Frequently Asked Questions

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Roofing Waterproofing

What distinguishes the different roof waterproofing technologies?

Roofing material
Specialized equipment Ease of installation Sustainability Resurfacing
SBS ++ ++ +++ X
PVC ++ +++ ++  
PMMA +++ + +++ X
Hot rubberized asphalt +++ ++ +++ X

It is a method to apply waterproofing to a structure with one or more layers of prefabricated membranes.

It is important to validate the compatibility between the sealants used and the bituminous substrates because they may be compatible but have poor or no adhesion.

Bitumen and polyether-based sealants are, among others, compatible and efficient.

Butyl and polyether-based sealants are generally compatible with PVC.

Roofing Systems

Technology vs. its renewal method

Roofing material Renewal method
SBS Cleaning and reuse of the existing waterproofing system
PVC Replacement of existing membranes
PMMA Cleaning and reuse of the existing waterproofing system
Hot rubberized asphalt Dismantling of the protection sheet, and reuse of the existing system

In addition to enhancing the aesthetics, flashings make it possible to direct water for better evacuation, to improve the protection of the roof against wind uplift, and to create a transition between two different materials.

  • How to install a self-adhesive base sheet with a weldable surface on a parapet? [Watch the Video]
  • How to weld a cap sheet membrane on a parapet? [Watch the Video]
  • How to install a self-adhesive base sheet membrane on a parapet? [Watch the Video]
  • How to install an adhesive-bonded cap sheet membrane on a parapet? [Watch the Video]
  • How to install a self-adhesive cap sheet membrane on a parapet? [Watch the Video]
  • How to install an adhesive-bonded base sheet membrane on a parape? [Watch the Video]

It is feasible, but not recommended because mortars and tiles are products with different mechanical properties from those of waterproofing membranes. Bonding tiles directly on the waterproofing will affect its integrity during the various climatic cycles.

In general, we recommend laying down a drainage board or protection board before installing any element over the waterproofing.

Both are possible and equally effective. There is no right or wrong way. It depends on the type of construction and the bearing capacity of the structure, as well as aesthetic, functional or fire protection needs.

In addition to replacing existing materials with new and more efficient materials, it is possible to add sprayed or blown insulation (sprayed polyurethane, cellulose, etc.) from the inside of the roof.

The local codes in force give indications on the minimum thermal resistance according to the location of the building.

Depending on the integrity of the existing insulation, it is possible to blow cellulose over existing mineral wool.

Mathematical formula for slope is: x:12 <>%

Good practices for a flat roof indicate a 2% slope minimum, or according to the manufacturer’s minimum requirements.

Today, as the ground is occupied by built surfaces, it can no longer play its role of rainwater regulator. It is important for designers to rethink buildings so that they contribute to better stormwater management in urban environments. SOPREMA offers SKYWATER solutions, a complete line of products that manage and mitigate the effects of rainwater runoff, as well as its SOPRANATURE® line for green roofs.


These are our best products for airborne noise insulation by adding mass:

We recommand the use of those products for the best acoustic insolation.  To improve soudproofing, use impact noise insulation with vibration absorbing materials:

However, it is important to understand that soundproofing is a combination of solutions that can reduce airborne noise and impact noise. Those products can also be used to reduce de noise from one floor to another.

It is possible to use rock wool or fibreglass, but cellulose remains the material with the most advantages for the installer, the user, and the environment.

The acoustic product brochures contain tested assemblies and tables demonstrating their acoustic performance.

Wall Systems

The local codes in force give indications on the minimum thermal resistance according to the location of the building.

A wall is made up of various materials that work together to separate the interior and exterior environments of a building. The use of an air barrier is essential to be able to control air leaks. Air barriers are generally divided into two categories: vapour-permeable and non-permeable. Depending on the type of walls – i.e. exterior insulated wall or hybrid insulated wall – different air barrier materials can be selected. Various moisture management strategies may also be needed.

All layers of the control plane, including insulation, are exterior to the structure. More efficient positioning of the insulation helps reduce the effect of thermal bridging because no insulation is placed in the cavity between the studs. The installation of an air/vapour barrier membrane, also called a non-permeable air barrier, is recommended in an exterior insulated wall assembly. Moisture management of this wall is greatly simplified since the dew point is located outside the non-permeable air barrier.

Characteristics of a non-permeable air barrier:

  • Good resistance to air leakage, water infiltration, and water vapour diffusion
  • Positioning on the warm side of the insulation
  • Contribution to air and vapour control plane

In a hybrid insulated wall, insulating materials are added in the cavity between the studs, thereby shifting the dew point towards the inside. In this assembly, the functions of vapour barrier and air barrier must be provided by two separate products. A vapour barrier is installed on the warm side of the insulation, while a vapour-permeable air barrier is placed outside of the structure.

Dew point from 20 °C to -20 °C

Non-permeable air barrier

Characteristics of a vapour-permeable air barrier:

  • Good resistance to air leakage and water infiltration
  • Diffusion of water vapour
  • Installation on the intermediate cover panel
  • Contribution to the air control plane; the vapour control plane is provided by another product


Depending on the technology and the structure to be waterproofed, the waterproofing material is installed using a roller, a trowel or a squeegee, or by spraying.

It all depends on the needs of the user, designer, installer, etc. We offer systems with different but versatile technologies to adapt to every need.

Technologies associated with the waterproofing of concrete structures, either cold or hot liquid applied (prefabricated elastomeric membranes or fabricated on site), epoxy, polyurethane and PMMA liquid coatings.

Insulation Materials


  • Polyisocyanurate, XPS (extruded polystyrene), and rock wool


  • Polyisocyanurate, XPS (extruded polystyrene), and rock wool


  • Polyisocyanurate (inside) and XPS (inside and outside)


  • Polyisocyanurate for conventional roofs
  • Rock wool for conventional roofs and acoustic needs
  • XPS (extruded polystyrene) for protected membrane (ballasted) roofs


Several combinations are possible depending on the type of wall:

  • Polyisocyanurate for hybrid or perfect walls
  • XPS (extruded polystyrene) for hybrid or perfect walls
  • Spray-applied polyurethane for hybrid or perfect walls
  • Cellulose for hybrid walls


  • Polyisocyanurate for interior foundation wall applications
  • Spray-applied polyurethane for interior applications
  • XPS inside and outside

XPS allows effective, simple and quick insulation of concrete walls because they can withstand the constant humidity of the ground.

Polyisocyanurate is very effective in terms of thermal resistance. It is intended for the interior sides of foundation walls.

Medium-density spray-applied polyurethane is a very effective option but must be covered with gypsum boards.

In all cases, validation by a competent authority makes it possible to choose the right assembly according to the region where the building is located.

It all depends on the desired performance and the complexity of the construction. We offer the most effective insulating materials and dynamic assembly options.

The main limitation of extruded polystyrene (XPS) is its service temperature. Above 74 °C, polystyrene deforms, and in cold weather, its thermal resistance decreases. It can however be used in humid conditions such as underground applications or in places where the sun does not reach it directly (roofs with protected membranes, walls, etc.).

In Canada, polystyrene insulation is subject to classification from the ULC-S701.1 Standard. They are divided into four types according to their physical and mechanical properties.

It insulates primarily against sound and fire. It maintains its thermal resistance in changing weather conditions.

The mass of rock wool absorbs frequencies that fibreglass absorbs less well.

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