A roof-deck, simply stated, is a deck that doubles as a roof, or vice versa. A roof deck has all the properties of a roof without the ugly appearance associated with most types of flat roofing. The two most common types of roof decks are:
- Decks where the top surface is not the waterproof membrane. The top surface is usually ceramic tile, stone, or plain, patterned, or textured concrete. A waterproof membrane lies underneath the finish surface. This is the prettiest kind, but a leak repair often requires complete replacement of the finish surface.
- Decks where the top surface is the waterproof membrane. These are the least expensive to install and maintain.
Finding a leak in a roof deck can take time, but it isn't difficult. Sometimes leaks don't occur at the waterproof membrane, but at adjacent connections. The ticket is to find out where the leak is coming from to determine whether a repair can be made.
Continuous L-shaped metal flashing creates a waterproof seal where the deck membrane meets a wall. Part of the L shape travels vertically, 6 to 8 inches up the wall (beneath the siding) while the horizontal part of the L-flashing protrudes 6 to 8 inches away from the wall (beneath the waterproof membrane). The membrane sticks to the flashing, which extends up the wall beneath the siding to ensure waterproof integrity between the horizontal and vertical surfaces.
Unfortunately, flashings do corrode and rust. However, you can get a flashing to last almost forever by regularly cleaning and painting it.
Scuffs, scrapes, and lime deposit build-up can cause a roof deck to appear worn and tattered. So can cracked and chipped grout. Also, leaves and other debris are not only unsightly, but can prevent proper watershed or clog a drain, causing water to back up into the house. Here are a few tips:
- For tile decks, repair cracks and gouges in grout and seal the entire surface with a high-quality silicone sealant. This won't prevent a leak, but the deck surface looks better longer.
- For stone decks, repair cracks and gouges in mortar and seal the entire surface with a high-quality silicone sealant. This won't prevent a leak, but, again, the deck surface looks better longer.
- Keep drains free and clear of debris to prevent flooding.