How To Waterproof a Shed Using Flex Seal Products

Because It Works

Sheds provide us with extra space to store tools, garden gear, and more. However, without proper waterproofing, even the sturdiest shed can be at risk. Water damage isn’t just inconvenient; it can be costly and even compromise the structure itself. Fortunately, you can waterproof your shed with the help of the Flex Seal Family of Products. These step-by-step instructions will help keep your shed dry, safe, and looking great.

Note: These instructions are designed for wood-frame, steel-skinned sheds.

Materials Needed

Flex Seal Spray
Flex Seal Liquid
Flex Caulk
A high-quality paintbrush or roller
A stirring stick
Drop cloths to protect the surrounding area
A stiff brush or broom
Soap and water
Sandpaper or a scraping tool
Caulking finishing tool
Protective gloves
Drop cloths or masking tape for areas you want to protect

Steps

Note: Before using Flex Seal products, read all directions carefully and take proper safety precautions, such as being in a well-ventilated area and wearing protective gear while applying.

1. Inspect and Prepare the Shed Surface

For best results, it’s crucial to start with a clean, well-prepared surface. Before applying Flex Seal products, inspect your shed thoroughly. Pay close attention to areas around windows, doors, and the roof where cracks or gaps might allow water to enter.

Next, use a stiff brush or broom to sweep away any dirt, dust, or debris from the surfaces you’ll be treating. If necessary, wash the areas with mild soap and water. Make sure all surfaces are dry before moving on to the next step.

Flexpert Tip: Smooth out any rough spots or remove old paint with sandpaper or a scraping tool. To remove old caulk, use a razor blade or caulk removal tool.

2. Seal Cracks and Gaps with Flex Caulk

Flex Caulk is perfect for sealing cracks, gaps, and joints around windows, doors, and seams where water is most likely to infiltrate. Caulking these areas is crucial for maintaining the integrity of your shed’s structure and helps keep pests out too.

After the residue has been removed and cleaned, grab your Flex Caulk, break off the tab and remove the “Snap and Save” cap. Then, turn the “Trigger Flow Nozzle” up and push the trigger. Apply the caulk in a continuous, smooth bead along the gaps around windows, doors, and seams.

Next, use a caulking tool or your finger to smooth the caulk, so the gap is completely sealed. Allow about 24 hours for Flex Caulk to fully cure.

Flexpert Tip: For first time use, hold down the trigger for a few seconds in order for the product to be dispensed. You can adjust the size of the bead by dialing the “Trigger Flow Nozzle” up or down. When you’re finished using Flex Caulk, turn the nozzle all the way down to “Min” and replace the cap.

3. Seal Tight Spaces with Flex Seal Spray

Flex Seal Spray is ideal for reaching hard-to-reach places that might be difficult to treat with a brush or caulk. This rubberized sealant creates a waterproof coating that seeps deep into surfaces to effectively seal out moisture.

To seal areas of your shed with Flex Seal, shake the can well and hold it about 8 to 12 inches away from the surface. Spray in an even sweeping motion, making sure to cover corners, edges, and small cracks. Apply several coats, allowing each layer to dry before adding the next.

Flexpert Tip: If you can see light shining through, the area is not completely sealed, and you’ll need another coat. To ensure clean lines, lay blue painter’s tape around the area being repaired.

4. Seal Large Surfaces with Flex Seal Liquid

Flex Seal Liquid creates a durable, waterproof barrier over large areas like walls, roofs, and floors. Sealing these areas provides a strong foundation for keeping moisture out.

Next, use a brush or roller to apply a generous, even coat to the shed walls and roof, working it into any cracks or gaps. Allow 24-48 hours for the first coat to dry completely, then apply a second coat for added protection. When using Flex Seal products on the interior of the shed, open all doors and windows, and consider using a fan for proper ventilation. We also recommend that you waterproof the exterior of the shed to ensure a more effective result.

Flexpert Tip: Flex Seal Liquid cannot be painted over. However, you can paint the shed with high-quality oil-based paint and then apply Flex Seal Liquid Clear on top.

And that’s it. Follow these steps and your shed will be sealed, protected, and ready to handle the tough conditions of the great outdoors. Together, you and the Flex Seal Family of Products are a DIY dream team, so grab some Flex Seal and get sealin’.