Our home is 10 years old and the asphalt roof shingles are starting to stain badly on the north exposure. Is there something that we can use to clean off the staining and treat the shingles to prevent further staining? -Tim

Hi Tim,

Your stains are probably caused by the airborne spores of a blue-green algae known as Gloeocapsa Magma, which is often mistaken for mold or mildew. While doing little harm to your shingles, the black streaks caused by the algae are unsightly.

Algae can be killed and the stains removed using chemical cleaners, though they usually returns over time. Use a cleaner specially made for killing algae, or by spraying a mixture of one part bleach to four parts water with TSP (trisodium phosphate) or other detergent added in a garden pump-up sprayer. Allow the bleach to remain on for 15 to 20 minutes, then rinse it off with a hose.

Note that bleach may kill or damage plants, so wet down or cover any shrubs or flowers that will come in contact before starting. Repeated use of harsh chemicals or pressure washing can damage or shorten the life of your shingles.

Once the roof is clean, consider installing strips of zinc or copper—which are toxic to algae—along your roof below the ridge. Molecules of the metal will then wash down the roof each time it rains to keep new algae from forming. A better solution is to specify algae resistant shingles, which have copper granules embedded in them, the next time you have your roof replaced.

For more information, check out our article on How to Remove and Prevent Algae Stains on Asphalt Shingle Roofs.

Good luck with your project,

Related posts:

• How to Remove Water Stains from Furniture
• How to Choose a Roof for Your Home
• White Efflorescence Stains on Retaining Walls

It’s important to keep your gutters clean to prevent them from clogging. Elbows in downspouts are the worst culprits, and the flexible metal cable of a plumber’s snake is the best way to clean them out. Insert the end of the snake in the downspout until it meets resistance, then turn the crank and work it back and forth to loosen the clog. Insert a garden hose in the downspout and turn on the water to flush out any debris.

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• The Importance of Keeping Your Gutters Clean
• (685) Family Room Addition: The “Hunt” for More Room
• How to Spring Clean the Outside of Your Home

From natural materials like slate and wood to manmade products such as asphalt, sheet metal, and plastic polymers; there are more types and styles of roofing to choose from today than ever before. While each has its advantages and shortcomings, they all can add a distinctive design element to your home. So which one is right for you?

What to Look for in a Roof

There are many factors to consider when selecting a roof including:

• How long will it last?
• Does it hold up during natural disasters such as wildfires or hurricanes?
• Is it too heavy for the existing roof framing?
• Does the roof have enough slope?
• Will the look complement the style of the house?
• Is the type of roofing allowed by local building codes?
• And finally, how much does it cost?

Pros and Cons

Some types of roofing may be better suited for your house than others. Factors such as the slope of the roof and strength of the framing could limit your choices. In areas prone to wildfires or hurricanes, look for a product with a high fire rating or good wind resistance. In addition, steps can be taken during the installation of many types of roofing to improve their resistance to fire or wind. Below is a rundown on the different types of roofing available.

Asphalt Composition Shingles

Photo Courtesy of CertainTeed Corporation

• The most popular roofing for homes, comprising over 80% of residential roofing.
• Made of either an organic fiber mat (better for cold weather and wind resistance) or fiberglass (more fire and moisture resistant) which is then impregnated with asphalt and coated with mineral granules.
• Available in either traditional 3-tab shingles or thicker laminated “architectural” shingles.
• Algae resistant shingles are available in humid climates to prevent staining.
• Moderate in weight.
• Can be used on fairly low to steeper sloped roofs.
• Good fire resistance, fair wind resistance.
• Inexpensive.

Metal

Photo Courtesy of Metal Sales Manufacturing Corporation

• May be composed of steel, aluminum, copper, or zinc alloy.
• Steel roofs come with either a zinc coating or painted finish.
• Copper roofs are installed unfinished and acquire a protective green patina with age.
• Available in sheets or in shingles that resemble other materials.
• Absorb a third less heat than asphalt.
• Made up of mostly recyclable material.
• Can be installed with the fasteners hidden (standing seam) or exposed.
• Lightweight.
• Available for low or steep sloped roofs.
• Good resistance to both fire and wind.
• Moderate (steel) to expensive (copper) in price.

