Wow, what a winter!!! I don’t know about you, but my furnace was running non-stop. With the cold weather, it had to work overtime just to keep up. That was a common refrain throughout our region last winter with cold weather that was around for weeks and weeks.
During those chilly months, did you notice gaps in your wood trim? Open joints in your wood floors where everything was really tight the summer before? Did your crown molding have gaps at the ceiling and at joints between members? Believe it or not, a cold winter can really affect the appearance of the wood in your house.
Since wood was a living organism at one time, it was composed of lots of water. Most of the water is dried out of the wood before it is used in a house, but all wood has some degree of moisture left in it. When it is extremely cold outside for an extended period of time, furnaces have to run for a long time to maintain comfort in the house. This extended heating cycle dries out the air in the house dropping the relative humidity, which causes moisture in all wood products to dry, which leads to wood shrinkage. We have seen this affect hardwood floors, crown moldings, wood trim, floor joists and even furniture. Here are a couple examples of what we have seen.
This extended heating cycle dries out the air in the house dropping the relative humidity, which causes moisture in all wood products to dry, which leads to wood shrinkage.
One house with a newer addition had a large gap develop between the old hardwood floor and the new hardwood floor. We determined that the floor sheathing in the new addition had shrunk less than 0.1%, but this shrinkage that accumulated over the 48 ft long addition was enough to pull the new floor away from the existing and leave a 3/8” wide gap. This gap shrunk as the humidity level rose in the house during the summer, so repairs to the gap were postponed until the end of the summer to allow for the expansion.
Another recently remodeled house had crown molding installed throughout the main floor. The molding had pulled away from the ceilings almost universally throughout the house. This was a case where the wood molding had shrunk due to the low relative humidity in the house causing it to pull away from the ceiling.
If during cold weather you see gaps showing up in the wood items in your house, but everything else seems to be fine, it is likely that the long heating season is causing your wood to shrink and that no other structural issues are involved. Hopefully the higher humidity that comes with the spring rains and summer will help everyone’s wood swell up again and those cracks will shrink.
Want more residential tips? Read Good Crack or Bad Crack? Residential Cracks and What They Mean.