How to repair a leaking roof with WATERSTOP Emergency

Need to repair a leaking roof but don’t want the cost of a full roof replacement? Look no further than WATERSTOP Emergency, a waterproof roof coating that creates a quick and effective roof repair, even in wet weather.

This step-by-step guide shows you how to use our roof repair paint to stop leaks and seal gutters to keep your home exterior watertight during the wetter months!

Why use a waterproof roof coating?

Your flat roof and gutter systems are exposed to rain, frost, UV and movement - over time small cracks or leaks can develop. A waterproof roof coating like WATERSTOP Emergency provides a flexible, waterproof barrier that adapts to temperature changes and movement, reducing risk of damp, overflowing or structural damage.

Key benefits

  • Instantly waterproof - works on wet or dry surfaces, even if it’s raining.  
  • No primer required - you can apply directly to felt, tiles, metal, uPVC, concrete, wood or most plastics.
  • Weather-resistant and flexible - resists UV, frost and temperature changes, and won't crack as surfaces expand and contract.  
  • Quick and easy application - brushable roof repair paint, apply straight from the tin.  

Due to its flexibility and instant waterproofing, WATERSTOP Emergency is ideal for gutters, flat roofs, and other external joints. 

Step-by-step: How to fix a roof leak with roof repair paint

Whether your roof or gutter system is made from felt, tiles, aluminium, metal, uPVC or more, you can easily fix a roof leak or gutter leak in just a few steps with WATERSTOP Emergency. 

Instructions

1. Prepare the surface

Note: WATERSTOP Emergency works on most surfaces, except polyethylene & polypropylene plastics, or bitumen coatings. 

  • Clear away leaves, moss, dirt, rust or debris using a brush or putty knife.
  • Degrease and clean away any contaminants to ensure the surface is sound.
  • The coating can be applied when the leaky roof or gutter is damp, but we recommend brushing away excess water - surface should not be puddled.
  • New cement or mortar surfaces must have cured before coating; metal or plastic gutters are fine with standard prep.
  • Protect nearby areas (windows, frames, walls) with plastic sheeting. 

2. Apply the first coat

  • Open the tin, pierce the film and apply immediately to the affected area using a disposable brush - the product starts curing once exposed.  
  • Apply a continuous, even layer over the damaged or leaking area, making sure to cover cracks, seams or joints thoroughly.  
  • For cracks wider than 5 mm, fill them fully.
  • For corners, joints or areas that are prone to movement, embed reinforcing scrim into the first wet coat. 

3. Wait and apply the second coat

  • Allow the first coat to dry (approx. 4 hours at 20 °C) before applying the second coat - it should be dry to touch.
  • Apply a second even layer and leave to fully cure. Full cure typically takes 24 hours under normal conditions, but the repair will be waterproof immediately. 

4. Inspect and test

  • After curing, test the repair with water via a hose or rainfall, to ensure leaks are completely sealed.
  • Check that the coating is continuous, without gaps or thin spots.
  • Reapply a layer of the roof repair paint if the leak persists. 

When and where is WATERSTOP useful?

  • If the leak or crack is unexpected, and you need a quick fix - WATERSTOP Emergency works in the rain or damp conditions.
  • On felt, tiles, metal or uPVC gutters, concrete or masonry surfaces around gutter ends, downpipes or flashing - the coating bonds directly to these substrates without primer.
  • When gutters or roof joints may expand and contract due to temperature changes - the flexible coating resists cracking and remains watertight.
  • For a more durable, weatherproof finish than a basic sealant - especially for larger areas, seams, or multiple cracks. 

Let's sum up!

If you notice leaks, cracks, or seams failing in your flat roof or guttering, using WATERSTOP Emergency waterproof coating gives you quick, flexible, and long-lasting waterproof protection:

  • Suitable for a wide range of materials
  • Can be applied in damp or rainy conditions
  • Durable finish that resists weather, temperature changes and movement

Remember to clean the roof or gutter area thoroughly, brush on two coats of the roof repair paint and allow it to dry - you'll have a watertight seal that will protect your home long-term. 

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