Roof waterproofing is a necessity for any home. Without it, you’re doomed to a life spent combating leaks and trying to recover ruined possessions. It’s an investment that you should prioritize as a homeowner. Not only because it protects the integrity of the structure of your home but also because it increases your comfort.

In this article, we’ll share the various methods of roof waterproofing, including what factors you should consider when selecting an option. You’ll learn the benefits of roof waterproofing and what the installation process looks like.

What is Roof Waterproofing?

As the name suggests, roof waterproofing is a process designed to keep moisture and water from entering your home. We achieve this by using a combination of specialized materials and a meticulous application process. Applied in the right way to the roof surface, we can create a barrier that stops any water from penetrating your roof.

Inadequate waterproofing can lead to dramatic consequences. In some instances, it might appear as black mold or damp. In others, you could face severe leaks or roof collapse. Left unattended, a lack of waterproofing can be incredibly costly.

Types of Roof Waterproofing

There is more than one way to waterproof a roof. Each has its merits, and selecting the right one for your home depends on your requirements.

Liquid Applied Membranes

Liquid applied membranes offer versatile waterproofing and can be applied to a wide variety of roof styles. The membrane is made from a formulation of acrylic or polyurethane. The liquid is then carefully poured over the roof surface so that it can then cure.

Once cured, it forms a single layer of membrane that protects against water damage. Installation is straightforward, and the process lends itself to complex roof designs. That’s because the liquid can easily enter tight areas and gaps.

Bituminous Coating Waterproofing

Bitumen is a form of tar roofing that is made with an asphalt formula. It’s popular due to its affordability and excellent waterproof qualities. There’s also little maintenance required for a bitumen installation.

To apply a bituminous coating, take the liquid tar (be that hot or cold state) and apply it to the area. After leaving time for it to dry and cure, a hard layer is left on the roof. You’ll often find this style of waterproofing on flat roofs, especially on buildings that could suffer from pooling water.

Membrane Waterproofing

Membrane waterproofing achieves a similar outcome as the last two methods but is installed in a different way. Rather than spreading a liquid substance across the roof, this method takes rolls of membrane sheeting and adheres them to the roof.

The sheeting comes in a variety of different styles but the most popular options are EPDM, TPO or PVC. The sheets have their own characteristics. They differ in terms of how easy they are to install, and in flexibility and durability.

This form of waterproofing is particularly popular for residential and commercial buildings with pitched roofs.

Factors Influencing Roof Waterproofing Material

When selecting your choice of waterproofing, you should consider the following:

Roof Design: Some waterproofing methods lend themselves better to certain styles of roofs.
Climate: Some materials are hardier than others and can withstand severe weather. Others also combat UV rays as well as providing waterproofing.

Specific Building Needs: Make sure you consider the use of the roof. Some roofs take more foot traffic than others, and your waterproofing needs to be able to withstand that.

Durability: Materials with a higher level of durability and longevity tend to be more expensive.

Compatibility: Your roofing materials may only work with some waterproofing methods and materials.

Professional Opinion: Always ask a professional before installing any roof waterproofing.

How To Install Roof Waterproofing


  • Clear the entire roof area so that there is no debris and the surface is clean. If it’s particularly bad, you may need professional help. Take a minute to understand roof cleaning costs.
  • Take this opportunity to repair any notable damage. Acting quickly should reduce your roof repair costs.
  • Check that your current drainage is clear and sufficient.
  • If the material you’re using requires priming, apply the primer.


  • For waterproofing that uses a liquid application, take your rollers, sprayers or brushes and spread the liquid. Ensure that you have an even layer across the whole roof surface. There’s a chance you’ll need to apply multiple layers. If that’s the case, leave an adequate amount of time between applications.
  • Bitumen roof waterproofing follows the same process as above. But, it may need heating before use.
  • When using membrane sheeting, lay them down with a slight overlap. You’ll either fix the membrane in place using adhesive, a mechanical method or some ballast.

Inspection and Maintenance

  • Once the waterproofing is installed, make sure you schedule regular roof inspections. This will help you catch any issues before they get out of hand.
  • If you spot any issues with the waterproofing, attend to them immediately. That could include tears in membranes, split seams or punctures.
  • Check that all drainage is clear at the same time.
  • Even if you’re conducting your own inspections and doing your own maintenance, it’s still worth speaking to a professional at least once a year.

What to Look for in a Professional Contractor

It’s important to understand that roof waterproofing is a specialist skill. Not all roofing contractors will be well versed in the nuances that it requires. Check that they fully understand the work required and have appropriate qualifications.

Aim to work with a contractor with a proven track record and many years of experience. Every roof is different, and their wealth of experience will help them deal with unforeseen complications.

Check their reviews on their website and other online platforms. If possible, see if you can speak with one of their customers before committing.

Waterproofing Your Roof

Roof waterproofing is a mandatory process for any property owner. A great deal of waterproofing’s effectiveness is down to preparation and choice of material. The rest is related to the installation. If you’re in any doubt about your ability, this is one of those tasks that should be left to the professionals.

  • Waterproofing is a preventative investment. It costs much less than dealing with the results of water getting into your property.
  • Ensure you select the right waterproofing system for your specific roof.
  • Regular maintenance and inspections will promote the longevity of your installation.

Roof waterproofing is just one of the services that Trenton Roofing offers. Give us a call, and we’ll talk you through the process.

Alex Valentino

Alex Valentino – Vice President

Leading the way for the company’s second generation of family and employee ownership, Alex’s mission is to create lasting relationships built on trust and respect by providing uncompromising workmanship and unparalleled customer service. With a focus on safety and consumer education, Trenton Roofing strives to set the bar for the advancement of the roofing industry and the betterment of our local communities. When he is not working, Alex can be found traveling with his fiancée, watching football or playing a relaxing round of golf with his friends.