Exterior Basement Insulation

Protect Your Foundation

Insulating the exterior foundation saves energy, protects basement walls from environmental damage and provides a drainage plane for water. Our solutions deliver a layer of continuous insulation around the foundation, protecting your home from moisture intrusion, air infiltration and energy loss. Also, we offer concrete slabs that are cost-effective alternatives to below-grade foundations. Our products create an effective thermal barrier between cold ground and your concrete slab floor, providing long-term energy efficiency and structural durability.

Exterior Basement Applications


Insulation being installed on an exterior wall.

Exterior Basement Insulation

Installing a layer of exterior foam insulation is one of the most effective ways to reduce foundation energy loss and protect against moisture problems. Our rigid insulation solutions help keep the wall warm, reducing the potential for condensation and protecting the waterproof membrane from damage. Learn more by watching this installation video.

Dow STYROFOAM™ PERIMATE™ Insulation is your go-to choice for insulating exterior basement walls.

  • Enhances drainage
  • Insulates, reducing potential for condensation on interior walls
  • Protects waterproofing membrane
  • Provides long-term thermal performance and moisture resistance
  • Provides compressive strength to resist soil and hydrostatic pressures

Used in conjunction with STYROFOAM™ Brand rigid insulation, ENERBOND™ Professional Foam Adhesive provides excellent adhesion between the insulation board and wall. Use WEATHERMATE™ Construction Tape over joints and seams to enhance the building envelope’s resistance to moisture and air intrusion.

Learn more about these brands in this technical bulletin.

Pipe insulation

Sill Plate

Wood sill plates placed on top of concrete foundations often leave gaps that create pathways for unconditioned air to enter and conditioned air to escape.

Dow sealants help you address gaps and cracks in sill plates, minimizing the effects of soil, water, temperature and air on your building foundation and improving the performance and integrity of the entire structure.

GREAT STUFF™ and GREAT STUFF PRO™ Insulating Foam Sealant works across these common household problems.

  • Gaps and cracks
  • Fireblock
  • Pestblock
  • Brand SILL SEAL

GREAT STUFF™ Pro is designed for contractors and larger applications. FROTH-PAK™ Foam Sealant is also ideal for professional contractors using two-component pressurized systems.

Spray insulation being installed in a crawl space

Crawl Space

In addition to being a major source of energy loss, an under insulated or uninsulated crawl space can lead to uncomfortable drafts and cold floors.

Rigid or spray foam are some of the most cost-effective ways to reduce energy loss and increase comfort in your home. Benefits include:

  • A continuous layer of insulation for enhanced energy efficiency
  • Reduced potential for dampness
  • Quick and easy cutting and installation

Our THERMAX™ Sheathing, STYROFOAM™ Brand insulation, and GREAT STUFF™ series of products can protect your investment.

Product Applications

We offer high-performance concrete slab insulations for both under- and over-slab applications.


Insulation installed on a slab foundation on a new construction project.

Under-Concrete Slab

Adding a continuous layer of insulation under the concrete slab foundation creates a thermal barrier between the ground and the heat-conductive concrete. This enhances your overall building efficiency and prevents condensation and moisture buildup that can lead to structural damage.

Dow STYROFOAM™ Brand Extruded Polystyrene Foam insulation is an ideal solution for under slab installations, offering the following advantages:

  • Reduces energy loss between ground and concrete slab
  • Reduces potential for condensation and moisture damage
  • High compressive resistance can sustain heavy loads without damage

 




Insulation being installed at ground level.

Over-Concrete Slab

For buildings with existing foundations, it may not be possible to insulate below the concrete slab. In these cases, adding insulation above the slab is a quick and cost-effective way to improve the energy-efficient and comfort of a building.

Dow STYROFOAM™ Brand Extruded Polystyrene Foam insulation is an ideal solution for over slab installations, offering the following advantages:

  • Reduces energy loss between concrete slab and floor
  • Increases comfort of floor surface
  • Compliments under-slab insulation
  • Compatible with radiant-heating floor designs
  • Easy installation