Waterproof surfaces are physical barriers preventing water from passing through a continuous, thin, layered waterproofing membrane. Waterproofing membranes are typically applied below finished tiles or above a flat terrace’s structural slab.
Waterproofing membranes can prevent leaks over the long term because they can expand and move with the building. Percentages of elongation are typically used to calculate this. This guide is all about waterproofing roofing membrane in detail.
Common types of waterproofing roofing membrane
1. An adhesive-resistant modified bituminous roof membrane
Self-adhesive modified bituminous membranes are typically packaged and stored in cardboard boxes or opaque packaging to protect them. Direct sunlight may result in “doglegging” of self-adhesive rolls when exposed to ultraviolet (UV) rays; this can affect their adhesive properties. Under extreme conditions, self-adhesive bitumen’s adhesion properties may be altered, or its alignment may be affected. A self-adhesive modified bituminous membrane and mineral stabilizers are composed of asphalt, polymers, and testifiers.
2. Thermoplastic membranes for roof
There are many advantages to thermoplastic roofing membranes over other commercial roofing systems. Polypropylene, ethylene-propylene, and polyester are blended to make this material. In addition to UV absorbers, colorants, and flame retardants, TPO can be further enhanced by adding other additives, such as UV absorbers.
It is a thin, white material, usually six feet wide and up to 12 feet long. A TPO sheet can be made in a variety of thicknesses, between 40 miles and 100 mils. Other roofing options can be more expensive than thermoplastic membranes. If a commercial roofing system needs to be repaired, TPO is considered a low-cost option.
3. Polyurethane liquid membranes for roof
The modern products are equipped with fiber-enhanced polyurethane membranes, designed for a diverse range of waterproofing applications involving tiles, screeds, concrete beds, etc. They provide outstanding adhesion properties over cement sheeting, concrete, masonry, render, and other building substrates.
Advantages of waterproofing roofing membranes
The pros of waterproofing roofing membranes are many and varied and include:
- It has been proven that these products can last for decades, so they are of exceptional quality.
- In addition, the application process takes only a few minutes and doesn’t create any sound or toxic fumes.
- They will protect the building without compromising the aesthetics since they are available in various neutral finishes.
- Their application range includes sub-soil, box gutters, and flower beds where they are fully immersed in water.
Disadvantages of waterproofing roofing membranes
While there are many pros, waterproofing roofing membranes do have some minor cons, such as:
- Torch-on membranes are relatively inexpensive to maintain, repair, and replace in the long run; however, the initial cost is higher than other methods.
- Installation of torch-on membranes needs to be handled by a professional – you cannot do it yourself.
Applications of waterproofing roofing membranes
- A screed beneath waterproofing results in a severely compromised ability to accommodate movement at bond breaker junctions. When the coating is released from the bond breaker, the compacted screed restricts its movement because there is no active release zone. It is possible to address this by installing a compressible foam rod at the perimeters before applying the screen. Further compromising membrane elongation tolerance is the failure to achieve the required DFT.
- The minimum Dry Film Thickness (DFT) required by most coating manufacturers is different depending on the conditions. In wet areas, 0.6 to 1mm of DFT is required for wall applications and horizontal surfaces. According to the coating material, balcony, podium, pool, and planter box minimums may range from 1.5 to 2mm, while lift pits, pools, and planter boxes may be 2 to 3mm.
- As a result of slumping and soaping of the coating, low viscosity coatings must be applied in at least three coats. In order to achieve 0.99mm (1mm) DFT on horizontal surfaces and floors, three coats need to be applied at 66% solids.