How To Waterproof Drywall Using Primer Paint and Membrane?
Whether it is a construction or renovation project, drywall emerges to be a vital component. While drywall is a durable material, prolonged water exposure can easily cripple its integrity.
Not to mention the mildew and mold growth which can ruin the whole aesthetic of your home. Water can damage drywall to an extent where you will need to repair or, in the worst-case scenario, replace both of which require significant investments.
Essentially, making your drywall waterproof at the installation time is the only thing that stands between you and the hefty repairing or replacing expenses.
So, how do you waterproof drywall? Fortunately, there is not one but two methods to do so, and this post is all about it. Here you can find the best methods and corresponding steps to waterproof drywall at home easily.
Can You Waterproof Regular Drywall?
Absolutely. There are several types of protective waterproof materials available that are designed to make regular drywall waterproof. Regular drywall is gypsum plaster sandwiched between two thick sheets of paper.
Unlike other variants of drywall, regular drywall does not have any remarkable capabilities, such as a soundproof or waterproof surface. Hence, it is recommended to apply some type of protective coating to enhance its durability.
You can consider installing pretreated drywall, but in some people’s experience, it may not be the best option every time. It is a common opinion that pretreating drywall is not as efficient as applying an outer protective coat on regular drywall.
However, the most essential factor that makes pretreated drywall the less popular choice is its high price.
By investing a few additional hours in manually waterproofing the drywall, you can possibly avoid more expenditure and use that money on other aspects of your dream home.
The only case when you cannot waterproof regular drywall is when it has active leaks and water damage. Water makes drywall soft and weak. Making such drywall waterproof may slow down further damage for some time, but it cannot reverse it.
Hence, the drywall will continue to degrade and will need to be replaced eventually. Thus, it is recommended to waterproof the drywall when new and undamaged.
How To Waterproof Drywall Using Waterproof Primer and Paint?
Waterproof primers are fundamentally created to enhance the durability of surfaces such as cement, masonry, drywall, etc. There are several types of primer, such as water-based, oil-based, and latex-based. Luckily for drywall, any kind of primer will give equally good results.
Primer creates a water barrier on drywall. Hence, this eliminates any contact with water and, along with it, the risk of water damage. Plus, primer is an adhesive. It makes the surface even and facilitates painting hence, providing a smoother finish.
Topping it with waterproof paint will further seal the drywall and prevent mold growth. Additionally, you will have the freedom to pick the color that matches the aesthetics of the rest of the house.
Required Items
For applying waterproof primer and paint, the following tools are needed:
- Waterproof primer
- Paintbrush, spray machine, or roller
- Microfiber cloth or drywall mop
- Waterproof paint
Step by Step Process
1. Cleaning the drywall
Often drywall can get dusty and dirty at the time of renovation or construction. Since dust can affect the primer’s performance, it becomes imperative to clean the drywall first.
Use a drywall mop to wipe the dust off from the surface. You can also utilize a microfiber cloth if a drywall mop is not available.
Do not use a wet cloth or mop to clean the drywall as you cannot apply primer on wet drywall, and it will only make the process more tedious and time-taking. Once the drywall is free from dust, dirt, and grime, it is ready for the next step.
2. Cover nearby area
Whether you are using a spray, roller, or brush, getting splashes of primer or paint on nearby objects is unavoidable.
It can be challenging to remove primer or paint from surfaces once it dries. Hence, before applying the primer, make sure all the nearby objects are covered.
3. Apply the primer
Start by applying a thin layer of high-grade waterproof primer, preferably using a roller. You can use a brush to apply primer on corners and other areas inaccessible by the roller. Using a spray for applying the primer will also work well.
As drywall is highly porous, it will not have any problem absorbing the primer regardless of the tool used for applying. However, you should be familiar with using these tools in order to get the best results.
Spray: Using spray makes the application process more convenient and less messy. If you are considering spraying the primer, you should pick a primer formulated for spraying, such as the Rust-Oleum Simply Home Interior Wall Primer.
If you have a primer that is not thin enough for spraying, you can add water, if it is a water-based primer or mineral spirits, if it is an oil-based one.
Always start by adding small amounts of water or spirits and stir the primer continuously. Note that not every primer can be diluted. Hence, read the manufacturer’s instructions before thinning the primer.
Check the consistency of primer by running it through a funnel. If it flows freely, pour it into the air spray container. Adjust the air pressure and other settings of the spraying machine as per your needs. Spray on cardboard or any other material to test the spray.
When spraying, keep the distance from the drywall and spray head angle the same at all times. Start moving the spray first, and then press the trigger to avoid applying excess primer at a place.
Brush: First, dampen the brush with water or mineral spirits based on the type of primer for smoother application. When applying primer using a brush, professionals usually use the cutting-in method. In this method, you start by applying the primer around the edges. A 2-inch nylon polyester brush is recommended for this step.
Next, apply the primer on areas that need special attention, such as patches in drywall. Then use a bigger brush for the primer to cover the entire drywall, starting from one side and brushing your way to the other.
Roller: You can easily buy a high-grade roller online if you do not already have one. Dampen it with water or mineral spirit based on your primer type. Pour the primer into a paint tray and dip the roller in the primer until completely covered.
