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Roof sealing made easy

Dizzying heights: Finding the best roof sealants

If your roof starts leaking, you should act quickly. You need to select the right roof sealant and, above all, find a product that can withstand the unpredictable British weather. This guide shows you how.

The Best Roof Sealant for Mild or Moderate Damage

Locating the source of a leak in your roof can be challenging, but there’s no getting around it. Once you’ve found the source of your problem, you will need to find the proper product to repair it. Roof sealant is your best option for repairing small to mid-sized leaks if you need to prevent water seepage or plug holes and cracks; larger roof leaks may require more complex solutions.

When you’re looking for the leak, you need to remember that water travels. This means the water you see and the actual leak may be located in two entirely different places. Your best option is to start looking for your leak in the attic space. Look for black areas or mould, as they are usually the most reliable indicators of leaks. Make sure to check outside as well. Examine the roofing area and keep a look out for misplaced tiles, standing water, mould build-up, or rotting areas in flat sections of your roof. Most roof leaks involve construction elements that pass through the roof, such as chimneys and roof vents.

You can easily repair small holes and gaps caused by objects that pass through your roof. We recommend using UniBond Roof & Gutter Sealant.

Repairing roofs with sealant

If you’ve found a small leak, you can start filling it with roof leak repair sealant. If you need to carry out a larger repair, you can apply the product to new joints and materials as you see fit. Before you apply the product, you need to make sure that the joint in question is dry, clean and free of debris. You should also make sure it is structurally sound. Note that roof repair sealants are flexible, but are not intended for adhesive purposes. If you need to bond material to your roof, you should consider UniBond Extreme Repair Sealant, which is designed for outside cladding as well as wooden frames.

Follow these steps to repair a roof leak with roof repair caulk or sealant:

  1. Gather the tools you need. These include a razorblade, gloves, a cartridge gun and the roof sealant.
  2. Make sure the area is not rotting and is generally in good condition. Replace any rotting material with new material.
  3. Identify the problem. Look for cracks in existing sealant because they cause most roof leaks.
  4. Clean the area. Make sure there is no old sealant, loose particles, moisture, tar, asphalt, paint, wax or rust in the area you need to repair. Use a razorblade and solvent spray to remove old material. We recommend wearing protective gloves.
  5. Apply the roof sealant. You need to apply the product with steady pressure and force it into the joint. To achieve the best results, you should protect open products and tools from direct sunlight.


Selecting the right sealant is a critical step in the repair process. Over time, the structures of roofs can shift and flex, which means you’ll need to create a roof seal that can do so as well. UniBond Roof & Gutter Sealant will not tear or rip because it is specially formulated to flex and move with your roof. It is designed to stand strong in typical British autumn and winter weather and provide lasting protection. These properties make it an ideal sealant for heavy-duty outdoor projects.

If you need to create general seals around the home, you can use UniBond Extreme Repair Sealant for most of your jobs. This multipurpose sealant works on both interiors and exteriors and can be used on wood. In addition, it doesn’t stain sensitive surfaces like marble and natural stone.  

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