Metal Roofs Bring Energy Benefits
QUESTION: My neighbor just installed a new residential metal roof. It looks just like an ordinary roof, but it has a 50-year warranty. Is a metal roof very energy efficient, especially in the summer?
ANSWER: In addition to being very attractive and durable, new types of residential metal roofing (aluminum, copper, steel) are very energy efficient. They are rapidly becoming more popular with a 50% increase in installations in the past year alone.
From the ground, it is often difficult to distinguish the new types of residential metal roofs from standard roofing. Metal roofs are available in many types and designs that look just like standard roofs--shingles, wood shakes, tile, etc. There are also many colors available and some even have a fine sand-like coating like ordinary tiles or shingles.
Residential metal roofing offers many benefits over standard roofing. Although the warranties range from 20 to 50 years, a properly-installed metal roof can last the life of your house. It is strong and resists high winds, insects, mildew and fire. As compared to a real tile roof, a metal roof is much lighter. This is an advantage in new construction.
Metal roofing, especially aluminum, is very energy efficient. Particularly in the summer, a metal roof rejects much of the sun’s heat, which a standard shingle roof absorbs. This can significantly cut your air-conditioning bills and improve your comfort, especially in second-story bedrooms.
Due to its contour, metal roofing is slightly raised from the roof sheathing surface. This creates a shallow air gap beneath it and allows natural air flow to carry away the sun’s heat. Temperature in the attic immediately beneath an aluminum roof (wood-shake appearance) can be 30 to 40 degrees cooler than with standard roofing materials.
The fire-safety aspect of metal roofs is a definite benefit. In fire-prone areas of the country or where houses are built close together, fires are often spread by sparks and embers landing on the roof from a neighbor’s house. A metal roof may lower your homeowners insurance premiums.
Metal roofing is very easy to install. Since much of the metal roofing is supplied in larger pre-formed panels, you don’t have to install each individual shingle. You can install metal roofing directly over one or two layers of old shingles without the expense of stripping off the old roof.
If you have adequate attic insulation, the noise from rain on the roof should not be any louder. As with any roof, you should have adequate attic ventilation to take advantage of the efficiency of a metal roof.
You can write to me for Utility Bills Update No. 202 showing a buyer’s guide (addresses and phone numbers) of manufacturers of residential aluminum, copper, steel roofing, colors and styles available, and product information. Please include $1.50 and a self-addressed business-size envelope to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.
Cause of Checkered Pattern in Glass
Q: I had some very large super-efficient low-E argon gas-filled windows install. There is a checkerboard pattern visible at times all over the glass. What is causing it and what can I do about it?
A: You are seeing a stress pattern caused by the tempering process. It is not uncommon in tempered glass and is usually apparent only when the light strikes the glass at a particular angle. It is often more apparent in very large windows because of a pillowing effect, a slight bowing of the glass.
There is not much you can do about. Contact your window contractor to see if it is worse than generally accepted standards.
Letters and questions to Dulley, a Cincinnati-based engineering consultant, may be sent to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.
