How Long Can Framing Be Exposed to the Weather?

Giovanni Valle is a licensed architect and LEED-accredited professional and is certified by the National Council of Architectural Registration Boards (NCARB). He is the author and managing editor of various digital publications, including BuilderSpace, Your Own Architect, and Interiors Place.

From supply challenges, lockdowns, or even budget cuts, there have been many reasons for construction projects to slow down or pause during recent years. If you’ve already constructed the wood frame of a building, it’s understandable that you’re worried about weather exposure.

Framing can generally be exposed to the weather for around three months with no issues, but the number drops if your area has extreme weather. The amount of framing damage sustained depends on exposure time, wood quality, whether the wood is treated or untreated, moisture, and temperature levels.

This article aims to explore the specific effects weather has on exposed framing. I’ll also cover how to prevent damage to your structure even with extreme weather.

The Dangers of Leaving Framing Exposed for Too Long

For the most part, you can expect minimal to no damage to your framing if you leave it for around three months. However, the exact answer depends on the weather conditions the structure is exposed to.

Below are a few of the unwanted effects of leaving framing exposed for too long:

Swelling. Wood framing can significantly swell and bend out of shape if it absorbs too much water from humidity, rain, or other sources. Warped and swollen frames can lead to uneven, or not level, construction.
Rotting. If moisture levels inside the wood framing reach more than 20%, there is a significant chance that it will begin to rot, though it takes time for decay to set in. Eventually, decay and rotting will negatively impact the structural integrity of the wooden frame.
Warping. This effect occurs when swollen wood dries out too fast or unevenly, reducing the structural integrity of the wood framing.

Note that while these effects may sound severe, it is not a quick process, and it takes a long time to cause significant damage to your framing.

Factors That Affect How Much Damage the Framing Will Sustain

The damage caused by exposing wooden framing to the elements is not instantaneous. Several factors come into play and determine how much damage the wood will sustain.

The Framing’s Total Exposure Time to the Elements

The most critical factor in determining the extent of damage caused by the elements is how long the framing is exposed. Generally speaking, the longer the wood is exposed to the weather, the more extensive damage it will sustain.

Also, longer exposure time means a higher probability of exposing the wood to extreme weather conditions. For example, leaving the construction site unattended for a week during summer won’t matter. However, if left for over six months, the seasons would change, and the rain and snow typical of autumn and winter are more extreme and will cause more damage.

The Quality of the Wood Used for the Framing

The timber used in construction is not just any wood you find in the forest, nor is it simply wood that has been cut up into planks. Wood from trees in the forest is processed until it becomes the timber you typically use in wood framing.

One of the main ways timber is processed is by drying it out, which allows it to handle more moisture. High-quality wood framing is more likely to withstand prolonged exposure to the weather and is less likely to sustain damage.

The Wood Used for the Framing Is Treated or Untreated

Many timber manufacturers treat the wood against microbial activity, making it harder to rot. As such, whether the wood is treated is a major determining factor in how long the wood framing will hold up against harsh weather conditions.

While not all wood is pressure-treated, many municipalities require that the wood used for the framing is treated, so check your local laws to be sure.

The Moisture and Temperature Levels in the Environment

The actual weather conditions that wood framing is exposed to will determine how much damage you can expect to find. For example, leaving the wood framing uncovered in stormy or rainy weather will likely do more harm than if the weather is bright and sunny.

Generally speaking, high moisture levels will contribute to more swelling and an increased likelihood of decay. If the weather clears up quickly after the rain, the wood will likely dry up just as fast, which leads to more significant warping as the swollen wood dries quickly.

How Other Weather Factors Affect Exposed Framing

As mentioned, rain and humidity in the air can cause swelling and decay, but other weather conditions may also affect exposed framing, including the following:

Heat and sunlight. High temperatures and intense sunlight can negatively affect the wood if exposed to it for too long, but it is less of a concern than moisture.
Wind. While strong winds can break the wood framing, moderate winds may reduce the damage caused by moisture due to evaporation.
Snow. Heavy snowfall introduces a lot of moisture to the wood, leading to swelling.

What To Do if Framing Has Already Been Exposed to the Weather

If the framing in your construction project has already been exposed to the weather for over three months, it’s best to hire a professional to inspect the wood’s integrity. The longer the wood is exposed to the elements, the more essential this inspection will be.

The inspector should be able to determine whether you can continue the construction project using the same framing or if it’s better to replace it. In some cases, if the absorbed moisture isn’t too much, there may be ways to air it out, including using carpet dryer fans or dehumidification equipment.

Conclusion

To wrap it up, you should not leave wooden framing exposed to the elements for prolonged periods, especially if you use low-quality timber in construction. Otherwise, there is a high risk of swelling, warping, and decay. All of these are bad for the structural integrity of your building.