Deck Popping In Cold Weather? (Here's Why!)

You move into a new house, you are sleeping peacefully in your bed, and then ‘CRACK!”. A loud sound like a gunshot pierces through your dreams, shooting you out of bed. No, there aren’t any prowlers on your property or fireworks going off. It’s just your deck, adjusting to the freezing cold temperature.

Hearing a loud popping noise coming from outside, especially during freezing temperatures, is no cause for concern. It’s not an indication that something is wrong with your deck or that some repairs are going to have to be made.

Your deck pops in cold weather due to the stress being released. The cold causes contractions which cause stress to build up in the wood. The release of this stress results in a loud popping or cracking sound. However, the sound is usually harmless unless the problem is from frost heaves.

If your decking boards do not have enough space around them to allow for the wood to expand and contract, this will cause noise. As they shrink and grow due to fluctuating temperatures, they will rub up against one another.

Much the same way that earthquakes happen as the tectonic plates deep under the earth shift and move. The stress throughout your deck builds up as they are forced against one another until something gives. This sudden movement, coupled with the friction, will cause a loud noise.

Most decks are built as a single unit, without the needed precautions in place to allow for expansion. They are semi-rigidly held in place and fastened along the edge of the wall. Any expansion and contraction that happens will cause stress in the deck as it has nowhere to move. Because these stresses can build with nowhere to go, when it finally happens the noise can be quite loud.

Moisture can get trapped between the deck boards, such as happens when it snows and then melts during the day. When night comes and the temperature drops to freezing, the moisture that slipped into the wood will expand as it freezes. This expansion will cause the wood to move and produce sounds. This could also loosen some of your deck boards which is why, come spring, you may have some repairs to do.

The boards will expand until they either pop a nail or break free of the frozen water that was binding them to another piece of the deck.

The boards and the joists (the boards under the deck that hold it up), will shrink at different rates. This depends on their materials, size, and protective layers. As they move, this will break the ice between them which may also cause the cracking sounds that are coming from your deck.

The joists are usually the first to freeze, as this is an area accessible to the cold air all around it. As the freezing conditions grow and cause the joists to expand, they will eventually break the ice bond. They can also push against the next board hard enough to break it free as well.

It usually takes 4 – 6 hours for this to happen, so most commonly these noises will occur in the middle of the night. By the time the sun starts to come up, everything starts to slowly thaw and resettle all the boards.

As the ground swells upwards due to the freezing conditions, this can cause the legs of your deck to move. This unequal movement will cause your deck to move, as stress is being applied unevenly. The boards will shift and twist to compensate for this movement, and the friction will make noise. If this is happening to you it may need fixing, as it will cause your deck to slope.

Although not usually an issue with professionally installed decks, as they take this into account, you can check for yourself. Using a level, see if the deck has maintained a flat, even surface. If so, the cracking has another source. You can also tell if this is an issue if you see nails that have surfaced from the top of boards.

Frost heaving can also damage stairs, causing them to tear or pull away from where they are secured to the deck. As the ground moves from frost heaves, anything that is secured into it will twist. If you notice that your deck is not level or your stairs are not as straight as they were, you will want to look into this issue.

One of the most destructive forces on a deck is Frost, which happens when sandy soil freezes. This freezing will cause the soil to expand and lift anything on the surface. These lifts can go up to, and past, 4”, which can cause some structural problems.

As one side lifts and the other doesn’t, this will cause instability in the decks supports and floor. Your deck may start to sag, lean, or become lopsided. The stair might twist and move and separate themselves from the deck.

The only way to prevent this is to make sure that the concrete footings of your deck are anchored in soil that won’t freeze. States that suffer from freezing cold winters will have building codes in place, directing you to the depth that your footings must extend to help deal with this problem.

Even with footings placed deeply, you can still have this be an issue for your deck. This can be mitigated by installing waxed cardboard tubes, or sonotubes, around the footings before installation. This will stop the soil from grabbing the cement and lifting it up, as the soil moves.

You can also add iron rebar to give the footings the strength they need to avoid damage like cracking, when the force of frost starts to form around them. When installing your footings, if you pour the cement in a bell shape at the bottom, this will also help to hold the structure in place over the winter.

Related Questions

Can You Seal a Deck in the Winter?

It is best if you do not seal a deck when it is below 50 degrees outside. If you try to seal your deck in the winter, the water may come out of the wood along with the sealant itself, as the temperatures drop to freezing. It usually takes a couple of weeks for a deck to dry out, which is why it is recommended to do this in the heat of the summer.

Is Cold Weather Bad for Wood Furniture?

No, neither hot nor cold temperatures really affect wood. What does affect it is humidity. As the temperature rises and lowers, the humidity in the air changes, and this fluctuation is what will alter the state of the wood. The difference in humidity will cause the wood to expand and contract. This can affect the paint, as well as the strength of the bonds holding the wood together. It can also affect the wood itself as moisture soaks into the wood and then shrinks and expands.

What Happens to Wood as it Freezes?

Wood stays the same size during all temperatures, it is the change in humidity which will affect the size and state of wood. When wood gets below freezing, the water inside will freeze, which can push apart the wood fibers. This can cause cracks in the wood and ruin its structural integrity.