Is Our Freeze/Thaw Winter Damaging Your Home's Siding?

This winter, many U.S. and Canadian cities have experienced record low temperatures followed by unexpected warm-ups. This cycle of freezing and thawing puts great stress on roadway surfaces, underground pipes and exterior siding. It's what causes water main breaks and highway potholes – and it can cause significant damage to a home's siding. The freeze/thaw cycle occurs because water expands by nearly 10 % as it freezes. If water gets trapped in a siding material like fiber cement and the temperature falls below 32° F, it creates extreme pressure on the siding material as the water freezes and expands.

Some cities have just a few days of freeze/thaw cycles per year. Other places aren't so lucky: The Denver area has more than 105 days of freeze/thaw annually, while cities in northern Michigan often get 102. Baltimore logs about 83 days and Kansas City has 79 days each year. When the freeze/thaw cycle happens repeatedly, year after year, the cumulative effect can cause cracking and serious structural damage to fiber cement and vinyl siding.

Here's how today's most popular siding choices compare when it comes to combating freeze/thaw damage:

Fiber cement – Since fiber cement is essentially concrete, it's naturally more brittle than engineered wood siding and other material. That makes it more susceptible to cracking or breaking when water penetrates the substrate and expands as temperatures fall. There's a lot of talk these days about “smart concrete” that can resist freeze/thaw damage, but that technology is still in the testing stage.

Vinyl siding – Vinyl contracts and expands significantly as the temperature changes. That's why it must be loosely installed on a house to allow for movement. Like fiber cement, vinyl siding is more likely to crack in the winter.

Traditional wood siding – It requires a high level of maintenance to protect traditional wood siding from freeze/thaw damage. Without routine maintenance like painting and scraping, wood will easily warp, crack and split.

Engineered wood siding – This material is specially designed to resist cracking and splitting. Because products like LP^® SmartSide^® Trim & Siding are made from a combination of treated wood fiber and industrial-grade binders and resins, they're better able to withstand damage from freeze/thaw cycles.

Freeze/thaw cycles will continue to produce potholes on our roads, but engineering breakthroughs can prevent them from damaging home siding.