When you live in Washington state, you need a roof that can withstand the local rainy climate without developing moisture damage. There are many ways that rainwater can harm a roof.
A wet roof provides a breeding ground for mold, moss, and algae growth, and water that seeps underneath shingles or roof tiles can cause wooden roof decking to decay or rot. Once roof decking decays or rots, your roof can begin leaking, and a leaking roof may require expensive repairs or a total replacement.
If you plan to replace your roof soon, then read on to learn four tips for designing a moisture damage-resistant roof.
1. Choose the Right Roof Material
Many roof materials on the market are relatively moisture damage resistant.
Metal Panels or Shingles
Metal roofs are great options in rainy climates. Metals are non-porous materials, so they do not absorb moisture, and rainwater sheds off metal roofs very easily. In addition, metal roofs are not as prone to moss and algae growth as many other roof materials are. If these substances do grow on a metal roof, they simply create an eyesore and are unlikely to damage the metal.
There are two types of metal commonly used in roofing — aluminum and steel. Aluminum is naturally rust resistant, while steel roof panels and shingles are coated with zinc to increase rust- and corrosion-resistance. Both metal types are good options for rainy climates.
Slate tile roofing is also a good option in rainy climates. Slate tiles are typically nailed to the roof decking or underlayment instead of glued. While the slate is slightly porous, the rainwater it does absorb evaporates quickly due to the slate’s special attachment technique. While slate roof tiles can be a bit pricier than other roof materials, slate roofs can stay in great shape for years, making this initial investment worthwhile.
Asphalt shingles also work well in rainy climates. While asphalt shingles are prone to moss and algae growth, you can minimize this risk by choosing shingles with a special zinc coating or additive. Zinc can kill moss and algae spores before they begin flourishing on your shingles and damaging them.
2. Choose a Waterproof Roof Underlayment
While not all roof systems support underlayments, you should have one installed over your roof decking if possible. A roof underlayment provides another layer of roof decking protection, and some underlayments are completely waterproof to protect your roof decking from moisture damage if water were to seep under a damaged roof shingle, a damaged roof tile, or through a roof joint.
Your three main roof underlayment options include:
- Asphalt saturated felt. While this underlayment is relatively affordable and water-resistant, it is not completely waterproof as some roof underlayment options are.
- Rubberized asphalt. This underlayment option is completely waterproof.
- Thermoplastic polyolefin (TPO). TPO underlayment is newer in the roofing industry, and this underlayment is lightweight, strong, and completely waterproof.
Some underlayments work better with certain roof types than with others, so discuss your waterproof roof underlayment options with your roofing professional to determine which is best for your roof.
3. Replace and Seal Warped Roof Flashing
Roof flashing is an essential component of most residential roofs. Roof flashing is typically made up of thin sheets of galvanized steel, copper, or aluminum, and these sheets are placed on areas of your roof most susceptible to water damage and roof leaks. Flashing is typically installed over or between roof joints, along roof valleys, and around chimneys.
Over time, flashing can become warped or develop cracks or holes that reduce its ability to protect your roof and home from water leaks. In fact, many experts believe that up to 90 percent of all roof leaks occur due to problems with roof flashing.
To prevent roof leaks due to faulty flashing, have your current flashing replaced when you have your new roof installed, and then have this flashing inspected on a regular basis to have flashing problems detected and repaired before roof leaks occur.
4. Consider a Waterproof Roof Coating
While not all roof materials can be covered with waterproof coatings, coatings can be an additional protection for your roof. Asphalt shingles, wood shingles, and clay tile are all good candidates for application of a waterproof sealer due to the natural porosity of these materials.
While waterproof roof sealants all vary, most are applied to a roof after all shingles and tiles are laid. A sealant forms a thin, clear waterproof membrane over the enter roof to keep water from penetrating into roof materials. Some also protect roof materials from UV ray damage.
If you live in Washington state and plan to replace your roof soon, then be sure you choose a new roof that is as resistant to water damage as possible. When your roof is designed properly, you can reduce the risk of moss and mildew growth on your roof and also avoid the risk of roof deck water damage. Contact the roof experts at A-1 Roofing Inc. to discuss new roof installation today.