According to PWC, the global construction industry is expected to be worth $15.5 trillion by 2030. As the economy continues to improve and more construction projects begin, contractors are working hard to keep up with demand. This often entails working in extreme temperature ranges, which impact the materials used.
In a previous blog, we discussed considerations to make when applying sealants in cold temperatures.
Similarly, certain considerations should be taken into account when installing high performance sealants in hot temperatures. Let’s take a look at how the summer months can impact sealants and what to consider for proper installation:
Reaction with Moisture
Most one-component, high performance sealants rely on a reaction with moisture to cure. The moisture can be from various sources including:
- Relative humidity
- Precipitation/Voluntary moisture from a hose
- Moisture from the substrates
Relative humidity is typically the preferred source of moisture.
- Precipitation and voluntary moisture can often introduce too much moisture too soon. This can potentially compromise the cured sealant’s performance and cause surface blistering with some technologies.
- Relying on the substrate’s moisture can also impede the sealant’s ability to reach full bonding or adhesion capability.
However, while the relative humidity is preferred, it’s important to note that the moisture in the air is often higher in summer months. A 60% relative humidity in 50°F is not the same amount of moisture at 90°F.
This means that in warmer temperatures, high performance, moisture reactive sealants will skin and cure quicker. As a result, they will need to be installed and tooled promptly.
It’s also important to consider the type of substrates that the sealants are being installed upon. In summer temperatures, building materials experience a high degree of expansion. This means that joints can be narrower than they are at a median temperature of 70°F.
The level of expansion also varies depending upon the type of material. For example, the movement due to thermal changes of concrete vs. aluminum differ significantly in higher temperatures.
From a specification perspective, it’s important to install high performance sealants as close to a median temperature of 70°F as possible. Doing so ensures that the joints have average joint width. Tips on how to do this include:
- Install during a cooler time of day.
- Use the side of the building that doesn’t get the direct summer sun.
Smart, Summer-Proof Products
Bostik’s Pro-MS 50 Textured is one sealant in particular that is tolerant to moisture extremes. As it cures, the by-product can pass through the product. Therefore, it is not susceptible to blistering or superficial surface bubbling.
For more information on Bostik’s sealants call 800-7-BOSTIK.
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