Common Problems With Masonite Siding

Masonite siding, also known as hardboard siding, is a budget-friendly siding choice that was popularized in the 1980s and early 1990s. It’s made of wood fibers that are held together with glue or resin through a heat and compression process. It was originally developed as an alternative to real wood, vinyl, and aluminum sidings. It was originally believed to be lower maintenance than wood, but with better looks than either vinyl or aluminum. It was intended to fill a gap for homeowners that dislike the look of vinyl but wanted something lower maintenance than wood.

However, masonite had many problems of its own. Just 20 years after its creation, the original manufacturers were hit with multiple lawsuits because the material preformed so poorly. It’s currently still available as “hardboard” although most people still refer to it as masonite. Regardless of what it’s called, the material has many common problems that often lead to its replacement.


Swelling, buckling, and rotting are all really common issues with masonite siding. This is caused when moisture begins to infiltrate the siding. The wood chips and resin are not stable when they become wet. Instead, the wood swells, causing the boards to warp and buckle. Over time, the wood then begins to rot, and the boards will begin to soften and decay. There is nothing that can fix this once it begins, so the only solution is to replace the siding.


Blistering is another common issue with masonite. While the material is supposed to be lower maintenance than wood, the paint is not a permanent finish. It can blister and bubble off of the siding when exposed to heat or moisture. When this happens, not only does the siding look unsightly, it also becomes more susceptible to moisture problems beneath the paint.

Mold and Mildew

When the masonite takes on water, it doesn’t easily let it go. The boards tend to stay damp, which makes them the perfect medium for growing mold and mildew. At the least, this can lead to stains on the exterior of your home. At the worst, the mold can also begin to grow inside your walls, infiltrating the interior of your home as well.

Insect Issues

While masonite isn’t a solid wood product, it is still made of wood. And therefore, it’s also susceptible to insect activity. As the wood begins to soften, it can become very attractive to some types of insects including termites and carpenter ants. These insects will further decay and compromise the integrity of the boards, which will further the need for replacement.


Even if you try to stay on top of your masonite, scraping any blistered or cracked areas and applying new paint, you may not be able to stop or prevent discoloration from occurring. Discoloration comes from the masonite itself. It may be caused by the resin or by mold and mildew. The stains will seep out onto the paint, even if the paint is new.

Bowed Wall Studs

When you have siding that’s hanging onto a lot of moisture, you don’t just need to worry about the siding itself become bowed and warped, you also need to worry about the wall studs. Your wall studs are made of wood, and they will absorb moisture over time. This is part of what normal siding is supposed to prevent; it’s supposed to stop the moisture from infiltrating the studs of your home.

However, masonite absorbs a lot of water and can transfer it to your wall studs over time. This can be a particularly bad problem if house wraps with moisture or vapor barriers were not used to help protect the studs. Bowing studs can cause significant problems throughout your home, and may result in major renovations and repairs when the time comes to replace the siding.

What Options Do I Have?

There are plenty of wonderful siding choices today that will not only last much longer and with less issues than masonite, but also improve your homes energy efficiency along the way. Schedule a free in-home estimate with one of our exterior remodeling design consultants and learn more about some of the options we can provide for your home.

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