WATERPROOFING MEMBRANES
A blowtorch is used to heat the bottom of the membrane.
As the name implies, these are membranes that arrive at the site in the form of rolls. These are then unfurled and laid on a firm surface. The most common type of sheet based membrane is a bituminous waterproofing membrane. This type of membrane is stuck to the substrate with a hot tar based adhesive using blowtorches.
Bituminous Waterproofing Membrane
Made from a petroleum-based asphalt material and used as an exterior membrane. Used in waterproofing and roofing, it is extremely resistant to water and moisture.
Liquid Waterproofing Membrane
Usually used in the interior, liquid waterproofing has an easy application and is low in odour. You can apply it with a paint brush and offers the best coverage when it comes to membranes.
ADVANTAGES OF SPRAY POLYURETHANE FOAM ROOFING
The benefits of installing a spray polyurethane foam (SPF) roofing system, rather than another roof type, are numerous in terms of installation, performance, cost, and longevity.
Energy Efficient
SPF delivers thermal, air, and moisture barriers to provide the highest R-value per inch, which means the material provides better insulation for the building.
Durability
The durability of SPF surpasses traditional roofing systems. The foam material can expand and contract with the building in accordance with outside temperatures, decreasing the likelihood of cracks and splitting.
SPF Roofing System
After installed, the SPF roof can be walked on without causing damage. If for some reason the roofing system is damaged, there are typically no leaks because the puncture usually doesn’t go through the full thickness of the foam.
Seamless and Waterproof
Since the SPF mixture is applied as a liquid, it can fill gaps, seams, and cracks in the existing roof and substrate. The continuous solid surface does not require joints or seams, removing the most vulnerable area for leaking. SPF roofing can be installed by the technician to level out uneven roofs to reduce ponding water
Environmentally Friendly
Unlike other roofing systems, installing an SPF roof does not produce waste and when properly maintained, SPF roofing systems stay out of landfills.
There are a variety of eco-friendly roofing products, which feature zero ozone depletion potential (ODP), ultra-low global warming potential (GWP) and solvent-free silicone coatings.
polyurethane spray system for roofs
SPRAY POLYURETHANE FOAM
- Before the installation can start, the existing roof (or substrate) needs to be prepared. Rather than stripping the existing roof, the contractor will most likely prepare the substrate by getting rid of all dirt, dust, and contaminants. This can be done with air pressure, vacuuming, or even just sweeping.
The first layer put down by the contractor is the polyurethane foam. This foam is created by combining two liquids (a polyol/resin and an isocyanate) as it’s sprayed onto the existing roof substrate.
As the liquid is sprayed onto the existing roof, it creates a foam that expands 20 times in size to form a solid, seamless foam surface. When the foam has expanded, this layer can be between 1 and 1.5 inches in thickness. Since the polyurethane foam adheres to most common surfaces, it can be installed on any roof slope.
EPS – Expanded Polystyrene Foam Insulation Boards:
Rated at R4 per inch; EPS foam insulation boards are more permeable to air and moisture than XPS, but it doesn’t retain moisture to the same extent because of it’s more closed cell structure and it’s breathability which lets it dry out. Two inches of EPS foam board has a moisture permeability rate of between 60 and 75 ng (1 to1.25 perms), which is on the cusp of qualifying it as a type II vapour retarder, but on the more ‘breathable’ side of the scale which we would probably consider a good thing in most applications.
