How Do You Waterproof A Greenhouse? (Easy Way)

If you’re thinking about buying a greenhouse, there are several things to consider. For one thing, you want something that will last for many years without any problems.

 Also, where do you plan on putting it? If you live in a cold climate area (like myself), then an insulated and waterproof greenhouse is essential for keeping your plants warm during the winter months and preserving their moisture during dry weather. 

But how do you make sure your greenhouse is well-insulated? How do you know how much insulation is enough? And what’s the best way to waterproof the structure so that it doesn’t leak rainwater or condensation into your plants’ beds or soil?

Sealing your Greenhouse – Assembling the Legacy Greenhouse
– Waterproofing a greenhouse is essential for protecting plants and extending the lifespan of the structure.
– Properly sealing gaps and cracks is crucial to prevent water infiltration and maintain a controlled environment.
– Applying a waterproof coating or sealant to the greenhouse can enhance its resistance to moisture and weathering.
– Regularly inspecting and maintaining the greenhouse’s waterproofing measures is necessary to ensure their effectiveness.
– Consulting expert guides and resources can provide valuable insights and techniques for effectively waterproofing a greenhouse.

Paint It

Painting your greenhouse is one of the most effective ways to waterproof it. It can be done with a good primer and paint, but make sure you use a high-quality one that is waterproof.

For better results, use a brush rather than a roller when painting. Rollers tend to soak up more water than they should and will leave the walls looking uneven once dried. 

If you decide on using rollers, make sure that you apply multiple coats until the redness disappears completely and there’s no trace of green peaking through at all. 

This will help prevent mold growth later on down the road due to excess moisture trapped in between layers of paint

When it comes to reinforcing a canopy top, taking the right steps can extend its lifespan and ensure durability. Our helpful tips and techniques in this guide on how to reinforce a canopy top will help you protect your canopy and make it last longer.

Use Resins In The Wood

To waterproof your greenhouse, you can use resin. Resins are much like adhesives, but they form a hard, clear film that will protect the wood from water damage. 

If you want to ensure that your greenhouse is completely waterproofed, we recommend using epoxy resins.

Choose a clean and dry piece of wood for this project; make sure it’s free from any dirt or dust so the resin can adhere properly. 

Use a paintbrush or other small tool to apply the resin over all sides of each board in order to keep them sealed against moisture and mold growth. 

Allow the resin to dry for at least 24 hours before continuing with further construction tasks inside your new structure.

Use Weatherproof Glue

You can use weatherproof glue to seal the greenhouse. It’s a good way to waterproof a greenhouse.

To waterproof your greenhouse, you need to apply weatherproof glue along all of its seams and areas where two panes of glass meet.

Use Window Coverings

To keep your greenhouse warm and dry, use window coverings that allow for air circulation. They should also be easy to remove and replace, as well as easy to clean. 

Durable materials such as vinyl or aluminum will last longer than fabric ones and remember that it’s important for the material to be UV resistant so it doesn’t disintegrate over time.

To maintain the quality and longevity of your gazebo canopy, it’s essential to know how to treat it properly. Explore our expert tips and techniques in this informative article on treating a gazebo canopy to ensure its protection against various elements.

Use A Cool Roof

Cool roofs are roofs that reflect heat rather than absorb it. They reduce the temperature of the air around them by up to 20 degrees Fahrenheit and can decrease energy bills by up to 30% (Cool Roof Rating Council).

You can buy cool roofing materials, but you’ll save some money if you choose to simply paint an existing roof with a white or reflective paint that will protect your plants from overheating.

Use A Plastic Film Layer

A plastic film is a great option for waterproofing your greenhouse. It protects against ultraviolet rays and prevents water from seeping in, while also protecting plants from diseases and pests. 

However, the plastic film should not be considered a substitute for good ventilation. If you choose this type of system, place the plastic film on the roof and walls of your greenhouse to ensure that air flows freely through it.