Plastic Polymer

Photo Courtesy of EcoStar

• Molded from a high-tech plastic polymer material.
• Available in a number of different styles that resemble slate or wood shakes.
• Expected to be long lasting and low maintenance.
• Made from recycled materials and can be recycled again when replaced.
• Light (ArmorLite) to moderate (EcoStar) in weight.
• Can be used on moderate to steep sloped roofs.
• Good fire and wind resistance.
• Moderate in price.

Clay Tile

Photo Courtesy of Ludowici Roof Tile

• Traditional Italian or Spanish look, can also be made to resemble wood shakes or slate.
• Color can fade over time.
• Long lasting and low maintenance, but brittle and can break.
• Heavy, requires reinforced roof framing to support.
• Can be used on moderate to steeper sloped roofs.
• Excellent fire resistance, fair to low wind resistance.
• Expensive.

Concrete Tile

Photo Courtesy of Eagle Roofing Products

• Can be made to resemble traditional clay tiles, wood shakes, or slate.
• Color can be throughout tile or only applied on the surface.
• Long lasting and low maintenance but can break.
• Heavy, requires reinforced roof framing to support.
• Can be used on moderate to steeper sloped roofs.
• Excellent fire resistance, fair to low wind resistance.
• Moderate in price.

Slate

• One of the oldest roofing materials.
• Requires specially trained workers to install.
• Long lasting, durable (varies depending on where it was quarried).
• Heavy, requires reinforced roofing structure to support.
• Steep sloped roofs only.
• Good resistance to fire and wind.
• Very expensive.

Wood

• Available in sawn shingles or split shakes.
• Commonly made of cedar, but can be made of other rot resistant woods as well.
• Gives natural look, weathers to a silvery gray.
• Short lifespan, requires periodic maintenance.
• Moderate in weight.
• Can be used on moderate to steep sloped roofs.
• Good wind resistance, poor fire resistance (can be treated with a fire retardant).
• Moderate in price.

Roofing Comparison

The following table gives an overview of the various materials available. Weight and cost are listed per square of roofing (100 square feet) and include both labor and materials. Actual price may vary depending on the particular product used, the complexity of the job, and labor costs in different parts of the country. The cost per year indicates the price of the labor and materials per square over the roof’s projected life.

Warranties

There are two warranties to consider when roofing your home. The manufacturer’s warranty covers defects in the roofing material. A separate warranty may be issued by the roofing contractor to handle problems arising from improper installation.

A warranty is no better than the company that writes it, so make sure the product comes from a reputable manufacturer with the financial resources to stand behind it. This applies to the roofing contractor as well, since a fly-by-night roofer may be long gone before their guarantee expires.

It is important to read the warranty carefully to see what is covered and excluded. Some warranties are not transferable when you sell your house while others are limited to the cost of materials or are prorated over time.

Your roof is your home’s single most important defense when it comes to protecting it from the elements, so it makes sense to make sure it’s done right.

Related Links

• National Roofing Contractors Association
• How to Hire a Roofer
• Is Your Roof Warrenty Worth the Paper It’s Written On?

Asphalt:

• Asphalt Roofing Manufacturers Association
• CertainTeed

Tile:

• Tile Roofing Institute
• Clay Tile: Ludowici Roof Tile
• Concrete Tile: Eagle Roofing Products

Metal:

• Metal Roofing Alliance
• Metal Sales Manufacturing Corporation

Plastic Polymer:

• EcoStar
• ArmorLite Roofing Technology

Slate:

• National Slate Association
• The New England Slate Company

Wood:

• Cedar Shake and Shingle Bureau
• Goat Lake Forest Products

Related posts:

• How to Remove Black Roof Stains
• How to Repair the Roof on Your Home

I want to install attic vent fans in my roof. Is there a formula on how many you need and the size? -Lin

Hi Lin,

Attic exhaust vent fans can reduce your air conditioning energy costs in the summer as well as prevent condensation and ice dams from forming during the winter. While most are wired into your home electrical system, solar powered vent fans are available that require no electrical hookup. Attic vent fans are designed either to fit over a hole cut in your roof or to mount to the inside of a gable vent.

