You’ve probably noticed that most dimensional lumbers are available in regular and pressure-treated varieties. It’s not hard to wonder if you can use pressure-treated wood for framing because it’s more rot-and insect-resistant. We’ve done our homework and fully answered that question here.
You can use pressure-treated wood for framing, but it is much more expensive and contains potentially toxic chemicals. So only use pressure-treated lumber outdoors or where framing touches the foundation. Pressure treatment is unnecessary in most other applications because house framing rarely gets wet.
Keep on reading for a detailed run-down of the above answer. We’ll also consider the pros and cons of using pressure-treated wood indoors. Lastly, we’ll answer some other related questions.
Which Applications Are the Most Appropriate For Pressure-Treated Wood?
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Numerous framing applications require pressure-treated wood. More precisely, most building codes demand pressure-treated wood for all framing that comes into contact with the foundation.
This is because the wood may absorb moisture from the concrete and rot. By substituting pressure-treated wood for untreated wood, the home’s durability and stability are maintained.
Similarly, any framing that may come into contact with water would benefit from pressure-treated wood. This category includes outdoor awnings, decks, sheds, and barns, among other things. While pressure-treated wood is costly, it lasts significantly longer when exposed to moisture.
Take note that building codes vary by city. As a result, the requirements and possible applications for pressure-treated wood vary.
Consult a local building enforcement officer, contractor, or architect to guarantee you are adhering to local codes. Outdoor decks are among the most popular uses for pressure-treated wood.
What Characterizes Pressure-Treated Wood?
Pressure treatment utilizes standard lumber and applies pressure to the wood to force chemicals into it. This process alters the chemical composition of the wood, imparting it with a dark brownish/greenish hue.
In the 1940s, pressure-treated wood contained chemicals that were harmful to humans. Nevertheless, modern pressure-treated wood is far less dangerous due to the use of borates and other gentler chemicals.
Pressure-treated wood is resistant to insects and rots due to the chemicals used. In addition, the chemicals make it difficult for fungi and bacteria to chip away at the wood, rendering it unappealing to insects.
These pathogenic microorganisms are found in virtually all moist, dirty environments. This means that pressure treatment is an excellent way to extend the life of wood that has been exposed to moisture.
Is Pressure-Treated Wood Suitable for Interior Framing?
As per common perception, modern pressure-treated wood can be used indoors. Even so, it is strongly recommended that all sawdust and debris be removed before the home can be inhabited. In addition, when working with pressure-treated wood, it helps if you wear a respirator to avoid inhaling hazardous sawdust.
Working with pressure-treated wood is identical to working with untreated lumber. Since pressure-treated wood is heavier, expect to do more work when framing a home with it. However, the strength, as well as the support abilities of pressure-treated and untreated wood, is identical.
There is debate over the safety of pressure-treated wood for indoor use. Some carpenters and designers have expressed concerns that pressure-treated wood will leach toxic substances into the home.
However, the Environmental Protection Agency (EPA) reports that the toxicity of pressure-treated wood varies significantly depending on the type. Bear in mind that no source recommends using pressure-treated wood for chopping boards or countertops.
Ultimately, the interior framing should never be exposed to moisture, and siding, sheeting, and roofing all work to prevent this. As a result, the rot-resistance property of pressure-treated wood is irrelevant indoors.
Pressure-treated wood can be used indoors. But, the minor additional benefits and possible risks are generally insufficient to justify the significant cost increase.
Can Pressure-Treated Wood Be Used for Floor Joists?
As with other interior framings, floor joists are possible for pressure-treated wood. In addition, pressure-treated wood floor joists have a theoretically longer life expectancy. Nevertheless, pressure treatment of the majority of floor joists is ineffective because they don’t become wet.
The situation is slightly different for floor joists adjacent to a crawl space on the ground floor. This area requires the most pressure-treated wood of all the interior framing spaces.
Crawl spaces are typically open to the ground and can become extremely wet during certain seasons. Thus, all that keeps your framing from the wet moist soil is the room of air in your crawl space.
Untreated wood can last hundreds of years as floor joists above a crawl regardless of the preceding. It’s because water requires a direct path to the wood. In general, increased local humidity alone is insufficient to cause noticeable rot of floor joists in a crawl area.
Can Drywall Be Attached To Pressure-Treated Wood?
Yes, drywall can be attached to pressure-treated wood in the same way it’s connected to untreated lumber. Attach the drywall to the framing with drywall screws every 12 to 16 inches. As with other applications, exercise caution as drywall can be quite heavy.
Why Isn’t Pressure-Treated Wood Acceptable for Interior Use?
As mentioned previously, you can use pressure-treated wood indoors. Nevertheless, regulatory agencies advise against using pressure-treated wood in certain situations, such as chopping boards and countertops.
People typically avoid using pressure-treated wood indoors out of concern for the chemicals leaching into the surroundings, causing health issues. Another issue that is occasionally raised is that pressure-treated wood is more combustible than untreated lumber.
However, there is no proof that pressure-treated wood ignites more quickly than untreated wood. With that said, if pressure-treated wood does catch fire, inhaling the smoke is extremely dangerous.
Is Treated Lumber Required to be Sealed?
Yes, you must seal treated wood, and this is because excessive moisture shortens its lifespan despite its resistance to insects and rot. As a result, if left bare in outdoor spaces, it is prone to splitting, warping, and mildew growth.
Sealing pressure-treated lumber protects it from moisture. Thus, consider this practice for outdoor applications irrespective of whether you use treated or untreated wood.
Additionally, allow the wood to dry before applying the sealer. Chemicals in the lumber may leave behind moisture. Thus, a few days should suffice to dry it depending on the climate.
What Is the Best Way to Seal Pressure Treated Wood That Has Been Cut?
Cut-N-Seal can be used to seal pressure-treated wood that has been cut. It is a water-based brush-on formula with a water repellent that protects treated lumber from cuts and holes. Additionally, Cut-N-Seal is user-friendly due to its low odor, and it cleans up easily with soap and water.
Woodcare Clear Wood Preservative protects wood from borers and decay. Moreover, you can use it to seal treated pine, and softwood timbers’ cut ends.
The product, however, is only suitable for use above ground. As such, make sure that you adhere to all applicable precautionary measures.
Conclusion
There are numerous advantages to using pressure-treated lumber. Some include preventing premature wood damage and decay. The wood will also retain its insect resistance and have a longer life.
The question of whether pressure-treated wood can be used for framing has been addressed. We’ve also discussed the advantages and disadvantages of pressure-treated wood in both outdoor and indoor applications.
Bear in mind all precautions and take them seriously to avoid future health problems.
