Sheathing & Siding Underlayment

Sheathing and siding underlayment create a stable R-Value energy barrier needed on all frame-type construction. Exterior sheathing lessens thermal breaks caused by studs, headers and rim joists. Molded polystyrene sheathing and siding underlayment provide a flat and level surface for new siding.

Sheathing & Siding Underlayment Products

ACH Foam Technologies' Foam-Control® PLUS+® is an architectural insulation product line with high compressive strengths and R-values. Foam-Control® PLUS+® is a premium insulation manufactured to provide architects, specifiers, distributors, and contractors all the features and benefits inherent in a high quality insulation.  Perfectly suited for wall insulation applications, Foam-Control® PLUS+® is available in 15 to 60 psi compressive strengths with R-values from R4.2 to R4.5. Foam-Control® PLUS+® comes with a 50-year R-value warranty and is available nationwide.


Foam-Control® R-SHIELD® film-faced insulation is a cost-effective, durable, and energy efficient solution for insulated sheathing and siding underlayment applications. It is an ideal material to provide a code compliant air and weather resistant barrier and reduce energy loss through framing members.

Foam-Control MAX™ molded graphite polystyrene is a superior rigid foam insulation that is ideal for any vertical construction application, such as wall insulation, where a high-performance building envelope is desired. Foam-Control MAX™ is a premium-grade insulation developed to achieve an R5 (R-Value) at 1 1/16th inches thick without the decrease in R-value performance associated with XPS over the life of the product.