How long does pressure treated wood take to dry? It’s a question that many people have when they are considering whether or not to use pressure treated wood for outdoor projects. Determining the exact time pressure treated wood dries is a bit complicated.

But here is a general idea: how long you should let pressure-treated wood dry depends on where you live and the type of treatment used. For instance, it will take more time to dry treated lumber in Florida or the Southern Coastal States than in more temperate climates.

Read along to learn;

  • How long does it take pressure treated wood to dry
  • How to dry pressure treated wood
  • How to speed up drying of pressure treated wood

How Long does Pressure Treated Wood Take to Dry?

Wait 72 hours for lumber that has undergone pressure treatment to dry completely. We expect that the wood from the lumber yard has been kiln-dried. Check the board for tags and ask the hardware store staff.If not, it usually takes a few weeks to six months before you can paint or cut the wood.

Can You Build with Wet Pressure Treated Wood? 

Yes, you can build with wet treated wood. By building with wet pressure-treated lumber, wood is heavier. And when the wood dries, it contracts, making it possible to warp and splinter. This would also throw off your initial measurements for your fencing, framing, or decking project.

Moreover, you cannot stain pressure treated wood immediately.

How to Dry Pressure Treated Wood  

Use a dehumidifying kiln to dry the treated wood faster. The wood kiln will speed up the drying process. But be cautious not to dehydrate the pressure-treated wood to the point of cracking. Alternatively, lay the lumber flat. Then stack the pressure-treated wood in a crisscross pattern to air-dry within 2-3 days.

By kiln-dried treated wood

With the kiln drying process, you use an oven (kiln) and produce kiln dried after treatment or KDAT wood. In this, temperature, humidity, steam levels, and the length of time in drying the wood can be set.  It will take one to eight weeks for the KDAT wood to dry.

Sticker (stack) your pressure-treated lumber

Stack the treated lumber in a crisscross pattern. With this, they are naturally air dried. That usually takes six months to a year.

DIY Kiln-dry your treated lumber

You can build your own kiln at home. and produce kiln dried after treatment wood.

Lay poly (clear plastic roll) on the ground and then build a frame with 2×4 studs on top of it. This is where the lumber will be placed. Leave space large enough for a standard household dehumidifier at one end, and for a small fan on the other. The fan circulates the air to even out the drying.

Place the dehumidifier inside the kiln and set it to the maximum. You can have a hose that runs out of the kiln and fills a bucket. Have the kiln built on and surrounded by stacked and bound lumber over a light wooden frame that carries the plastic. Seal the plastic with tape.

Place a few access holes to diffuse the dehumidifier’s effect and for you to check the wood’s moisture level. You can reseal the said holes with tape.

After four months, you would have the kiln-dried after treatment lumber.

Interesting Read: Can pressure treated wood be used indoors?

Should you Let Pressure-Treated Wood Dry Before Using?

Yes, let treated lumber dry before you use or paint it. With this, you minimize splitting and warping. Further, wet treated wood is heavy and slippery, making it difficult to handle, fasten, and apply paint.

When damp wood dries, it contracts. And when the wood contracts, it messes up your initial measurements and the paint in your project, may it be for framing, decking, or fine furniture.

How Do you know When Pressure Treated Wood is Dry?

There are three ways to know treated lumber is dry– by touch, applying the clean water test, and using the digital moisture meter. 

Touch test

Scan the wood with your eyes and go over it with your hands (use gloves, please)  to determine if the wood is dry. From here, you can easily determine if it’s still wet.

Water test

Sprinkle water on the wood or board. If the water is absorbed, then it’s dry enough for painting or staining pressure treated wood. But if the surface is still water repellant, the lumber is still wet.

See Also: Is pressure treated wood water resistant?

Digital moisture met

Place the two prongs into the wood. Just make sure the device has been calibrated properly and best to do the test in two different spots to have an average of the moisture content.

How to Speed up Drying of Pressure Treated Wood

The fastest way to dry treated wood is by having it kiln dried by the manufacturer. This takes one to eight weeks. You can also lay the treated wood flat and stack them in a crisscross pattern to air-dry for 2-3 days.

