Dekfast Poly Washers

What is a Dekfast poly washer used for?

Dekfast poly washers are a roofing-system component from the DEKS line, providing sealing and holding strength for metal-to-wood and metal-to-metal panel fastening. The molded polymer body spreads the screw's load across the panel and helps seal the fixing point, and the 19mm diameter is sized to allow pre-drilling and let polycarbonate skylight and sidelight panels move with thermal expansion, which prevents cracking around the fastener. They pair with almost any #12 roofing screw. A quality washer is central to a long-lasting roof, so match the Dekfast washer to your fastener and follow the panel manufacturer's fixing instructions for best results.

Why choose Dekfast poly washers

• Roofing grade: durable polymer for long-lasting roof systems.
• Seals and spreads load: for metal-to-wood and metal-to-metal panels.
• Thermal movement: 19mm size allows panel expansion and pre-drilling.
• #12 screw fit: works with almost any #12 roofing screw.

Common applications for Dekfast poly washers

• Polycarbonate skylight and sidelight panels
• Metal-to-wood roofing panel fastening
• Metal-to-metal panel installations
• Roofing systems needing thermal movement

For metal-backed bonded seals, see neoprene EPDM sealing washers, and browse every option on the main sealing and cushioning washers category.

Dekfast Poly Washers FAQ

What is a Dekfast poly washer for?

It seals and spreads load in roofing panel fastening, metal-to-wood or metal-to-metal, and is commonly used with polycarbonate skylight and sidelight panels.

Why does the 19mm size matter?

The 19mm diameter allows pre-drilling and lets the panel move with thermal expansion, which helps prevent cracking around the fastener.

What screws does it work with?

Almost any #12 roofing screw. Follow the panel manufacturer's fixing instructions for best results.