Polyguard

Polyguard Deckguard HT Roof Underlayment 3' x 75' Roll

Polyguard Deckguard HT Roof Underlayment 3' x 75' Roll

$240.79
  • SKU: POL DGHT36
  • UPC: 655691511054
  • MPN: DGHT36
  • Availability: Ships from the manufacturing facility the next day if ordered Monday to Thursday by 1 PM EST.
  • Shipping: Free Shipping
Availability: Ships from the manufacturing facility the next day if ordered Monday to Thursday by 1 PM EST.
In Stock!
Current Stock:Only left:
Description

Deckguard® HT is a 40-mil high-temperature roofing underlayment membrane designed for sloped roofs in extreme climates. It consists of a premium asphalt compound laminated to a high-strength, anti-skid spider web backing, with a film release liner for easy application. Once applied, the membrane bonds tightly to the roof deck and self-seals around fasteners to prevent water intrusion from ice dams or wind-driven rain.

Features & Benefits

  • High Heat Resistance: Withstands up to 260°F for 60 days
  • Self-Sealing: Seals around nails and fasteners to help prevent leaks
  • Slip-Resistant Backing: Anti-skid surface ensures safer installation
  • Easy Application: Release liner allows smooth, accurate placement
  • Flexible Use: Ideal for valleys, eaves, skylights, ridges, and penetrations
  • Waterproofing Barrier: Guards against ice dams and wind-driven rain
  • UV Exposure Limit: Stands up to 60 days of exposure without degradation
  • Excellent Adhesion: Best results with 650 WB or ClearBond adhesives

Technical Data

Thickness: 40 mils
Film Color: Blue/White
Softening Point: 260°F (ASTM D36)
Elongation: >184% (ASTM D412 Modified Die C)
Tensile Strength: 338 PSI (ASTM D412 Modified Die C)
Puncture Resistance: >22 lbf (ASTM E154)
Low Temp Pliability: No effect (ASTM D146)
Permeance: 0.01 (ASTM E96)
Nail Sealability: Pass (ASTM D1970)
Thermal Stability: Pass (ASTM D1970)
Peel Adhesion: >15 lb/in width (ASTM D1970)
Lap Adhesion: >10 lb/in width (ASTM D1970)
UV Exposure Limit: 60 Days
VOC Content: 0 g/L
Coverage per Roll: 225 sq. ft. (36" x 75')

Recommended Applications & Substrates

Deckguard® HT is engineered for high-performance waterproofing in critical roof areas:

  • Sloped residential or commercial roofs
  • Roof valleys, ridges, transitions, and eaves
  • Chimneys, skylights, vents, and pipe penetrations

Approved Substrates:

  • Plywood
  • Wood Plank
  • Oriented Strand Board (OSB)
  • Rigid Insulation Board (for metal roofs)

❗ Not Compatible With: EPDM, TPO, flexible PVC, or highly resinous materials like pitch.

Application Details

  • Surface Preparation:
    • Ensure deck is clean, dry, and free from voids >1/16”
    • Remove dust, nails, and loose debris
  • Primer Application:
    • Use 650 WB Adhesive (350–400 sq. ft./gal) or
    • ClearBond Adhesive (250–300 sq. ft./gal)
    • Allow to dry tack-free (~30 minutes)
    • Only prime areas you can cover within 4–6 hours
  • Membrane Installation:
    • Cut into 10–15 ft. sections
    • Start at bottom of slope; remove liner as you unroll
    • Apply with 3" side laps and 6" end laps
    • Use hand roller to press down and remove air pockets
    • Center in valleys with minimum 6" overlap
    • Use over rigid insulation for standing seam metal roofs
  • Storage & Handling:
    • Store above 50°F (10°C) in a dry area
    • Avoid folding over eaves unless protected with flashing or drip edge
  • Limitations:
    • Do not use under zinc or other corrosion-sensitive metals without ventilation
    • Do not use on EPDM, TPO, flexible PVC
    • Limit direct UV exposure to 60 days