Free Shipping

on orders over $1999

Worry-free Returns

365 day return policy


Essential delivery info


ZipUP UnderDeck® Main Rails are a crucial component in creating an attractive watertight underdecking system in your outdoor space. The Main Rail features a specially-designed channel which connects with the beadline built into ZipUP Panels to form a water and rainproof seal. Attaching directly to the Pitch Rails installed on your joists, Main Rails are attached with standard 1 to 1-1/2 inch long deck screws (sold separately). Long-lasting and incredibly easy-to-install, the ZipUP UnderDeck® systems expands your home's living space to include more backyard parties and cozy nights out while adding value to your home.

ZipUP UnderDeck® Main Rails are available in the versatile colors of White, Beige, and Gray, and are offered in both 12 foot and 16 foot lengths.

Estimating materials:
Start here with our handy ZipUP UnderDeck® Calculator  

Determine the number of Panels needed for your system, then subtract 1 to find the number of Main Rails needed.


DecksDirect # 6397

ZipUP UnderDeck® Installation Instructions & Warranty (5.90 MB) 

ColorsWhite, Beige, and Gray
Dimensions (Length x Height)12 ft x 2 in or 16 ft x 2 in
Pack SizeEach
Coverage EstimateSee description above
Included AccessoriesNone
WarrantyView Zip-Up UnderDeck Warranty Information
Soffit Light for Trex RainEscape
Starting at: $69.10
Highlight your deck railing with Recessed LED Down Lights by Dekor in your top or bottom rail.
Starting at: $17.29
Wall Trim - White
Starting at: $37.99
Zip-Up UnderDeck Seam Trim - Beige
Starting at: $42.99
Zip-Up UnderDeck Pitch Rail - 1/2"
Starting at: $47.99
Hardware Kit For ZipUP UnderDeck® Drainage
Starting at: $39.99

Reviews & Questions