Re-Roofing Options For Flat Roofs: Taking A Look At Spray Polyurethane Foam And How Its Applied


If your flat roofing needs to be repaired, you can choose from a wide array of different materials. Spray polyurethane foam roofing come with great recommendations. Unknown to the masses, spray foam roofing composed from polyurethane has been around for more than 50 years, and can last for up to 50 years when properly maintained. If you're looking to re-roof your flat roofing, you should highly consider opting for spray polyurethane foam due to its advantageous properties. This article will explore what spray polyurethane foam is and how it is applied to your roofing.

Taking a Deeper Look At Spray Polyurethane Foam

When looking into roofing materials, most building owners automatically think of materials like concrete, asphalt and bitumen; however, studies have shown that spray polyurethane foam can get the job done in a more efficient and effective manner.

Spray polyurethane foam was first used for roofing purposes in the 1970s after the U.S. military officials recognised its value. Spray polyurethane foam contains a wide array of different chemicals, such as isocyanates, polyols, catalysts and non-ozone-depleting blowing agents. All of these components are mixed together in a liquid solution at the worksite, which causes tiny bubbles to form. The tiny bubbles causes the liquid solution to foam up and eventually harden.

You can choose between two different types of spray polyurethane foam: open-cell and closed-cell. The cells of open-cell foam are not completely closed. This allows a significant amount of air to fill into the "open" spaces. In comparison, the cells of closed-cell foam are completely closed and are packed together tightly. As a result, open-cell polyurethane foam is softer in comparison to closed-cell foam and more permeable to moisture. Closed-cell foam, on the other hand, is denser, impermeable to moisture, and also able to strengthen the structural integrity of the structures that it has been applied to. The type of polyurethane that you choose should be suitable for the environment that you are in and what your roofing structure needs.

Applying Spray Polyurethane Foam for the Roofing

If you are interested in re-roofing your home with spray polyurethane foam, it is crucial that you find a licensed and experienced roofing contractor with experience in this particular field. Some roofing contractors may simply show up, spray the foam all over the roofing and call it a day. This type of re-roofing technique is simply inadequate and insufficient. You will find that problems will begin to emerge with time, and your roofing structure will need numerous repairs. To ensure that the spray foam has been applied properly, you will need to make sure that the roofing contractors have taken the time to properly prepare the roofing through:

  • Surface prep. To ensure that the spray polyurethane foam bonds to the roofing structure properly, you and your roofing contractor should spend a considerable amount of time cleaning up the surface of the roofing. Remove all loose materials. Sweep all of the dirt and debris that have accumulated on the surface and haul away any loose gravel that may be present. For best results, you should use a spudding tool to scrape off any bits and pieces that may be stuck to the surface, a gas-powered blower to dislodge remaining dust, and power washing to achieve a spotless surface.
  • Applying a special adhesion primer to encourage the spray polyurethane foam to adhere to the roofing. Most roofing contractors recommend using an airless sprayer for an even distribution.
  • Completing all sheathing repairs. If any portion of the roofing is rotting, strip that portion of the roofing and replace the framing and sheathing.


Spray polyurethane foam is an optimal choice for re-roofing purposes. The polyurethane material possesses an excellent R-value, has a long service life, and is unlikely to leak although it can be more expensive than traditional options. It can also tolerate extreme and harsh weather environments for prolonged periods of time making it perfect for the various climates in Australia. To determine whether spray polyurethane foam is suitable for your roofing, contact a licensed and professional roofing contractor immediately for a thorough and detailed inspection, as well as an estimate regarding the total expected cost of the project.


22 October 2014

How I Constructed My New Home

Hello and welcome to my construction blog. My name is David and I would like to tell you about the process of designing and building a new home from the ground up. I had always dreamed of building my own home and last year, that dream became a reality. I had been saving money for many years so I could afford to buy the materials and employ the contractors needed to construct my home. I learnt so much during the process, I decided to start this blog. It was a wonderful day when the final piece of my home was put into place and I am now very happy.