Renovate a plex wall to wall, with ISOFIB's insulation and waterproofing products

Insulation, waterproofing: the energy-efficient renovation of an old building requires adapted materials and a quality implementation. Here is the story of a project to upgrade the envelope of a semi-detached duplex located on the Plateau in Montreal.

Small multi-residential buildings, duplex or triplex type, built in the 1940s and 1950s are extremely common in Quebec: characteristic architecture, brick walls and log structure, limited or no original insulation, very leaky windows...

When they have not undergone major renovations, such buildings present major energy consumption issues. It is exactly in this context that the architect in charge of giving a second life to the adjoining plex built in 1940, located on the Plateau-Mont-Royal, in Montreal, contacted ISOFIB. Here is the diagnosis of ISOFIB's consultants.

Insulate non-dividing walls from the inside, with NatureChanvre panels

First tip: improve the insulation of the roof and walls. The poor energy efficiency of the urban duplex required a drastic upgrade. The classic intervention of insulation from the inside was the only realistic avenue, since the configuration of the building and the exterior brick walls left no real opportunity to insulate from the outside. The first step of the project was therefore the complete stripping.

Nevertheless, in the urban context, square footage is scarce, so the team had to adapt to the specifics of the project and the client's needs.

ISOFIB's team demonstrated that it is possible to add insulating value to the building without encroaching too much on the living space. This is where the R-factor of the NaturChanvre panels convinced the project architect: their thermal resistance of R-3.7 made it possible to reach an R-13 factor for the non-dividing walls. Of course, a 5.5-inch wall, which would have increased the insulation to R-20, would have been ideal. But considering that the log structure, typical of Montreal construction, gives the building a good thermal mass, the R-13 value was targeted for the insulation.

The application of NaturChanvre panels is extremely easy: these semi-rigid insulating materials, very versatile, and whose size is standardized, were installed in the interior walls and roof. Their implementation is pleasant, since even if the mechanical resistance of the fiber requires a grinder for cutting, it is not necessary for the workers to wear gloves.

This thermal correction has largely contributed to improving the energy balance of the building. Particular attention was paid to thermal bridges, which were cut to the maximum. And the biobased panels make the difference for the interior living comfort: the thermal phase shift of the hemp fiber, up to 3 times more efficient than conventional insulating materials, considerably increases the capacity of the insulating panels to retain the heat inside the building.

Improving the waterproofing of walls is a cost-effective strategy

Second step of the renovation strategy: optimize the waterproofing to improve the durability of the building. ISOFIB's experts proposed an adapted waterproofing system: the SALOLA membranes. Thus, the Hygromax membrane was applied above the hemp wool insulation to act as a moisture-regulating vapour barrier. This intelligent membrane promotes the transfer of water vapor according to the relative humidity inside the building, controlling the movement of moisture between the interior and exterior. It thus limits the risks of condensation in the walls.

SALOLA high performance membranes respect the 3 envelope rule of a wall:

- they remain the most closed to water vapor diffusion on the interior side. The PERM value should be between 10.8 and 12.9 PERM on the interior side.

- they are more open on the outside and the outer membrane has a permeance of 129 (Permeance expresses the degree to which a material allows the transfer of water vapor. The higher the permeance, the easier it is for vapor to pass through a wall)

- they create a dynamic flow of the same dimension as a cone that opens outwards.

To ensure a complete seal, SALOLA Blue Aerotape Premium was used to seal the membranes and their clips. This type of adhesive tape, formulated with acrylic without volatile organic compounds (VOCs), does not dry out, even over time, so unlike conventional products that lose adhesion over time, SALOLA tapes offer better adhesion over the long term.

Convinced by the performance of SALOLA membranes, the project architect opted for the full range of waterproofing products for the installation of windows, but also plumbing and electrical ducts.

More than materials: expert advice from ISOFIB

To accompany the insulation and waterproofing works of this project, the experts of ISOFIB gave all the necessary advice to the architect. Convinced that the understanding facilitates the implementation in the rules of art, they put their competence in building mechanics at the service of each of their customers.

What exactly is ISOFIB's service? On a major project such as this one, where the customer buys the insulation and the waterproofing system, the ISOFIB advisor spent more than an hour on the site to present the details of the implementation of the selected materials and products.

In this construction site, the customer appreciated his experience: working with ISOFIB products convinced him that it is quite possible to optimize the building envelope with healthy and performing materials and products, by applying them in a quite standard way, in a conventional renovation. No special training is required!

For more information on our products and to obtain a quote, fill out the online form or call the ISOFIB team at (514) 553-7256.

Find out which products are discussed in this article:

NaturChanvre panels

Hygromax membrane

Aerotape Premium Blue