Below Grade

Manage thermal loads

The materials and components within a below-grade wall or slab-on-grade assembly form a series of layers intentionally designed and installed to resist water, air, thermal and water vapor loads on the wall or floor.

Insulation products such as stone wool insulation contribute to managing thermal loads through the exterior foundation and underslab assemblies, resulting from conductive heat flow across the building enclosure. Thermal insulation is most effective in these systems when thermal bridging is minimized via insulation continuity.

Benefits

  • Vapor permeable, will not trap moisture against the structure
  • Moisture resistant, providing consistent performance
  • Made from stone providing resistance to termites
  • Maintains its performance over the life span of the building

Application

Underslab

Concrete slab insulation between the ground and the floor is vital to create a comfortable living environment. Not only does it make a building more energy efficient, but it also helps to create cosy, comfortable and habitable conditions for people living or working there.

Application

Foundation/Basement Wall – Exterior

An exterior-insulated wall assembly is simple and robust and has limited inherent risks. It uses Comfortboard as the continuous exterior insulation to maintain consistent thermal resistance, to resist water absorption and to avoid rot, corrosion or mold and fungal growth on or within the insulation. Exterior-insulated wall assemblies are best suited to new construction projects since they require access to the exterior of the foundation wall.

Application

Foundation/Basement Wall – Interior

Interior-insulated below-grade wall assemblies provide thermal insulation on the interior side of the below-grade foundation wall, eliminating the need to access the exterior of the wall to improve thermal performance. This assembly can reduce thermal bridging with the use of continuous insulation on the interior of the foundation wall and can balance assembly thickness and performance with stud cavity insulation.

Interior-insulated wall assemblies are often the optimal solution for existing basement finishing, renovation and retrofit projects.

FAQ

How much insulation will I need in below-grade applications?

To calculate how much insulation you’ll need, check your local building codes and compare with the thermal performance of the insulation products being used. It’s important to note that ROCKWOOL stone wool insulation should not be used under groundwater level.

Does underslab insulation make a difference?

Under concrete slab insulation at grade can make a significant difference to the temperature in buildings and contribute to savings on energy bills over time.

Can I use ROCKWOOL insulation under a concrete slab/floor?

ROCKWOOL insulation can be applied under a concrete slab/floor for different purposes. It can be used under the ground floor slab directly placed on the ground, it can be fixed underneath a cellar or car park ceiling with visual requirements, or it can be placed below an intermediate floor with a separate ceiling finish. Please contact your local ROCKWOOL office for more detailed information.

Contact a Sales Rep

Product knowledge & expert advice awaits

A ROCKWOOL representative will offer professional guidance on products and applications, tailored to your needs and budget.

Join the R‑Class

High-performance building starts now

The ROCKWOOL R‑Class Builder Program is 100% free. If you’re looking to level up to high-performance builds while building community, sign up today.