To determine what size power vent fan(s) you need for your attic, you first need to know the size of your attic in square feet.

Attic Size

To determine the size of your attic, multiply the width by the length of the attic floor in feet. For a single story house, this is usually the same as the square footage of the house itself, plus any attached garage area.

• Example (20’ wide by 50’ long attic): 20’ x 50’ = 1,000 sq. ft. attic space

Vent Fan Size

Next, multiply the square feet of attic space by 0.7 to get the minimum number of cubic feet of air per minute that the fan should be rated to move.

• Example: 1,000 sq. ft. attic x 0.7 = 700 CFM minimum fan rating

Add an additional 20% (CFM x 1.20) if you have a steep roof, and 15% (CFM x 1.15) for a dark roof. Attic vent fans are commonly rated from 800 to 1,600 CFM, making one fans suitable for attics of up to around 2,200 square feet.

Vent Fan Location

Locate roof mounted fans on the back of the roof below the ridge (but not so high as to be visible from the front of the house) in the middle of the main part of the attic. Install gable mounted fans on the gable vent at end of the house faces away from the prevailing winds.

Intake Air Vents

It’s also important to have plenty of soffit or gable vents for the fan to draw air into the attic. To find out if you have enough vent space, divide the cubic feet of air per minute that the fan is rated for by 300 to come up with the minimum number of square feet of intake vent space needed for that size fan.

• Example: 700 CFM ÷ 300 = 2.33 sq. ft. intake vent area

If you prefer the answer in square inches rather than square feet, multiply the answer by 144 and round to the nearest inch (2.33 x 144 = 336 sq. in. vent area).

Fan Thermostat

Set the thermostat on your attic vent fan so that it cuts on between 100° and 110° F. Humidity sensors are also available that cut the fan on if moisture in the attic becomes too high.

Ridge Vents

It’s not a good idea to use a power vent fan if your house has a ridge vent, since the fan will tend to draw in air from the ridge. This works against the natural function of the ridge vent to expel hot air out of the attic as it rises. Also, it’s possible the fan could create enough draft to draw rain in through the ridge vent.

Good luck with your project,

Further Information

• Attic Ventilation
• Attic Venting and Installing Exhaust Fans
• Adding Soffit Vents

Related posts:

• How to Properly Install an Attic Gable Vent Fan
• Combining an Attic Vent Fan with a Roof Ridge Vent
• How to Size a Bathroom Vent Fan

Roof leaks can be hard to find, since they often run down the underside of sheathing or rafters to show up far from their actual source. The best time to try and find a leak is when it’s raining outside, or you can also mimic rain conditions by spraying water on the roof.

Go in the attic and look for damp spots or water stains, trace them back to their highest point, then examine that part of the roof for any potential problems.

Related posts:

• Combining an Attic Vent Fan with a Roof Ridge Vent
• How to Remove Black Roof Stains
• How to Clean and Inspect Your Roof

Keeping your gutters and downspouts clean is an important part of maintaining your home, since rainwater can run over or behind them and rot the eaves if they become clogged.

More information on cleaning and repairing gutters can be found in our article The Trouble with Gutters and video How to Clean Gutters.

Related posts:

• How to Unclog and Clean Downspouts on Gutters
• How to Choose Gutters for Your Home
• How to Spring Clean the Outside of Your Home

          Remove nails                     Replace shingle                   Nail in place

Replacing a damaged shingle:

• Use a flat pry bar under the shingle to break the seal.
• Remove the roofing nails that are holding it in place.
• Slide out the old shingle.
• Nail a new one in place, making sure the nails are covered by the shingles above.
• Replace any nails you removed from the shingles above the damaged one.
• Reseal the shingle tabs with roofing cement and coat any roofing nails.

