What Makes a Climate Humid?
Have you ever been out with friends or family, and one or more of them comment on the humidity? Perhaps you yourself have made those same comments. Have you ever wondered what actually is making the environment of humid climates so unpleasant? It’s a simple answer, but there’s also a lot of science to it. The simple answer is that a humid climate has a lot of water vapor in the air. The more water vapor in the air, the more humid it will be. This water vapor appears in the atmosphere as water evaporates. Hotter climates tend to have more humidity because heat makes water evaporate faster. Places with a lot of trees will also have high humidity. This is caused by the amount of moisture trees release back into the air during a process called transpiration. This is water that was absorbed through the soil and is released through the leaves.
How to Pick the Best Materials
If you’re building any structure, you’re going to need to be able to choose materials that hold up in all climates. These structures are going to take a lot of abuse from wind, rain, animals, cold weather, and the heat. The materials you use have to be able to withstand all of it. This is especially true when it comes to choosing exterior siding. Moisture is the most destructive element that your siding will be exposed to. Wood or clay are materials that are ideal for warmer climates, which are more likely to be humid. In environments that have hot, humid days, but cool nights, it’s important to find materials that will be lightweight and have a low thermal mass. Thermal mass is the material’s ability to absorb and store heat. Concrete, bricks, and tile have a high thermal mass due to the large amount of heat energy needed to change their temperatures. This makes concrete an ideal building material for climates that are hot during the day but cooler at night. Using high thermal mass materials might help avoid some moisture problems in your building, but it will take a lot more energy to cool those materials down if you live in a humid climate. It’s best to use low thermal mass materials such as wood for your framework, walls, and ceilings.
8 Best Building Materials for Humid Climates
Since humidity is such a wide-spread issue that many places and climates have to deal with, there are many different materials that work. Below is a list of the 8 best building materials for a humid climate.
Wood is a common building material, but in general, it might not be the best option because of its ability to absorb moisture. However, engineered hardwood could work out much better if you live in a particularly humid climate. Engineered hardwood is made in high heat environments and uses pressure-treated plywood or fiberboard to bond to a thin layer of wood. This makes the material more durable and watertight, which would prevent warping and mold. That makes this ideal for flooring in humid climates. You can find these types of engineered hardwood flooring planks at places like Home Depot, where they have a variety of species and stains.
Natural plaster has the ability to absorb indoor humidity and release it slowly over time. Clay and lime plasters are mold resistant by nature, making them ideal for building in humid climates. What makes clay such a beneficial material for humid climates is that it’s capable of allowing moisture to pass through the building freely. Clay plaster is also capable of maintaining the indoor humidity levels by storing moisture when levels reach over 50%. The plaster will then release the moisture back into the air once it drops below 50% humidity. USG Structo-Lite Basecoat Plaster is an example of a clay plaster that works for humid climates. The only thing needed to mix this plaster is water, and it weighs less than some of the competitive options out there.
Concrete can be an effective building material in a humid climate if there is proper humidity control inside the structure. Excessive moisture will affect concrete negatively if there’s a lack of air circulation and climate control. When the heat gets into the building through vents, windows, and other openings, it will create condensation without proper circulation. Once this condensation occurs, it will settle on the concrete and potentially damage it. This is why it’s important to have proper ventilation and airflow throughout the building as well as sealing it so that it’s airtight. Home Depot has Eagle Concrete, which is a water sealant concrete that repels water. The water beads up on the concrete and is less likely to cause damage.
There are two types of spray foam insulation options to choose from open-cell and closed-cell. The one you use will depend on where in the building you decide to use the spray foam. Open-cell spray foam in humid climates should be used on attics, walls, and roofs. Open-cell foam is more breathable and allows moisture to pass through the building without causing damage to other areas. Closed-cell spray foam — or open-cell with a vapor resistant paint — can be used in basements and under floorboards where damage is more likely to occur from outdoor moisture. Closed-cell spray foam is also ideal for areas of your building that could be at risk of flooding. The Touch-N-Foam spray foam from Home Depot is moisture resistant and is closed-cell spray foam. It also doesn’t expand or shrink, which makes it a durable option to build with.
Ventilation is ideal to keep internal moisture at a comfortable level. This will ensure that the materials used inside — such as the joints and wall studs — won’t mold or rot from the moisture content. The best way to get natural ventilation is through wide windows that allow a cross-breeze to pass through the building. The best kind of window to use for humid climates is an energy efficient one that is properly sealed. If it isn’t sealed, moisture can seep in and cause harmful mold and other bacteria. A good example of an energy efficient window is the ThermaStar by Pella, which is available at Lowe’s. This window offers vinyl framing that has been made to withstand the weather.
When using windows won’t work to get the right airflow through the building, installing vents are another option too. Bathroom vents and vents above the stove can help decrease the moisture in the air left by showers or cooking. Another great way of keeping airflow moving throughout your building is the use of ceiling fans. These fans keep the heat down while also ensuring the moisture evaporates within your building more quickly. Ceiling fans like the Hugger 52in Indoor fan from Home Depot are great options and not too expensive. You’ll be able to keep the air cool and dry within the building, which will keep the humidity out.
