Roof waterproofing - an overview of effective and durable solutions

The roof is one of the most important elements of a building, and its proper protection against the effects of atmospheric factors such as rain, snow, intense sunlight, and strong winds has a significant impact on the durability and comfort of the building.

Flat roof waterproofing

The waterproofing layer is usually the last layer of the roof exposed to unfavorable conditions and must be characterized by appropriate mechanical resistance due to the presence of various media on the roof that must be serviced.

Flat roof waterproofing methods

Roof waterproofing methods vary in quality, durability and performance parameters:

1. Waterproofing based on bitumen dispersions, most often applied with brushes or brushes.
2. Waterproofing mechanically attached or glued using PVC or EPDM membranes
3. Waterproofing based on felt and   here we have a multitude of solutions, from two-layer systems (underlayment and top layer) mechanically attached or welded to single-layer systems
4. Liquid waterproofing membranes (also commonly known as liquid rubber for roofs), in which the base material can be acrylic dispersion, aliphatic polyurethane (UV-resistant), aromatic (not UV-resistant) and two-component polyurea dispersion 

All of the above-mentioned technologies can be used both in newly constructed buildings, e.g. on concrete roofs,   as well as in the renovation of the waterproofing of flat roofs made of felt.

These technologies differ in price, execution time and durability

But also other parameters such as mechanical resistance, resistance to root growth (this is important in the waterproofing of a green roof), as well as, for example, the degree of light reflection.

Waterproofing of flat roofs on concrete substrates using liquid roofing membranes

One of the most advantageous, in terms of price and durability, methods of waterproofing flat roofs are liquid membranes ( liquid rubber for roofs ).

1.         Neoroof hybrid liquid membrane

A liquid hybrid acrylic membrane is a great budget-friendly solution for those looking for a relatively low price, quick application, and excellent waterproofing properties. Neoroof creates a homogeneous (seamless), flexible membrane that covers hairline cracks and provides complete moisture protection and resistance to standing water on flat roofs. It also provides long-term resistance to ultraviolet radiation and unfavorable weather conditions without the need for additional UV protective layers. It maintains flexibility in temperatures ranging from -35°C to +80°C, ensuring over 15 years of waterproofing durability. Neoroof can be applied manually (brush, roller) or by spraying. Before applying the actual waterproofing, thoroughly prime the substrate using dedicated system primers, such as REVINEX .

The Neoroof-based flat roof waterproofing system is water-soluble and therefore fully ecological.

2.      Neoproof PU W-40 cold-applied liquid polyurethane membrane

Neoproof PU W-40 is polyurethane membrane . It boasts high mechanical resistance, making it suitable for use in areas with higher-than-average roof traffic . Neoproof PU W-40 creates a smooth, seamless surface that is resistant to UV radiation, acid rain, standing water, and other adverse conditions.

• Can be applied in cloudy weather (cures through evaporation, does not require UV radiation),
• Remains flexible in a wide temperature range from -40°C to +80°C,
• Minimum ambient temperature during application 10°C,
• Environmentally and user-friendly (one-component, water-based product),
• The durability of flat roof waterproofing made of Neoproof PU W-40 is over 25 years (reinforced with non-woven fabric)

3.     Cold-applied liquid polyurea membrane Neoproof Polyurea C1

Flat roof waterproofing using a liquid polyurea membrane is the ideal solution for achieving a roof with exceptional durability—over 25 years. The waterproofing will be chemically resistant, UV-resistant, and resistant to stagnant water. Utility technicians can walk on the roof without any problems, as this membrane is highly resistant to mechanical stress. It also boasts a high elasticity of over 400%, guaranteeing watertightness even on roofs subjected to rapid temperature changes, or due to the structure itself or the material used.

Waterproofing of flat roofs on a felt substrate using liquid roofing membranes

One of the most popular technologies for waterproofing roofing felt, which has been worn out by the ravages of time, is the use of liquid roofing membranes .

The use of liquid roofing membranes on flat roofs has the following advantages:

• quick order completion time – it is estimated that roof waterproofing using liquid membranes is approximately four times faster than other traditional methods
• small load on the roof structure . Liquid waterproofing is a maximum of 2.5 kg, and most often 1.5 kg, of additional load on the roof structure, while roofing felt is an additional load of 6 to 12 kg/m2, i.e. for 100 m2 of roof it is from 600 kg to 1.2 T   of additional load 
• high light reflection coefficient SRI = 111, giving the effect of a cold roof and improving the efficiency of the photovoltaic installation
• no joints or seams – no risk of failure or leaks
• Zero water absorption of the surface – this prevents snow from sticking to the surface – making snow removal from the roof easier; in the case of felt, the snow often freezes and it is difficult to remove snow without causing mechanical damage
• high durability of over 25 years and easy maintenance – no need to use fire (welding) or specialized hot gluing devices.

We can waterproof a flat roof with the same membranes we use for waterproofing a concrete roof

So these are:

• Neoroof – hybrid liquid membrane
• Neoproof PU W-40 – liquid polyurethane membrane
• Neoproof Polyurea R  - cold-applied liquid polyurea membrane

Below you will find a table of soil selection and a table of durability of individual systems

Selection of primer for liquid roofing membranes depending on the substrate

Comparison of liquid waterproofing coatings offered by Trokentech