          Remove nails                  Take out old vent                 Attach new vent

Replacing a damaged roof flange:

• Remove the shingles around the vent.
• Pull out any nails that are holding the flange in place.
• Slide the old flange up over the pipe.
• Nail a new flange in place.
• Reattach the shingles around it.
• Bend the lead casing over the inside of the vent pipe to keep water from running between the pipe and flange.
• Flanges are also available with a rubber gasket that seals around the outside of the pipe.

                      Remove rust                                           Paint flashing

Repairing roof valleys:

Be sure to clean roof valleys regularly. If the valleys are rusty, clean them with a wire brush and apply rust inhibiting paint.

Related posts:

• (689) Your Home and the Weather
• How to Remove Black Roof Stains
• How to Choose a Roof for Your Home

It’s important to clean and inspect your roof regularly, since roof leaks can cause major damage to your home including water damage, rot, and mold. If the roof is high or steep, consider inspect it from the ground using binoculars.

Start by cleaning the roof of leaves, limbs, or any other debris, paying particular attention to problem spots like chimneys, dormers, and valleys. Next, inspect the flashing for damage. Use masonry caulk to seal gaps where the flashing attaches to bricks and urethane caulk to repair the flashing itself.

Related posts:

• How to Spring Clean the Outside of Your Home
• (689) Your Home and the Weather
• How to Repair the Roof on Your Home

From leaky roofs to wind damage, the weather can affect your home in many ways.

Inspecting Your Roof

It’s important to clean and inspect your roof regularly, since roof leaks can cause major damage to your home including water damage, rot, and mold. If the roof is steep, inspect it from the ground using binoculars.

How to Repair Flashing

                      Remove rust                                           Paint flashing

Start by cleaning the roof of leaves, limbs, or any other debris, paying particular attention to problem spots like chimneys, dormers, and valleys. Next, inspect the flashing for leaks. Use masonry caulk to seal gaps where the flashing attaches to bricks and urethane caulk on the flashing itself. If the flashing or valley is rusty, clean it with a wire brush and apply rust inhibiting paint.

How to Replace a Roof Shingle

          Remove nails                     Replace shingle                   Nail in place

To replace a damaged shingle, use a flat pry bar to break the seal, then remove the roofing nails holding it in place. Slide out the old shingle and nail in a new one, making sure the nails are covered by the shingles above. Replace any nails you removed from the shingles above the damaged one, and reseal the shingles with roofing cement.

How to Replace a Roof Vent

          Remove nails                  Take out old vent                 Attach new vent

Roof flanges around plumbing vents can become damaged when squirrels sharpen their teeth on the lead flashing. To replace, remove the shingles around the vent, and pull out any nails holding the flange in place. Slide the old flange up over the pipe, nail a new one in place, and renail the shingles around it. Bend the lead casing over the inside of the vent pipe to keep water from running between the pipe and flange. Flanges are also available with a rubber gasket that seals around the outside of the pipe.

Proper Foundation Drainage

Rainwater that doesn’t drain away from your foundation can lead to moisture problems in basements and crawlspaces. To prevent this from happening, check to see that the ground around your house slopes down at least 6” over a distance of 10’. Add an extension on gutter downspouts to direct water further away from the foundation, and make sure that borders on flower beds allow rainwater to drain away from the house.

Keeping Your Gutters Clean

In addition to roof leaks, rainwater can rot the eave boards on your house if the gutters or downspouts become clogged, allowing water to run over or behind them. More information on gutters can be found in our article The Trouble with Gutters and video How to Clean Gutters.

How to Protect Windows

        Measure window             Cut plywood to size         Attach plywood to window

Extreme winds can damage your home, with windows and roofs being the most vulnerable. Covering windows with 1/2″ to 3/4″ plywood is the least expensive way to protect them from wind and flying debris. Measure the size of the window opening, and cut the plywood 1/2” smaller than the total size. Attach the plywood to the window with screws or spring clips.