This paint is an excellent building material for its ability to prevent mold and mildew. Almost all paint can provide a barrier that protects your building from the outside moisture. Rust-Oleum Zinsser exterior paint goes beyond what regular paint can. It has a strong mildewcide that keeps the mold from moisture from forming on the paint itself.
Moisture sealants are vital to making sure the building is protected against the moisture found in humid climates. Sealing wood is especially important due to its organic makeup. Moisture causes wood to rot, and the more moisture in the air, the faster that could potentially happen. Making sure that wood is sealed will help prolong its life. An example is Thompson’s WaterSeal, which can be purchased on Amazon. It only needs one coat and provides protection from water and moisture. Use it on decks, fences, and exterior wood.
Things to Consider When Building in Humid Climates
There are a lot of different ways you can do things, no matter what the project is. Here is a list of things you should keep in mind when building in a humid climate.
Watch Out for Vinyl Siding
Even though vinyl siding is great for its waterproof properties, it’s also prone to more cracking in the heat. If you live in an area that has a lot of rainfall as well as heat, your vinyl siding could suffer from it. The heat and rain could warp or disfigure thin layers of vinyl, so it’s important to keep that in mind when choosing what building materials you plan to use. Vinyl can be a viable option as long as you invest in higher quality material.
Keep in Mind Which Direction the Building Faces
One of the best ways to combat humidity is to reduce the heat inside. You can do this by paying close attention to the orientation of the building. Make sure there are rooms with two exterior walls. This will allow for better airflow through cross-breezes.
Other Insulation Options Available
Spray foam is a great option because of how sealed it gets where it’s applied. However, there are other options out there to consider as well. Some of them may even work out better for your building project. These are other great options because of the fact that mold doesn’t grow on them. Despite that, mold can grow on the paper backing found on most of them. It’s suggested that you don’t use any materials that get wet during installation.
In humid climates, having a vapor barrier could be more important than in non-humid climates. This barrier is usually made from plastic or foil, and it works to keep the moisture from the outside from getting into your home. These vapor barriers act as a shield to keep the humid air from getting through and settling on the cooler surfaces inside the wall. However, sometimes this can still cause more damage if not done properly. Despite the importance of vapor barriers, it’s more important to make sure a building is air sealed instead. Vapor barriers have the potential of trapping water vapor, which could cause more damage the longer it sits.
For your roofing options, you’re going to want to pick something waterproof and durable. It needs to be able to hold up against all weather and abuse. Here is a list of options that could work for your humid climate:
While mildew and mold are less likely to grow on asphalt shingles, there is still a chance that water can get beneath them and damage the structure underneath. A vapor barrier would be required to prevent this.
Cedar Shake Roofing
Cedar shake is a unique looking roofing option that you may be inclined to consider. If properly cleaned and maintained, it could last you 30 years. However, moisture can negatively affect a cedar shake roof. In order to prevent that, you need to keep the roof cleaned and maintained every 2-4 years.
The option of a metal roof can work in humid climates because of its nonporous makeup. There are options like powdered-coated metal roofing that would help prevent rust or corrosion. However, the biggest issue with metal roofing is the condensation on the underside of the metal panels. When temperature and humidity reach a certain point, the moisture in the air will condense on the underside of the panels. This could, in turn, cause damage to the inside of the building.
When properly installed and cared for, tile roofing options have the potential to last 100 years. The biggest problems with this style of roofing are how heavy they are, and their cost. They are typically more expensive than other roofing styles. The structure they are placed on must be able to hold the weight as well. One square foot of Spanish tile roofing weighs approximately 850lbs (386kg). Despite that, these do make an excellent roofing option.
Not only is slate waterproof, but it’s also fire resistant and one of the most durable roofing options available. The biggest problem is similar to the asphalt roofing option. Water and moisture have the potential of getting trapped underneath the shingles. This can cause damage to the roof material below. It’s important to place a waterproof material underneath the slate tiles before installing them. The only major concern with this style of roofing is that it’s expensive. You risk spending close to $900 per square foot of tile. Concrete tiles are a less expensive alternative. When it comes to your roof, you’ll need to make sure that it’s properly installed, sealed, and vented so that it provides you with the longest lasting life expectancy.
Drywall Is Moisture Sensitive
Drywall is a very moisture-sensitive substance. It’s known to fall apart easily with even a small amount of water exposure. This can be a problem since drywall is a common building material. Many homes use this kind of material for walls because it’s cheap. It’s important to take moisture level readings when installing drywall. If the moisture content in the drywall is over 1%, it’s considered too wet to use.
There are always going to be different materials you can use for building. Hopefully, this list of 8 best building materials for humid climates will help you find the right materials for your area.