Plastic Film TypeDescription
Polyethylene FilmCommonly used plastic film for greenhouse covering, known for its durability, flexibility, and cost-effectiveness.
Polyvinyl Chloride (PVC) FilmPVC film provides excellent light transmission, resistance to tearing, and UV protection, making it a popular choice for greenhouse applications.
Ethylene Vinyl Acetate (EVA) FilmEVA film offers high light transmittance, thermal insulation, and resistance to aging and weathering, ensuring optimal growing conditions.
Polyolefin FilmPolyolefin films are known for their superior strength, light diffusion properties, and resistance to chemicals and pests, ensuring long-lasting greenhouse coverings.
Ultraviolet (UV) Stabilized FilmUV-stabilized films are designed to withstand prolonged exposure to sunlight, providing protection against UV degradation and extending the lifespan of the covering.
Anti-Drip FilmAnti-drip films are specially formulated to minimize condensation and drips, preventing water droplets from falling onto plants and causing damage.

Place Self-Watering Trays In The Greenhouse

The importance of water conservation is often overlooked in the greenhouse industry, but it’s something to be considered especially if you are growing crops that require a lot of water. Self-watering trays can be used for many different plants and are great for conserving water.

To make these, you will need:

  • A piece of wood that’s about 24 inches long
  • A piece of wood that’s about 18 inches long (or whatever length will fit on top)

Hanging a canopy backdrop requires the right techniques and knowledge for a secure setup. Discover the best practices and step-by-step instructions in our comprehensive guide on how to hang a canopy backdrop and create an impressive and stable display for your events.

Get Polycarbonate Panels For The Roof And Walls Of Your Greenhouse.

Getting polycarbonate panels for the roof and walls of your greenhouse is a great way to waterproof it.

Polycarbonate panels are more durable and energy efficient than other options, but they’re also more expensive. If you can afford it, though, polycarbonate is the way to go.

Keep Your Greenhouse Well-Ventilated To Prevent Condensation

To prevent condensation from forming, you need to have good ventilation in your greenhouse. If it’s well-ventilated, the air can dry out and any water that does form will evaporate quickly.

If there is too much moisture in the air, it will condense on any cold surface like glass or plastic and form droplets of water that may eventually leak through cracks in your greenhouse frame or panes of glass.

To keep things dry inside your greenhouse:

Use fans to increase airflow throughout the structure. A fan placed at one end of your greenhouse will pull warm air out and draw cooler air into it from all sides so humidity doesn’t build up as easily. 

Place two fans at opposite ends if possible so they pull warm air out while drawing cool air into both ends of your structure at once. 

You can also use timers so they turn off automatically after a few hours each day when temperatures drop below 85 degrees Fahrenheit (29 degrees Celsius). 

You could also use solar-powered fans since they don’t require electricity which means there are no cords hanging around for you to trip over.

Ventilation MethodDescription
Ridge VentsInstall ridge vents along the peak of the greenhouse roof to allow hot air and moisture to escape, reducing condensation.
Louver WindowsIncorporate louver windows that can be opened and closed to regulate airflow, preventing stagnant air and excess moisture buildup.
Exhaust FansUse exhaust fans to actively draw out humid air from the greenhouse, promoting proper air circulation and minimizing condensation.
Automated Ventilation SystemsEmploy automated systems that monitor temperature and humidity levels to control ventilation and maintain optimal conditions.
Circulation FansInstall circulation fans to ensure even air movement throughout the greenhouse, helping to prevent stagnant areas and condensation.
Evaporative CoolersUtilize evaporative coolers to introduce a controlled amount of moisture into the air, reducing the likelihood of excessive condensation.

Make The Structure Sturdy And Durable

The structure of your greenhouse is the foundation of your waterproofing system. If a strong, sturdy frame isn’t built, then it won’t be able to withstand any water pressure that comes it’s way.

So how do you ensure that when a storm hits or it rains for hours on end, your greenhouse will be able to hold up? 

Your first step is to use wooden planks (not just any wood will do) and secure them with strong nails into the sides of the structure. 

Make sure that each plank is nailed down securely; this part is important because if one plank isn’t properly secured, then all other planks attached below that one won’t remain attached either and this could cause structural damage over time. 

You also need to make sure that whatever material you’re going with for roofing material (e.g., tar paper) lies flat against the surface of these planks so they don’t get punctured by water or wind gusts during storms/hurricanes etcetera!

When you need a temporary canopy, having the right guidance can make the construction process much easier. Follow our first-hand experience and detailed instructions in this guide on building a temporary canopy to create a versatile and portable shelter for your outdoor activities.