 Attaching fabric storm panel to window     Plastic storm panel held by spring clip

Other options for protecting windows include fabric panels and plastic panels, which weigh much less, allow light into the home, and are easier to put up than plywood.

How to Reinforce a Garage Door

          Garage reinforcement kit                         Reinforcing door with 2×4s

Garage doors can also be damaged by high winds. Metal reinforcement kits are available that attach to the concrete slab and the framing above the door. You can also make your own reinforcement using 2×4s. Unplug the garage door operator when the reinforcement is in place.

Home Back-Up Generators

Since extreme weather can disrupt power to your home for days or weeks, many homeowners keep a back-up generator on hand for emergencies.

Whole house generators, such as those from Generac, are professionally wired into your home’s electrical system and take over automatically when there is a power outage. Whole house generators run on natural gas or propane and require little attention from homeowners.

While portable generators are a less expensive option, they require set up and fueling by the homeowner, which can result in carbon monoxide poisoning, electrocution, fire, and damage to appliances and other electrical equipment.

Important safety considerations when operating a portable generator include:

• Only operate a generator in the open at a safe distance from your home.
• Do not use a generator in an enclosed storage building, garage, carport, basement, crawlspace, or near open windows or doors.
• Never attach a portable generator directly to the wiring in your house.
• Instead, plug electrical devices into a heavy duty extension cord attached to the generator.
• The combined wattage of all the devices plugged into the generator should not exceed the rated capacity of the generator or extension cord.
• Turn the generator off and allow it to cool before filling with fuel.

Other Tips from This Episode

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• How to Repair the Roof on Your Home
• How to Install a Rain Diverter
• How to Spring Clean the Outside of Your Home

Who Can Qualify?

Taxpayers who make energy efficiency improvements to their home during 2009 and 2010 using approved products can apply for a credit on their 2009 or 2010 federal income tax returns. A few of the improvements also qualify for a tax credit when installed on primary, rental, or second homes through 2016.

While the energy efficiency improvement tax credit can reduce the amount you owe on your federal income tax to zero, you won’t receive a larger refund than the total amount of income tax you paid for the year. In other words, if you will already receive a full refund of your federal income tax, you will not benefit from the energy efficiency improvement tax credit.

What Home Improvements Qualify?

In order for an improvement to be eligible for a tax credit, the product used must meet certain government established criteria for energy efficiency and come with a Manufacturer Certification Statement indicating that it qualified.

There are two basic categories of tax credits, each of which allow you to deduct 30% of the cost of the improvement, depending on the type of energy saving products you install:

• Products that have a maximum tax credit limit of $1,500.
• Products with no maximum limit.

$1,500 Tax Credit

The following energy saving home improvements are eligible for a tax credit of 30% of the cost of the improvement, with a maximum limit of $1,500 for both years combined. So to receive all of the tax credit, you would need to spend a total of $5,000. Improvements must be completed and put into service between January 1, 2009 and December 31, 2010 to qualify. You may lump several different energy saving improvements together in the tax credit. Products must be installed on an existing home that serves as the taxpayer’s primary residence. Qualified improvements include:

• Insulation
• Windows and storm windows
• Exterior doors and storm doors
• Skylights
• Energy efficient HVAC systems and furnaces
• Garage doors
• Heat reflective roofing
• Energy efficient hot water heaters
• Biomass stoves (wood and pellet)

30% Unlimited Tax Credit

The following improvements are eligible for a 30% tax credit with no maximum limit. The work must be completed between January 1, 2009 and December 31, 2016. Unlike the $1,500 credit, improvements can be to a primary residence, rental home, or second home. Also, both new construction and existing homes are eligible. Qualified improvements include:

• Geothermal heat pumps
• Solar hot water heaters
• Photovoltaic power systems
• Residential wind energy systems

Product Requirements

To best way to be sure that the products you install meet the requirements for the energy efficiency tax credit is to obtain a Manufacturer Certification Statement stating that they qualify. Here are some general guidelines for each type of product.

