Could You Use Rough Cut Lumber To Build a House?

Giovanni Valle is a licensed architect and LEED-accredited professional and is certified by the National Council of Architectural Registration Boards (NCARB). He is the author and managing editor of various digital publications, including BuilderSpace, Your Own Architect, and Interiors Place.

One of the first decisions you need to make when building a house is the type of lumber. Modern lumber is heavily processed and treated in various ways. Additionally, the price of lumber is rising, so you may wonder if it’s possible to build a house using rough-cut lumber?

You can build a house using rough-cut lumber if it complies with the International Building Code and a certified inspector approves it. However, rough-cut lumber tends to absorb moisture and may be prone to infestation. Dry out the lumber one year for every inch of thickness to prevent warping.

Keep reading to learn more about using rough-cut lumber in construction. I’ll cover the benefits of its use and expand on how to do it legally.

The Advantages of Building With Rough Cut Lumber

The use of rough-cut lumber in home construction is becoming increasingly popular. Contrary to what you might have heard, the International Building Code (IBC) allows rough-cut lumber in some situations.

Here are a few of the advantages of building with rough-cut lumber:

Stronger wood: Because rough-cut lumber is not cut into standardized dimensions, there’s the possibility of cutting thicker planks that offer more structural stability. Also, rough-cut lumber tends to come from stronger wood species. Otherwise, it wouldn’t pass inspection.
Affordability: You can source your rough-cut lumber from anywhere, even that old tree blocking the view in your backyard. Even if you buy rough-cut lumber, it’s generally cheaper than stamped wood from the lumber yard.
Less waste: Most of the time, rough-cut wood is sourced from trees that would otherwise end up in a landfill. Also, stamped lumber is made in factories that waste a lot of stock to make the rough-cut lumber conform to standard quality ratings. For example, a 2×4″ (38×89 mm) rough-cut plank loses half an inch (1.27 cm) in height and width in the process.
Smoother final surface: There’s a high probability that you can achieve a smoother surface on the wood by planing it yourself because you’d have the time to pay attention to detail.

The Quirks of Building With Rough Cut Lumber

Rough-cut lumber is milled in a sawmill but has not gone through the treatment process and was not kiln-dried. It’s typically rough to touch and is usually further processed in the sawmill to make other (stamped) wood products, such as dimensional lumber and veneers.

Because it’s still the first stage in the production process, rough-cut lumber does not usually go through inspection, so it’s not stamped.

And since the International Building Code (IBC) requires that lumber used in construction should be graded and stamped by an authorized grader, rough-cut lumber is not typically used in building houses.

However, the IBC does allow rough-cut wood to be used in building the following, no questions asked:

Sheds, as long as they are not taller than 120 feet (37 meters).
Barns (for non-human residents, i.e., animals only).
Fences below 7 feet (2 meters).
Playground equipment.

How To Ensure Your Lumber Passes Inspection

Whether buying rough-cut lumber from a sawmill or providing them the timber to be processed, the only legal way to build using rough-cut lumber is to have it inspected. Not only will passing inspection ensure that your house is legally built, but it’ll also assure you that the construction is safe.

Here are a few tips to ensure your lumber passes inspection:

Educate Yourself on What’s Required

Before you even purchase your lumber, I highly suggest you read up on your local laws and regulations so that you’re not blindsided at any point. Also, brush up on the processing required for your lumber to pass inspection.

Talk To Your Inspector

It’s always best to have a good relationship with your inspector. You’ll find that they generally want to work with you to bring about the best outcome. They will likely guide you through what you should do to pass their inspection.

Hire the Inspector Early in the Process

It takes a long time to turn rough-cut lumber into anything usable, and it’s best to bring the inspector into the picture as early as possible. Discuss your plans with them and amend them if necessary.

Before hiring an inspector, make sure that they legally have the right to give you certification for your rough-cut lumber. As a precaution, ensure that their certification is valid in your area.

Treating Rough Cut Lumber for Homebuilding

To ensure that your lumber is suitable for construction, you must treat it. The following are the two methods you should apply.

Drying

One of the most critical steps in treating rough-cut lumber is drying it out. The lumber is still green and will warp if not dried adequately. Industrially, the lumber is often dried in a kiln. You can achieve the same results by airing it out. The rule of thumb is to dry it out one year for every inch (2.54 cm) of thickness.

Sanding and Applying Varnish

Before using any rough wood outdoors, applying a varnish to add water resistance is best. Sanding is enough for indoor use, but many woodworkers also stain and varnish the wood to prevent insect infestation.

You can sand the wood using a regular orbital sander. Ensure you are using even pressure and cover the entire surface for the best result. Start with low-grit sandpaper and work your way up for a smoother finish using the high-grit sandpaper.

You should apply an even coat of varnish and allow it to dry fully before you apply the second coat. Never apply varnish without sanding first. Varnish prevents moisture absorption but will need to be reapplied after some time, which varies greatly depending on the varnish you use. So, make sure to follow the instructions on the label.

Conclusion

Using rough-cut lumber to build your house is possible if you comply with local laws and regulations. It’s a versatile, affordable, and environmentally friendly option. You can also treat rough-cut lumber to prolong its durability and weather resistance.