Seal Every Corner, Crack, And Crevice

Seal every corner, crack, and crevice with silicone sealant. This is an important step in waterproofing your greenhouse because it’s impossible to stop water from getting into your greenhouse without first sealing any gaps. 

Make sure that there are no gaps between the greenhouse and the ground; if there are, you could get water leaking through these areas in heavy rain.

Similarly, make sure there are no gaps between the greenhouse and walls or other structures built around it; this includes anything like backyards that aren’t covered by a roof (but don’t seal up any windows!). 

Finally, use a silicone spray on doors and windows to keep out rainwater as well as pests like mice these can be bad for food storage!

Waterproofing MethodDescription
CaulkingApplying a waterproof sealant to fill gaps and cracks, ensuring a tight and secure barrier against water intrusion.
WeatherstrippingInstalling weatherstrips around doors, windows, and openings to prevent water leakage and improve insulation.
Sealant TapesUsing specialized tapes with adhesive properties to seal seams and joints, providing a watertight seal.
Liquid Rubber CoatingsApplying liquid rubber coatings to create a seamless, flexible, and durable waterproof layer on various surfaces.
Waterproof MembranesInstalling waterproof membranes, such as EPDM or TPO, to cover large areas and create a long-lasting waterproof barrier.
Flashing SystemsUtilizing flashing systems made of materials like aluminum or PVC to protect vulnerable areas and redirect water away.

Maintain The Greenhouse Regularly

One of the most important things you can do to ensure that your greenhouse stays waterproof is to maintain it regularly. You should check for any cracks in the glass, which could let water in or allow moisture to escape, causing the greenhouse to overheat or cool down too quickly. 

You should also check for holes in the roof and walls, as well as small cracks around windows and doors.

In search of a replacement canopy for your gazebo? Save yourself the hassle and explore our recommended sources in this helpful article on where to buy a replacement canopy for a gazebo. Find reliable suppliers and ensure the perfect fit for your gazebo’s canopy replacement needs.


Remember to keep your greenhouse well-ventilated so that it doesn’t get humid and moldy. If you want to use a plastic film layer, make sure it’s not too thick and won’t restrict airflow through the greenhouse. 

Also, make sure that everything is sealed properly before installing any roofing materials or glues so they last longer than just one season.

Further Reading

How to Seal the Bottom of a Greenhouse in 3 Steps: Learn three simple steps to effectively seal the bottom of your greenhouse, ensuring a tight and secure enclosure.

How to Seal a Greenhouse: Discover essential tips and techniques for sealing your greenhouse to prevent air leaks, maintain optimal temperature, and protect your plants.

Best Greenhouse Covering Materials: Explore a comprehensive guide to the best materials for greenhouse coverings, including their features, benefits, and suitability for different climates and needs.

The “Further Reading” section provides additional resources related to the topic of greenhouse sealing and greenhouse covering materials. Each URL is accompanied by a shorter description that gives a glimpse of the content available on those pages.

Now, here’s the FAQs section based on the semantic of the title:


How important is greenhouse sealing?

Greenhouse sealing is crucial as it helps maintain the desired temperature, prevent air leaks, and protect plants from external elements. It creates a controlled environment that promotes optimal plant growth.

What are the common methods used to seal a greenhouse?

Common methods used to seal a greenhouse include caulking, weatherstripping, applying sealants, using insulation materials, and ensuring proper ventilation management.

How often should I check and reseal my greenhouse?

It is recommended to check and reseal your greenhouse annually or whenever you notice air leaks, gaps, or signs of deterioration. Regular maintenance and inspections will help ensure the effectiveness of the sealing.

What are the signs of a poorly sealed greenhouse?

Signs of a poorly sealed greenhouse include temperature fluctuations, excessive condensation, drafts or air leaks, pest infestations, and poor plant health. These issues indicate that the greenhouse may need resealing or repairs.

Are there specific sealants or materials recommended for greenhouse sealing?

Yes, there are specific sealants and materials designed for greenhouse sealing, such as silicone caulk, weatherstripping tapes, greenhouse sealants, and specialized greenhouse glazing materials. It’s important to choose materials suitable for the greenhouse structure and the intended purpose.