GreenGuard P Series
Fanfold Underlayment

GreenGuard P1450 Fanfold Underlayment

For use in replacement siding operations to provide a level surface over old siding, add insulation and weather protection

Kingspan GreenGuard P1450 Siding Underlayment comprises ¼” thick closed-cell polystyrene (XPS) with perforated capsheets on both sides. It is configured in fanfolded bundles 4’ x 50’ with cut-n-fold hinges. It is lightweight and easy to cut and install. It is designed to be used as a “leveling board”, added insulation and added moisture protection in installation of new vinyl siding over old siding. Panel rigidity, water-resistance, durability, easy cutting and excellent lay-flat properties make this product the very best fanfold siding underlayment.

Product Information

Typical Physical Properties
Property Test Method P1450
(@ 75oF Mean Temperature)
Water Vapor Permeance
Procedure A
Water Absorption
(max,% by Volume)
ASTM C272 2.0
Fire Characteristics2
Flame Spread
Smoke Development
ASTM E 84/UL 723 25
Dimensions / Packaging
Board Dimensions P1450
Width3 4'
Nominal Thickness 1/4"
Square Feet/Pallet 12,800

1 Specimens were aged and tested in accordance with FTC Rule (16 CFR, Part 460). The R-values shown for GreenGuard-XFP14, GreenGuard-FP38, and GreenGuard-XFP38 are system R-values calculated in accordance with the “ASHRAE Handbook of Fundamentals” using a ½” uniform, parallel dead air space. The R-values of these products installed without the benefit of a dead air space are 1.0 (GreenGuard-XFP14) and 1.5 (GreenGuard-XFP38).

2 These numerical flame spread and smoke ratings are not intended to reflect hazards presented by these materials under actual fire conditions (core data).

3 These dimensions apply to each fanfolded bundle.

GreenGuard P1450 Siding Underlayment_Product Sheet_US_CA_IMG

GreenGuard P1450 Siding Underlayment Product Sheet

GreenGuard Fanfold Underlayment Standard Installation Guide

GreenGuard Fanfold Underlayment Standard Installation Guide

CCRR 1022 1901

Code Compliance Research Report 1022 - Fanfold Underlayment

GreenGuard Reflective Sheathing & Siding Underlayment Safety Data Sheet

GreenGuard Reflective Sheathing & Siding Underlayment Safety Data Sheet

GreenGuard Siding Underlayment, Sheathing & Roofing Cover Board Safety Data Sheet

GreenGuard Siding Underlayment, Sheathing & Roofing Cover Board Safety Data Sheet

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Contact Us

Kingspan Insulation North America

Head Office & Sales Office – North America

Kingspan Insulation LLC

2100 Riveredge Parkway, Suite 175

Atlanta, Georgia



Call: +1(800) 241 4402

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