don't think it sells as fast in the winter and thus spends more time indoors and the air is also pretty dry. But it is still prone to being somewhat higher in moisture than you really want for furniture, as has been noted. I've used it for years, however. If you make some allowances (drawer gap allowances are likely to open up, for instance) it works. I got rid of a bedroom set in my hopefully last move in 2013. That furniture was made of construction lumber in an apartment in Philadelphia about 1980. So it was 30+ years old and had survived 4 moves. It wasn't fancy but worked for us well. My first furniture project in this house was some 16 inches deep shelving for my wife's office/craft area. She wanted pickled pine. Shelving boards were more effort than plywood but was what she wanted.

[Peter Quinn]

Another problem you are not going to get away from...this wood is not very high quality. Its barely #2 structural grade on a good day, some big box wood is even lower, stop its really wide growth rings, active knots, wane, sap, etc. This is a far cry from KD FAS furniture grade lumber. I would plan on buying some t nuts and leveling feet, counter sink these into the bottom of the feet, a whole set will only add a couple of bucks to your cost plus installation labor, this will allow adjustment over time to any floor, and I'd be surpassed if that stuff ever stopped moving. I'd suggest you moisture meter it upon receipt and plan to air dry it for minimum 6-9 months sticker and with some air flow. I to have bought studs late winter that were below 10% moisture, and I have bought them from a fresh bunk that were nearly 20%...thats not workable except for building walls.

[Tom M King]

Wood moves. That wood moves a lot, and in unpredictable ways. It's sawn, dried overnight, milled to size the next day, and banded into bundles, so it has all sorts of stress in it. What you buy as straight today, might not be next week.