Installing DuraFlash™

General Installation Guidelines

Vinyl will expand and contract with temperature changes. Every effort should be made to allow DuraFlash™ to move. Basic vinyl siding installation rules apply here.

  • Install all flashings in shingle style starting at the bottom and working up to provide positive drainage
  • Leave ¼” spacing at ends. If necessary, use two overlapping pieces to give full coverage and allow for expansion
  • Eliminate fasteners where possible
  • Do not set fasteners tight
  • Create slotted holes when using fasteners
  • Overlap all horizontal joints 6” and vertical joints 2”
  • Check for compatibility of sealants and other materials
  • Use sealants capable of adhesion to vinyl
  • In areas where extreme temperature changes occur allow room for movement

Note: When working with pressure treated lumber, use fasteners and metal connectors with coatings rated for use with ACQ.

Flashing the Ledger Board

Proper flashing is one of the most important precautions in deck construction. Keeping water out from behind your deck frame and siding is very important. If water were to penetrate, it would not only cause rot damage but it may rust the attachment hardware and cause structural failure. There have been many stories over the past years of decks falling off a house under a party of people. Water penetration is one major reason for some of these events.

In the past, when pressure treated lumber was treated with CCA preservative you could use aluminum or lower grade galvanization (zinc-coated) flashing. But today, because the new chemical ACQ contains a much higher concentration of copper, this causes corrosion between dissimilar metals. When flashing a deck constructed with ACQ preservative, it’s recommended that you use heavily galvanized steel or copper sheet metal.

In areas with extensive snow and ice, you may want to line the house wall behind your deck attachment with a layer of bituminous membrane before you begin your metal flashing.

Flashing exists to divert water from behind the ledger. You can accomplish this in a couple of ways. Most builders have their own methods of proper flashing.

We recommend the following steps when flashing to a surface with siding

  1. First, use a 14” wide roll of flashing tucked 2” underneath the top cut and let that roll hang down and over your bottom cut. We prefer to have a kick out for the water to drip from as shown below.
  2. A second flashing strip should tuck underneath the top cut siding and bend out over the ledger and down one inch in front of it. This will prevent water from getting behind the ledger, and penetrating the house frame.
  3. At a junction of two layers of flashing such as inside and outside corners, just overlap them by 12 inches and seal the lap with silicone.

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