Insulation

To qualify for a tax credit, insulation must:

• Be primarily used for insulation purposes.
• Be expected to last at least 5 years or carry a 2-year warrenty.
• Meet 2009 International Energy Conservation Code (IECC) guidelines.

NOTE: Only material costs qualify for the tax credit on insulation. Installation costs are not covered.

Windows, Doors, and Skylights

To qualify for a tax credit, the NFRC approved label on the product must state that it has:

• U-Factor of 0.30 or less.
• Solar Heat Gain Coefficient (SHGC) of 0.30 or less.

Deciding whether storm windows and storm doors qualify is more complicated, since their energy efficiency ratings must be combined with the IECC rating and climate zone of the window or door they cover.

NOTE: Only material costs qualify for the tax credit on windows, storm windows, doors, storm doors, and skylights. Installation costs are not covered.

Heating and Air Conditioning Systems

To qualify for a tax credit, HVAC systems must meet the following minimum energy efficiency rating or higher for Energy Efficiency Ratio (EER), Seasonal Energy Efficiency Ratio (SEER), Heating Seasonal Performance Factor (HSPF), and Annual Fuel Utilization Efficiency (AFUE):

• Split Air Conditioner: EER 13 & SEER 16.
• Package Air Conditioner: EER 12 & SEER 14.
• Split Heat Pump: EER 12.5, SEER 15, & HSPF 8.5.
• Package Heat Pump: EER 12, SEER 14, & HSPF 8.
• Gas or Propane Furnace: AFUE 95.
• Oil Furnace: AFUE 90.
• Gas, Propane, or Oil Hot Water Boiler: AFUE 90.
• Geothermal Heat Pump: Must meet Energy Star requirements.
• Biomass Stove: Thermal efficiency rating of 75%.

NOTE: Both installation and material costs qualify for the tax credit on heating and cooling systems.

Garage Doors

To qualify for a tax credit, a garage door must:

• Be installed on an insulated garage.
• Have a U-Factor of 0.30 or less.
• Solar Heat Gain Coefficient (SHGC) of 0.30 or less.

NOTE: Only material costs qualify for the tax credit on garage doors. Installation costs are not covered.

Heat Reflective Roofing

In order to qualify for a tax credit, roofing must:

• Meet government Energy Star requirements for heat reflective roofing.
• Be expected to last at least 5 years or carry a 2-year warrenty.

NOTE: Only material costs qualify for a tax credit on roofing. Installation costs are not covered.

Hot Water Heaters

To qualify for a tax credit, hot water heaters must:

• Gas, Oil, or Propane Water Heater: All Energy Star approved tankless models. No storage tank models qualify.
• Electric Heat Pump Water Heater: Energy Star approved models.
• Solar Water Heater: Energy Star approved models that are not used for swimming pools or hot tubs.

NOTE: Both installation and material costs qualify for the tax credit on hot water heaters.

Solar and Wind Power Systems

In order to qualify for a tax credit, solar and wind powers systems must:

• Provide electricity for the residence.
• Meet required fire and electrical code requirements.

NOTE: Both installation and material costs qualify for the tax credit on solar and wind power systems.

Products that Do Not Qualify

The following items are not covered under the tax credit:

• Ceiling fans
• Clothes washers and dryers
• Dishwashers
• Electric tankless water heaters
• Programmable thermostats
• Refrigerators
• Room air conditioners

For more information on whether a product qualifies for the energy efficiency tax credit, contact the manufacturer. For detailed tax information, contact the Internal Revenue Service at 1-800-829-1040 or your tax accountant.

Further Information

• Federal Tax Credits for Energy Efficiency (Energy Star)
• Consumer Energy Tax Incentives (Dept. of Energy)
• American Recovery and Reinvestment Act (EERE)

Related posts:

• On the Road for Energy Efficiency
• How to Claim the Federal Homebuyer Tax Credit for Existing Homeowners
• (702) Four Step Energy Makeover: How to Make Your Home More Energy Efficient