Today if you are looking for long-term waterproofing solutions for your sundeck, to keep the space under your deck dry for living space or storage, you will most likely go with vinyl decking. It's an engineered floor-covering membrane for exterior use that offers a great option in many situations.
The vinyl decking comes in different colors, and homeowners usually pay attention only to vinyl membrane colour but what about the rest of the deck waterproofing system?
The vinyl deck membranes are designed to waterproof your deck floor surface, but we also have a deck flashing that must "kick" rainwater away from the deck and not let the moisture get between the vinyl membrane and the deck subfloor (plywood).
The most popular and cheapest way for the vinyl waterproof deck edge/flashing finish can be seen in picture #1. This picture shows a typical problem with vinyl waterproof decking when the vinyl membrane edge is glued down the front face of the metal flashing and then secured with a plastic clip.
Over time, the plastic clip expands and falls off the flashing, enabling the vinyl to curl up off the deck flashing, see picture #2. It's happening because of the seasonal weather changes (seasonal movements).
Not only is this unattractive, but it can also cause your deck structure/framing to rot and lead to costly repairs, see picture #3. Unfortunately, the only permanent solution is to replace/rebuild the whole deck with a new vinyl deck covering.
This problem can be solved today by vinyl-coated drip edge flashing, which offers a permanent and efficient solution for terminating perimeter details (picture #4).
This vinyl-coated drip edge flashing is designed to be installed on the deck edge, and the vinyl membrane must be heat-welded to it to ensure a long-lasting finished detail. In the same way, vinyl seams on a deck must be heat-welded. The seam and edge flashing heat-welding system does not require glue and makes a permanent bond between the two materials, creating a waterproof deck.
This way, your vinyl-surfaced deck can last 15-25 years, depending on usage and product quality.