As an air barrier material, it has demonstrated water holdout capabilities in industry-recognized water resistance tests.
When every penny counts, you can rely on the performance of one of our most economical fanfold siding underlayments. The 0.3" FQ350 is made of extruded polystyrene foam (XPS). Designed to be used as a “leveling board”, it adds insulation and moisture protection during installation of new vinyl siding over old siding. It is configured in fanfolded bundles 4’ x 48’. It comes with crease-fold hinges and a reflective facer on one side for added energy efficiency.
Product Highlights
Reflective facer on one side for added energy efficiency
Lightweight, durable... cuts clean and easy
Perforated to allow moisture vapor to escape
Provides a smooth, level nailing surface for new siding
GreenGuard Q250 Fanfold Underlayment
Economical fanfold underlayment XPS 0.2" thick with crease-fold hingesGreenGuard Q350 Fanfold Underlayment
Economical fanfold underlayment XPS 0.3" thick with crease-fold hinges
