How to Weatherproof Your Plastic Shed

Plastic garden sheds are well-favoured for their durability, affordability, and low maintenance requirements. Even better, they can withstand a range of weather conditions, from rain and wind to extreme ones.

However, even the most robust ones need extra protection against these elements. This post will explain why weatherproofing your plastic storage is essential. Practical tips to prolong its life and ensure it continues to serve its purpose for many years await!

Assessing Your Shed’s Condition

BillyOh Duraplus 8ftx8ft Plastic Apex Shed
BillyOh Duraplus 8ftx8ft Plastic Apex Shed

This step is crucial before weatherproofing as it allows you to identify any issues or wear and tear. Failure to do so may affect the effectiveness of the process. It may also lead to suboptimal results, causing further damage to your plastic shed.

To inspect:

  • Check for cracks or holes. Such damages may seem small at first, but they can allow water and other elements to penetrate the shed. Also, keep in mind that they can become larger over time and cause more significant damage.
  • Look for fading or discolouration. Overexposure to sunlight can cause plastic sheds to fade or discolour. This can be a sign of weakness and make the shed more susceptible to other types of impairments.
  • Inspect the roof. The shed’s roof is particularly vulnerable to weather damage. Check for any holes, cracks, or missing tiles that can cause water damage to the interior.
  • Examine the foundation. Ensure it’s levelled and secure. If the shed base kit is not, the garden building can shift or move, causing structural damage.
  • Watch for mould and mildew. Mould or mildew growth is fond in areas with poor ventilation or high moisture levels. Not only can overlooking them cause severe damage to the shed, but they also pose a health risk.

Identify any issues that need to be addressed before applying waterproofing materials. This ensures your shed is well protected from the elements, and you can extend its lifespan.

Choosing the Right Materials

BillyOh Ashford Apex Plastic Garden Storage Shed Including Foundation Kit Grey
BillyOh Ashford Apex Plastic Garden Storage Shed Including Foundation Kit Grey

Some weatherproofing materials are not suitable for garden sheds plastic. But the following options are appropriate:


A sealant is applied to the surface of the shed to create a protective barrier against moisture. It’s easy to apply and affordable, making it a popular choice for DIYers.


Yes, you can paint plastic storage sheds! In fact, doing so can provide an extra layer of protection, as well as enhance its appearance. But it’s important to use the right type of paint and techniques to ensure the paint adheres properly.

Use a paint that is designed for plastic surfaces, such as acrylic or latex-based paint. These paints adhere well to plastic and provide excellent protection against the elements. Before painting, ensure that the garden building is clean and dry.

Spray-on coatings

Sure, painting your heavy duty plastic shed is possible. However, it may not be necessary if your primary goal is weatherproofing. This is where spray-on coatings come into play.

Spray-on coatings provide a long-lasting protective layer against water and UV rays. Although more costly than other materials, they offer excellent protection and durability.


Tarpaulins are heavy-duty sheets that can be used to cover sheds. They are a cost-effective way of providing temporary protection, particularly during winter.

To use, measure the dimensions of your shed and get one that’s slightly larger than the unit itself. This will allow you to cover the entire structure and ensure it’s protected from the elements. Drape it over the roof and sides, making sure it’s taut and secure.

Applying Weatherproofing Materials

BillyOh Oxford Pent Plastic Shed Dark Grey With Floor
BillyOh Oxford Pent Plastic Shed Dark Grey With Floor
  1. Clean the surface. Make sure the surface of your plastic potting shed is clean and dry. Remove any dirt, debris, or grime with soap and water, and let it dry completely.
  2. Choose the appropriate weatherproofing material. Depending on your area’s weather conditions, you may use a sealant, spray-on coating or paint.
  3. Apply using a brush or roller, and cover all areas, including corners and edges. Allow the material to dry completely before applying a second coat if needed.
  4. Take safety precautions. Wear gloves and safety goggles to avoid contact with the material and protect your eyes. As much as possible, work in a well-ventilated area to avoid inhaling fumes from the product.
  5. Allow the material to dry. Let it dry completely according to the manufacturer’s instructions. This may take several hours or even days, depending on the product and weather conditions.
  6. Repeat the process as needed. Depending on the weather conditions in your area, you may need to reapply every few years. This will help maintain its protection.

Note: Different weatherproofing materials may have different application instructions. So always read and follow the product label carefully. Additionally, some products may be flammable or emit harmful fumes. Thus, it helps to take all necessary safety precautions and work in a well-ventilated area.

Extra Tips

To prevent drafts and keep your plastic storage shed insulated, use weatherstripping. Apply the strips around doors and windows, and this will help keep out cold air and moisture.

Keep the area around your structure clear to prevent damage from falling branches or debris. Trim back any overhanging trees or branches, and remove any debris lying around.

Inspect your garden building regularly for any signs of wear and tear. Check for cracks or damage and repair any issues promptly to prevent further damage.

By taking these steps, your shed can stay weatherproof and functional for many years.


Weatherproofing a plastic shed is a crucial step in protecting it from the elements. By following the steps, you can prolong its life and keep your belongings safe and dry. Plus, ensure it remains an attractive and functional addition to your outdoor space.

With a little effort and investment, you can keep your plastic shed safe from the weather for years. So don’t wait; take action now and weatherproof yours!

Browse through Garden Buildings Direct’s incredible collection. Check out our top picks, including the vertical storage cabinet and the 6×3 plastic shed.

Now, let’s dive into the next topic: Do Plastic Sheds Need a Base?