Sealing board and batten siding is as critical to the success of the project as the material itself. True board and batten siding is traditionally done with real wood boards and battens, which will decay over time unless the wood is properly sealed against moisture. Today we will briefly discuss why board and batten siding must be sealed, what materials to use, and offer advice from the pros to make the job the best it can be.


Do I Need to Seal Board and Batten Siding?

Board and batten siding must be sealed against moisture or it will likely warp, crack, and split. If you have ever noticed how an old barn looks ragged, unsealed board and batten siding is usually the culprit. As construction designs evolve, board and batten siding remains popular for everything from starter homes to luxury mansions due to its clean aesthetic and effectiveness in shedding water.

If real wood is used, the pores in the wood grain must be sealed or the boards and battens will act as a sponge and absorb moisture from the air. In dry, arid climates the problem is less severe, but in temperate climates with distinct seasonal rains and snow, moisture can be a problem. In these regions, board and batten siding must be sealed with a wood sealer or painted with exterior grade paint to block the absorption or rot will likely follow.

What Will Happen If I Don’t Seal Board and Batten Siding?

If board and batten siding remains unsealed it will absorb whatever moisture is present, leading to warping, twisting, splitting, and rotting. As a siding material, board and battens must be tight to each other, or rain and snow can penetrate the siding and wet the wall framing. Some of the damage can be mitigated with the use of house wrap, but only if it is sealed properly.

How Do I Seal Board and Batten Siding?

Step 1 Clean the Surface

The first step to seal board and batten siding is often a pressure wash. Especially if the siding is weathered, pressure washing will remove any dirt, grime, or loose grain that could prevent good adhesion to the wood. If pressure washing is done, it is best to do it in the summertime when then ambient temperatures will ensure complete drying. Never attempt to seal wet board and batten siding, as the sealers are often water-soluble and will be diluted. 

Step 2 Select a Sealer Designed For the Project

Perhaps the most important step in sealing board and batten siding is to choose the correct product. Exterior grade paint does a great job of sealing board and batten siding, but many homeowners prefer the look of natural wood. In these instances, choose a proper sealer and application method for the project.

For example, if the project is large (like a whole house) consider spraying the sealer or enlisting help. Sealers (as well as paint) are applied in layers, so you may find yourself repeating the job a few times. Spraying the sealer takes most of the physical effort out of the project, so consider making the investment in a sprayer if it makes sense.

To spray a sealer, it must usually be thinned first or it will clog up the spray tip, so be sure to purchase a sealer that can be thinned. Some sealers are designed to be brushed or rolled on, and are usually applied right out of the can. Roll-on or brush-on sealers are generally applied in two or three coats, with adequate drying time allowed between coats.

Step 3 Spray, Roll, or Brush?

In this section, we will describe the pros and cons of each sealer application method. Generally, the more physical effort required, the less the project will cost. 

  • Brushing the Sealer

Using a paintbrush to apply the sealer has its advantages. Brushed-on sealer can be controlled more easily and drips can be avoided as the sealer is applied, because the sealer can be spread evenly before it dries. Brushing on the sealer is also very cost-effective and requires little skill. However, brushed-on sealer is quite slow and tedious to apply, so if the project requires speed using a brush is not recommended.

  • Rolling the Sealer

The next option is to use a nap roller. Nap rollers are often seen on the end of an extension pole and rolled vertically onto a surface. Generally, you’ll want to select a roller that matches the texture surface. For example, if you are sealing smooth board and batten siding, like that often found on a home, you’ll want a short nap roller. Rougher, more coarse lumber like that often found on a barn will require a long nap roller to reach the uneven surface and seal the grain.

  • Spraying the Sealer Consumer Model Sprayer

Spraying the sealer will yield the best results with the least amount of effort, but will obviously require a sprayer. Commercial sprayers can cost upwards of $300.00 for even a basic model, but homeowner models are available, like this one. Sprayers designed for homeowner use are usually electric and will not require an air compressor or tank. Units like these have a reservoir cup instead of a tank, so refilling is more frequent, but they do a great job of applying the sealer quickly and evenly.

Another method of spraying sealer is often even less expensive if you own an air compressor. Spraying sealer is perfectly possible with a high volume, low-pressure spray gun like this one. HVLP sprayers, as they are known, rely on a separate air compressor and gravity to apply the sealer. Again the reservoir is usually small, so you will spend time refilling it more often.

  • Spraying the Sealer Professional Model Sprayer

If you’re planning to do the project often or the project is large, a commercial sprayer may be a good investment. Professional sprayers, like this one, do not require a separate air compressor and spray the sealer directly from a bucket of thinned sealer. Known as on demand sprayers, these devices have an internal air compressor that only operates whent the trigger is activated. Obviously, this method is very fast and effective, but it will require more maintenance and cleaning.

However, spraying sealer will usually require a process called backrolling. Backrolling is typically done with an 18” wide roller to disburse any puddling of the sealer and spread it evenly across the surface. The best results often come from a two-person team, in which one person sprays and the other backrolls. Working in tandem also prevents runs and drips by spreading the sealer before they can form. 

Seal Board and Batten Siding and It Will Last Forever

Board and batten siding is simple, economical, and effective, which is why it is still in use today. Board and batten siding is used for visual appeal and cost-effective protection, but it does require regular maintenance. If you want board and batten siding on your home, just remember to inspect it regularly, keep it sealed, and it will last as long as the home.

Editorial Contributors
Matt Greenfield

Matt Greenfield

Matt Greenfield is an experienced writer specializing in home improvement topics. He has a passion for educating and empowering homeowners to make informed decisions about their properties. Matt's writing focuses on a range of topics, including windows, flooring, HVAC, and construction materials. With a background in construction and home renovation, Matt is well-versed in the latest trends and techniques in the industry. His articles offer practical advice and expert insights that help readers tackle their home improvement projects with confidence. Whether you're a DIY enthusiast or a seasoned professional, Matt's writing is sure to provide valuable guidance and inspiration.

Learn More