Up on the Rooftop
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Up on the Rooftop

The next time you walk outside, take a moment to gaze up at your roof. What do you see? Do you see even shingles that are all laying flat? Or do you see shingles that are starting to curl and that are covered in moss? You can tell a lot about the condition of your roof just by looking at it. If you are at all concerned about the state of your roof, then your first call should be to a roofing contractor. They can evaluate the situation and recommend repairs or replacement as needed. Learn more about roofing and roofing contractors here on this website.


Up on the Rooftop

3 Methods You Can Use To Seal Your Flat Roof

Lori Silva

Flat roofs have numerous advantages but can be prone to water problems or leakages without preemptive measures. One of these measures is to seal and waterproof the roof. Below are three methods of sealing flat roofs. 

1. Built-up

A built-up roof comprises several layers of materials that effectively seal the roof from moisture intrusion. The number of layers and materials varies. However, the basic layers include:

  • An asphalt layer that comprises the same materials in asphalt shingles
  • A felt layer that is usually fabric reinforced with fiberglass or other organic materials
  • A surface layer of inorganic materials such as gravel 

The top layer should be rigid and heavy to protect the inner layers.

Built-up roofs are durable, energy-efficient, fire-resistant, and low maintenance. However, the built-up roofing weight is only suitable for a strong roof whose structural support can handle the weight.

2. Membranes

Roofing waterproofing membranes are available in different types. Below are the common ones.

Modified Bitumen

A modified bitumen roof resembles and is an evolution of the built-up roof. The material is a waterproof membrane made of asphalt, fiberglass, and rubber or plastic. Different application techniques are possible for modified bitumen membranes. 

  • The installer applies adhesive on the roof surface and then spreads the modified bitumen membrane.
  • The installer welds the membrane on the roof surface.
  • The membrane comes from the factory with an adhesion that helps it stick to the roof.
  • The installer mechanically attaches the membrane onto the roof.

You may need one or more membrane layers for effective waterproofing.


Rubber membranes are typically single-ply membranes manufactured from recycled rubber. The installer applies adhesive over the roof deck and spreads the rubber membrane. Rubber membranes are relatively inexpensive compared to other waterproofing techniques.

3. Sealant

Lastly, you can use sealants or adhesive coatings of different materials to waterproof the roof. Sealants are available in different types, including silicone, acrylic, and polyurethane. Some sealants are water-based, while others are oil-based. Oil-based sealants are better than water-based sealants for roofs that experience water ponding.

Before application, the installer needs to fix roof damages, clean the roof, and let it dry. The surface preparation encourages perfect adhesion of sealant on the roof. In addition, application during fair weather is encouraged to prevent moisture contamination before the sealant dries. The sealants also protect the roof from ultraviolet (UV) radiation damage.

Consult a contractor for the best sealing method for your flat roof. The contractor should also help you regularly maintain the roof, for example, by resealing it. 

For more information, contact a local company like All Coast Roofing LLC.