What is Roof Waterproofing Membrane?
A roof waterproofing membrane must be strong, flexible, tear-resistant and elastic so that it can stretch to cover cracks and also move with the building. If the membrane is to be exposed to the sun, then it should be UV stable. The membrane should be flexible enough to take any shape it is laid over, and be capable of turning up and over walls and other construction features. Selection of the right Waterproofing membrane, therefore, becomes pivotal. A waterproofing membrane could be laid above the structural slab and below the finish tiles. This will ensure that water does not seep into the structural slab.
Properties of a roof waterproofing membrane
There are certain properties that a roof waterproofing membrane must have to counter the external challenges. Some of them are;
- UV stable
- High elongation
- Breathability
- Abrasion Resistance
- Chemical stability
Different types of roof waterproofing membranes
Polymer-modified bitumen membrane for roof
The polymer-modified bitumen sheet membrane provides additional flow resistance that makes it possible to use the material in a very hot climate. On the bottom side, the material is covered by a polymer film with special graphic elements, melting of which indicates the proper material heating. On the top side, the material is covered by a polymer film. Modern products are designed for installation as the bottom layer in a double-layer roofing system on buildings and constructions, for waterproofing of foundations and engineering structures. It can be used as an underlay for bitumen shingles on pitched roofs. Used for new construction or repair.
Self-adhesive modified bituminous membrane for roof
Self-adhesive modified bituminous membranes are generally packaged and stored in cardboard boxes or they are protected with opaque wrapping. Unprotected self-adhesive products should not be stored in direct sunlight since exposure to ultraviolet (UV) rays may affect the adhesive properties, especially on the outer convolutions of the roll, or cause “dog-legging” of the roll. Storage for extended periods or under extreme conditions can alter the adhesion properties of the self-adhesive bitumen or affect roll alignment. Self-adhesive modified bituminous membranes are composed of asphalt, polymers, and tackifiers, and may contain mineral stabilizers.
EPDM membrane for roof
EPDM membranes are installed using bonding adhesives. The installation is quick and more importantly, safe. Modern products come as a single component cementitious, polymer-modified non-reactive selective fiber-reinforced repair mortar to provide excellent properties as well as resistance to corrosion and carbonation and shrinkage cracking. This can be applied in thickness from 10 mm to 40 mm in vertical and 25 mm in an overhead situation. It is suitable to apply by hand trowel or by special mortar spray machine.
Thermoplastic membranes for roof
Thermoplastic roof membranes set themselves apart from other commercial roofing systems. It is a blend of polypropylene, ethylene-propylene and is often reinforced with polyester. Sheets of TPO can contain UV absorbers, colorant, flame retardants or other add-ins to achieve required physical properties. Often white, TPO sheets can range in width from 6 to 12 feet and have varying thickness, usually 40 to 100 mil. Thermoplastic membranes can be less expensive than other roofing options. TPO especially is seen as a lower-cost solution when it is time to repair a commercial roofing system.
Liquid applied membranes for roof
Liquid-applied membrane is a monolithic, fully-bonded, liquid-based coating suitable for many waterproofing and roofing applications. The coating cures to form a rubber-like elastomeric waterproof membrane and may be applied over many substrates, including asphalt, bitumen and concrete. There’s no need to strip off old roofing materials and applications can go ahead without any disruption to normal routines within the underlying building. This liquid coating system can be applied by brush, roller, or airless spray directly over the existing failed substrate to reinstate total weatherproof protection.
Bituminous membrane for roof
Hot melt liquid bituminous rubber blend structural waterproofing system with an interlaid reinforcement can be used in roof and podium deck applications to provide a seamless waterproofing membrane for high green roofs and podiums, and are sometimes specified for winter applications as they can be laid at low temperatures.
Polyurethane liquid membranes for roof
Modern products come with a fiber-enhanced one component water-based polyurethane membrane that has been designed for a range of waterproofing applications where the membrane is to be covered over with tiles, screeds, concrete beds etc. They offer excellent adhesion properties overbuilding substrates including concrete, masonry, renders, cement sheeting, wet area sheet surfaces and plasterboard surfaces.
Slip resistant textured membrane for roof
High-build elastomeric membrane is now designed to offer slip resistance to wood and concrete stairs, ramps, decks, docks, patios, sidewalks, and more. The modern day’s unique formula provides long-lasting protection against moisture and the damaging effects of the sun. It is designed to expand and contract along with the substrate while offering excellent scuff resistance.
Conclusion
Modern membrane systems are reliable and durable thermoplastic waterproofing solutions that can fulfill the requirements of even the most demanding below-ground structures, including those exposed to highly aggressive ground conditions and stress. Modern products offer high flexibility of membranes allowing easy installation and completion of details that results in faster membrane installation.