How to dry pressure treated wood without warping

Here are ways to prevent warping during drying:

Don’t over-dry the lumber.

There’s such a thing as over-drying the lumber. This can lead to cracking, splits, and end grain checking. To avoid this, periodically check the wet wood for moisture content. 

Don’t allow partially dry lumber to quickly regain moisture.

Thus, start building your deck or picnic table after confirming it’s dry.

Otherwise, here are tips on how to store wood properly:

  • Make sure your piles of wood are not in a humid place;
  • Have boards and stickers  of the same  thickness and size on the same stack
  • Align stickers vertically and lay them flat
  • Allow enough space between stacks
  • Put wood piles onto flat foundations
  • Cover the wood with material that seals it from vapor;
  • Put weights on the woodpiles to prevent cupping

Don’t dry lumber too slowly

The traditional rule of thumb is to let the lumber air-dry for one year for each inch of thickness, but this is only a general rule and close monitoring of the lumber, especially with the help of a moisture meter, provides more flexibility.

How much does pressure-treated wood shrink?

A Treated board will shrink about 1/4” after installation. Thus, fasten the planks as tight as possible. For 1×6 pickets, these shrink a little less than 1/2″.

A standard piece of pressure-treated lumber, however, does not shrink the same amount along all of its dimensions. The greatest percentage of shrinkage occurs across the face of the grain.

Related reading: How to tell if wood is pressure treated

FAQs

Will pressure-treated wood warp as it dries?

It’s possible for pressure-treated lumber to warp as it dries, but this can be prevented by not over-drying the lumber, not letting moisture into partially dry lumber, and drying the lumber fast.

How to store pressure treated wood

  • Make sure your pile/piles of wood are not in a humid but a dry place;
  • Place boards and stickers  of the same  thickness and size on the same stack
  • Align stickers vertically and lay them on a flat wood surface
  • Allow enough space between stacks so the wood will have enough ventilation.
  • Put wood piles onto flat foundations
  • Cover the wood with material that seals it from vapor;
  • Put weights on the woodpiles to prevent cupping

Related: Do you need to seal pressure treated wood?

Can I leave Pressure-treated wood in the Rain?

No. It’s not advisable to leave wood that has been pressure treated under the rain. If you do, you need to re-dry the lumber before you paint it or start construction of your deck or framing project. But if you have used the pressure-treated lumber for deck boards or picnic tables, for example, it’s okay for it to get rained on.

How long should pressure treated wood dry before staining?

Two to three days are enough to wood stain pressure treated wood.

How long to let pressure treated wood dry before painting?

Sixty to one hundred twenty days of letting the air dry the lumber before applying paint to treated lumber. Check the wood periodically with the water test to make sure you don’t over-dry it. Then, you can start painting pressure treated wood. In case you’re too impatient, find out what happens if you paint pressure treated wood too soon.

Can pressure treated wood get wet?

Yes, it can get wet and exposed to the elements, but would not be harmed. Chemicals in the wood will fight moisture and insects. But this is not advisable on wood that has not been used. Note that wood expands when wet and contracts when it’s dry afterward. The movement results in warping, cracking, and splinting.  

Can you build a deck with wet wood

Yes, you can build decks with wet pressure-treated wood, albeit there will be disadvantages. The wet board is more slippery, making it difficult to cut for decking. The moisture will make your deck prone to shrinkage, cracks, and warping.

Rot will also be an issue on your deck because fungi develop where there is excess moisture on the board, even if you have done pressure treating the timber for your deck. 

Related reading:

Drying Pressure Treated Wood

The timetable for waiting for pressure-treated lumber varies from three days to six months. The same three days are needed for untreated wood to dry.

You, however, can speed up the drying out process by proper stacking and naturally letting the air dry them, or build your own kiln for kiln drying and produce kiln-dried wood at home.

Thus, when confronted with the question, “how long does pressure treated wood take to dry?”  you don’t need to worry as much.  

The several weeks of waiting for translate to easier handling, correct measurements, and zero warping and splinting. You get the desired results and because it’s treated wood your framing, deck or fence will be more durable and last longer than when you use untreated wood.

Check out the best below ground wood preservative to protect your pressure treated wood.

Leave a Comment