XPS vs EPS

Name: Guardian
Address: 4401 S Kansas Ave, Milwaukee, WI, 53235, US
Telephone: (414) 226-5619
Price range: $

As seen in the Milwaukee Area

Based on the principles of science and engineering, Dow Styrofoam XPS outperforms EPS, and delivers maximum energy savings.

XPS Performance Data Summary

77% more density. The higher the density:

28% higher R-value

250% higher compressive resistance

Compressive Resistance—the amount of force needed to deform the XPS insulation
The higher the compressive strength, the harder it is to damage the insulation
A higher compressive strength helps keep walls more uniform and straight when placed over existing siding

Effectively handles water vapor permeance

Water Vapor Permeance—the amount of water in the vapor state that passes through a product or system
EPS insulation has a 5.0 perm rating
Vinyl siding has a .05 perm rating
When a substrate is laminated (such as EPS and vinyl siding), it takes on the properties of the lower of the two—which would be the .05 perm of vinyl siding
Dow 3/4″ T&G XPS insulation has a perm of 1.1—it will not trap vapor moisture
Dow XPS is not attached to the siding so it does not take on the .05 perm
By maintaining its consistent perm rating, Dow XPS allows harmful moisture to escape the home
Dow XPS also creates an effective drainage plane, allowing rain and wind-driven water to escape quickly through siding weep holes