PMMA Roof to protect from cooking oil

Agrifood Plant Case Study: The Oil Challenge


For several years, an agrifood plant has been facing a roof degradation problem due to the oil vapours from cooking French fries.

The roofs of potato processing plants are often damaged by oil from deep fryers. It makes its way to the ceiling and degrades certain areas of multi-ply or bitumen-based roofs.

Synthetic roofs were tested in places with high exposure to cooking oil and appeared to hold up well. However, after a year, oily residue and oil contamination made any repair impossible.

The client tested four or five different types of roofing, and none proved to be resistant to grease; after a year, the membranes were damaged and irreparable.

In search of a sustainable solution allowing maintenance and repairs, the company approached SOPREMA in 2016. We then offered our client a waterproofing system made of polymethyl methacrylate (PMMA). 

Since its installation, the roof has been showing very good resistance to maintenance chemicals and cooking oil. In addition, when repairs are necessary, it is possible to reactivate the waterproofing membrane using an appropriate solvent, thus ensuring good adhesion between the new membrane layer and the old one.

SOPREMA's Contribution


Faced with the specificities of the project, SOPREMA suggested using products from the ALSAN RS line, a PMMA-based waterproofing solution. The ALSAN RS system, with its reinforced textured finish, was applied to the project due to its robustness and durability, making it ideal for environments exposed to products that prematurely damage surfaces.

Benefits of ALSAN RS Products 

ALSAN RS products are high-performance and robust liquid resins based on polymethyl methacrylate (PMMA). They are particularly recommended for the waterproofing of restaurant or food processing plant roofs because they are resistant to frying oils as well as to chemicals used to clean excess oil off the roof.

ALSAN RS 230 membranes made of PMMA can also be installed quickly, in addition to offering a curing time of only 15 minutes. This quick setting is particularly appreciated by manufacturers who cannot afford to shut down their facilities for too long. Moreover, it is estimated that one hour of downtime in a plant can cost a company up to $260,0001

In addition, roof details are easy to carry out with this type of membrane, as it is a liquid product that has passed FM Global testing for wind uplift.

Other advantages of the product include resistance to UV rays and a high solar reflectance index (SRI). For some time now, some cities and provinces have been requiring that the roofs—especially those in city centres where the buildings are very close to each other—be white in order to reduce the absorption of the sun’s heat by the roofing membrane as much as possible and thus decrease urban heat island effects. Since the SOPREMA membrane is white (but available in several shades from white to grey), it complies with the standard related to SRI. Additionally, PMMA membranes adhere to multiple substrates (concrete, wood, PVC, etc.).

Waterproofing system made of polymethyl methacrylate (PMMA) applied to the roof of an agrifood plant

Features of the Project

The installation of the agrifood plant’s new roof was divided into several phases in order to respect the client’s budget and to avoid costly plant shutdowns as much as possible. 

The installation was also weather dependent. For example, rain and temperatures that are too low (from -5 °C to -10 °C) or too high (25 °C or more) make the application of the product more complex. And since the area to be covered was very extensive, namely more than 87,116 ft2, the project was split into three phases.

Why Choose SOPREMA?

According to the Project Manager, SOPREMA offers a turnkey solution by managing all aspects of the installation. 

“SOPREMA makes sure that the contractors have their material in hand at the fixed date and that they respect the deadline. If a problem arises, SOPREMA does not take long to find solutions so that the project can resume smoothly.”

The client appreciated that SOPREMA offered a waterproofing solution to all the challenges associated with frying oil. “The team members were very professional, offering support throughout the project. They know their products well and were always ready to help people on site, whether it was the owner of the plant, consultants, or contractors”, summarizes the Project Manager.

Project Description

  • SOPREMA Solution: Waterproofing

  • Surface to be covered : 87 116 ft2

  • Works duration : 2 phases, from 2016 to 2018

  • Use: Commercial

  • Warranty :  MAMMOUTH PLATINUM Warranty (15 to 20 years) and PLATINUM Warranty



  1. Aberdeen Research