Some of the early warning signs of needing a new roof are leaks, warped or stained ceiling tiles or drywall, and a musty odor from mold.  When water penetrates the roof, it can cause toxic mold to grow in insulation, drywall, and ceiling tiles.  Mold can cause chronic asthma and respiratory infection. Roof leaks can also cause paint to peel on walls, doors, and ceilings.  Another sign that your roof may need replacement are drafts, presence of bacteria and mildew, and heat or cool air loss from the home.  A new roof should be well insulated to keep the AC-cooled air inside during hot summer months, and keep the heat inside during winter months.  A new roof should have a waterproof leak barrier, called decking, that prevents the intrusion of moisture.



Asphalt shingles are the most common type of roofing material used in California. They are made from a mix of sand, cement, and water and are molded under heat and high pressure.  Asphalt shingles are durable, waterproof, and long lasting (up to 20 years).  The shingles are available in a wide variety of sizes and colors. The shingles can fade or be discolored by algae.


Slate shingles are made from natural slate stone.  The shingles are gray colored, fire resistant, impervious to rot, easy to maintain, and long lasting (up to 100 years).  Slate shingles are easily broken by impact, add to roof maintenance, and can clog gutters.


Wood shingles are typically made from Cedar wood, and will last up to 30 years.  They are an environmentally-friendly choice, because they don’t leach any synthetic toxins into rainwater runoff.  Wood shingles are durable, don’t rust, and are easy to repair.


Red clay tiles are often used on Mediterranean style roofs.  Clay tiles are produced by baking molded clay.  There are many colors of tile, including shades of red, yellow, orange and brown.  Terracotta tiles are unglazed clay baked at a low temperature in the kiln. Ceramic tiles are clay tiles with a colored enamel sprayed onto the tile before baking it. High temperatures in the kiln permanently adhere the color to the tile so that it won’t peel or fade.  Clay tiles can crack or shatter if frozen and thawed or in a high wind, but they are generally durable and long lasting (up to 100 years).


Metal shingles are low maintenance, fire resistant, insect and water resistant, lightweight, and environmentally friendly.  The shingles can be painted a variety of colors.  Metal roofs can rust and need regular maintenance. They can also be very loud in rainy weather and need a sound insulating decking to be installed for noise dampening.


Flat roofs are made with hot tar and gravel, single or double ply bitumen, or rubber membrane. Flat roofs must stay watertight, and as such, can require a lot of maintenance. The roof must be regularly cleaned of leaves and debris that prevent clogging of the roof drain and gutters.


Cool roofs are made with a highly reflective paint like coating (or reflective tiles or shingles) that reflects heat.  Cool roofs can stay up to 50 degrees cooler than traditional roofs, which greatly decreases interior temperatures, and reduces the need to run the AC as much.  The cool roof coating or tile comes in a wide variety of colors (not just white), that reflect heat.   For single ply rooftops, the membrane is reflective. For asphalt tile and bitumen sheet roofs, a reflective coating is applied during manufacturing.  For clay tile, the reflective coating can be applied to the tile. For a metal roof, a reflective coating can be applied to the metal.  Cool roofs lower energy costs, and if the product is Energy Star rated, can be eligible for tax credits and rebates.