Glide the roller to the ridged area of the tray a couple of times to remove excess primer. Start by the cutting-in method, as explained before.
Apply vertical strips in between to apply the primer in sections. Start from the top and paint your way to the bottom. Do not use vertical strokes but V or W-shaped strokes.
Applying more than one layer of primer maybe be needed. However, only proceed to apply the next layer when the first one is completely dry to touch.
Drying time is usually in the range of one to four hours. Still, the exact drying time varies with primer type, brand, and surroundings.
4. Let the primer cure
While primer only needs to dry for a few hours before applying another coat, it should be left for drying at least 24 to 72 hours before topping it off with paint.
5. Apply waterproof paint
Now that the primer is completely cured, you can apply waterproof paint of the color of your choice.
Make sure you wipe the drywall before applying paint to get rid of any dirt. Use a spray, brush, or roller to apply paint over the primer.
Usually, any surface which already has a primer coat will not need multiple coats of paint. Leave the paint for drying. After drying, the drywall is prepared for further work.
The layers of waterproof primer and paint together will be sufficient to waterproof the entire drywall. Drywalls made waterproof using this method can be installed in areas such as the basement, kitchen, and other places where water leakage and moisture are more common.
Precautions
- Do not use any cleaning agent or water to clean drywall.
- At the time of construction or renovation, there is already a lot of dust around. That, combined with fumes and the odor of primer or paint, can be very harmful. Hence, wear proper safety equipment while working.
- Check the drywall before applying the primer. If any part of the drywall is damaged, it should be fixed prior to using primer.
How To Waterproof Drywall Using Waterproofing Membrane?
Waterproofing membranes are specially created for waterproofing and can be made from silicone resins, acrylic copolymers, polyurethanes, or asphalt waterproofing agents.
These membranes isolate the drywall from external factors such as water, thereby making it waterproof.
The liquid waterproofing membrane is the most suitable kind for drywall as it is easy to apply. Once you apply a liquid waterproofing membrane for drywall, you will not need to worry about water damage for a very long time.
Required Items
If you want to use this method, you should have the following items:
- Primer
- Paintbrush, spray machine, or roller
- Microfiber cloth or drywall mop
- Sealant
- Fiberglass mesh tape
- Liquid waterproofing membrane
Step by Step Process
1. Clean the drywall
To apply a liquid waterproofing membrane on drywall, you need to apply at least one undercoat of primer.
Primer levels the surface and being an adhesive lets the waterproofing material bond well with the surface. As stated before, the drywall needs to be completely clean before application.
Using a drywall mop is an efficient and convenient method to clean the drywall. But in case one is not available, use a dry microfiber cloth to wipe the drywall.
2. Cover nearby objects
To avoid getting splashes of primer or the waterproofing membrane on unwanted areas or objects, cover the waterproofing area with newspaper or other material.
3. Apply the primer
You can apply primer using a brush, roller, or spray machine. The spray is the most convenient method, but you will need to ensure that the primer is spray-ready.
In case the primer is too thick to be sprayed, add a diluting agent such as water if it is a water-based primer or mineral spirit if it is oil or latex-based.
While spraying, the distance of the spray head from the drywall should be constant. Also, keep the spray head angle the same throughout the process.
In case you are using a brush or roller, use the cutting-in method to apply primer. The primer is applied on the four sides first using a 2-inch primer brush in the cutting-in method.
Next, apply the primer on areas that need special care, followed by covering the entire drywall. When using the roller, use V or W-shaped strokes.
Applying more than one coat of primer is not necessary for waterproofing membranes. However, if you feel that it is required, you can apply another coat of primer once the first one is completely dry.
4. Apply the sealant
Use a sealant to ensure water does not enter the drywall through the gaps between two drywall joints.
A silicone sealant is best for this purpose. Apply the sealant in the gaps between two drywalls. Gently press and glide your index finger over the sealant to get a smooth finish.
5. Appl the waterproofing membrane to the corners
While some primers dry within a few hours, it is always best to wait at least 24 hours before applying anything over the primer. This will allow the primer to stick well to the surface.
When it comes to picking an excellent liquid waterproofing material for drywall, there are not many options. The Redgard waterproofing material is our top recommendation.
Using a roller is the most suited method to apply waterproofing material. Pour the waterproofing material into the paint tray and load the roller. Apply a thin and even coat of Redgard to the corners of the drywall first.
6. Apply the fiberglass mesh tape
While the waterproofing material on the drywall’s corners is still wet, apply the fiberglass mesh tape over it. The mesh tape should be at least 6-inch wide.
7. Cover the entire drywall
Now apply the waterproofing material on the entire drywall, including the corners, over the mesh tape. Once the whole drywall is covered, let it dry.
Next, apply another coat of the Redgard waterproofing material. Generally, it will take 60 to 90 minutes to dry then it will be completely sealed and ready for further use.
Precautions
- While spraying primer, wear necessary protective gear such as face mask and goggles, etc.
Drywalls are a crucial component for interior wall construction, whether for residential or industrial buildings. You cannot afford to have water-damaged and mold-laden drywall. Even repairing or replacing these drywalls will lead to hefty expenses.
Thus, it is better to take the necessary steps to waterproof them at the time of installation. This will ensure that the drywall does not become weak and soft even after exposure to moisture.
