Rigid Panel Insulation

rigid panel insulation diagram

Building Doctors offers rigid foam panel insulation for a variety of applications. Whether you're involved in a deep energy retrofit, a simple energy upgrade, or need rigid foam insulation for a new construction project, Building Doctors has you covered. 

Rigid foam insulation has a number of advantages; while it's not a perfect insulation material for all jobs, there are a many situations in which it's the ideal insulation.

Types  of Rigid Foam Insulation:


There are three basic foam insulation board products on the market produced under several different manufacturer names. The basic types of foam board insulation are expanded polystyrene, extruded polystyrene, and polyisocyanurate unfaced or foil faced.


Expanded Polystyrene Foam 

 Expanded polystyrene foam (EPS) is the least expensive and least used foam board product on the market. This product typically has an R value of 3.6 to 4.0 per inch of thickness. Expanded polystyrene insulation is similar to the foam used for packing “peanuts” and it’s typically used for insulated concrete forms also known as ICF’s. It is used sometimes on commercial buildings for roof and wall panel insulation, where it is typically sandwiched between light gauge metal.


Cost = Cheapest of the foam insulation   boards.

Expanded Polystyrene Foam


Extruded Polystyrene Foam 

Extruded polystyrene foam (XPS) also known as blue board or pink board comes in many different thicknesses and edge profiles. This insulation board is probably one of the most widely used foam board insulation products in the residential construction industry. XPS has an R value of 4.5 to 5.0 per inch of thickness.



This is the product that I typically use to insulate basement walls. It’s reasonably priced, light weight and easy to use. This product is also used to insulate the outside of foundation walls and even under slabs.


Cost = This product is the middle of the road for these types of foam board insulation products.


Polyisocyanurate and Polyurethane 

Polyisocyanurate also known as polyiso is seen in all kinds of commercial building applications and more recently with residential building projects. Polyiso is typically used with a foil facing and it has an R value of 7.0 to 8.0 per inch of thickness. The reflective foil facing makes it an excellent insulation board when radiant heat is involved. The foil facing also makes it very easy to seal with good quality foil faced tapes.

Cost = Polyiso is the most expensive of the foam board insulation products however it’s the highest R value.

Polyurethane and polyisocyanurate are both closed-cell foams. They contain low-conductivity gases in the cells (usually one of the HCFC or CFC gases.) The higher R-Values (R 7.0 to 8.0) are the result of thermal resistance of the gases in the cells. This can lead to a couple of disadvantages including: off gassing of HCFC or CFC gases, and reduced R Value over time as the gas escapes.

Advantages of Rigid Foam Insulation:

Rigid insulation has a high R-value per inch, so it’s a practical solution for a high R-value where space is limited.

Disadvantages of Rigid Foam Insulation:

They can’t be retrofitted into existing walls without removing the drywall, and are susceptible to the same air-leakage problems as fiberglass batts and blankets. They need to be meticulously installed to limit gaps and air leaks, and they’re slightly more expensive than alternatives.

They can’t be retrofitted into existing walls without removing the drywall, and are susceptible to the same air-leakage problems as fiberglass batts.

We'd be happy to talk with you about which insulation product would be the best fit for your home.

For more information, call 323-646-2534 or email us at info@buildingdoctors.com

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