Expanded Polystyrene Foam Insulation For Basement Walls
There is almost no mess and the foam isn t itchy like fiberglass.
Expanded polystyrene foam insulation for basement walls. When using foam insulation on basement walls the building code irc requires r 5 for southern states excluding the deep south and r 10 for the rest of the us. I have existing bagged pink fibreglass insulation directly on the concrete now that i will be removing. Widely reported research by dow chemical co. Thank you for this extremely helpful thread.
Attach the tongue and groove insulation boards to the concrete wall with adhesive. In most basement wall situations the foam plastic insulation material will need to be covered by a fire ignition barrier. Rigid foam insulation commonly called styrofoam insulation is made up of expanded polystyrene or eps panels that are secured to basement walls to increase the wall s r value. This is the same stuff your disposable coffee cup and is made out of and it s used to protect fragile items in their packaging.
I will be building a 2 4 wall in front of the foam. Both extruded or expanded polystyrene have been widely used with success. For more information on this issue see joe lstiburek discusses basement insulation and vapor retarders. When this ignition barrier is supported on a stud wall the cavities of this wall may be filled with supplemental insulation.
I am about to finish my basement using 2 xps polystyrene foam on the foundation walls. Polystyrene foam boards commonly called foamboard are a clean lightweight convenient way to insulate bare concrete walls. It provides an r value of 4 per inch of thickness and is the cheapest type of foam board insulation. Estimated savings for r 10 insulation range from 250 in washington dc to 400 in minneapolis.
Follow with a 2x4 frame wall and insulate it with batt insulation. Shows that their extruded polystyrene foam insulation on average outperforms expanded polystyrene eps in below grade insulation applications. For a basement remodeling project consider insulating basement walls with foam board. Basement walls don t need to dry inward so it s ok to use foil faced rigid foam for this purpose.
Although the energy savings of sub slab insulation are not as significant as basement wall insulation such insulations do offer a significant improvement in comfort and moisture damage resistance including against summertime condensation. Half inch gypsum board usually provides sufficient ignition barrier check your local building code. Green builders prefer eps to xps since xps is manufactured with a blowing agent that has a high global warming potential. Use a premade kit for this type of project.
Due to the study s limitations however dow cautions against using the findings to predict long term performance of polystyrene foam insulation board in this application.