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GreenGuard FQ350 Fanfold Underlayment

Economical Fanfold Underlayment XPS

The 0.3" FQ350 has an extruded polystyrene foam (XPS) core with high-impact polystyrene facers on one side with a reflective facer on the other.

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  3. GreenGuard FQ350 Fanfold Underlayment
Economical fanfold XPS 0.2" thick with reflective facer on one side

GreenGuard FQ250 Fanfold Underlayment

Economical fanfold XPS 0.2" thick with reflective facer on one side
Economical fanfold underlayment XPS 0.2" thick with crease-fold hinges
Economical fanfold underlayment XPS 0.3" thick with crease-fold hinges

GreenGuard Q250 Fanfold Underlayment

Economical fanfold underlayment XPS 0.2" thick with crease-fold hinges

GreenGuard Q350 Fanfold Underlayment

Economical fanfold underlayment XPS 0.3" thick with crease-fold hinges
Kingspan GreenGuard FQ350 Fanfold Underlayment on a transparent background.

GreenGuard FQ350 Fanfold Underlayment

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 the installation of new vinyl siding over old siding. It is configured in fanfold 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