What homeowners should know about attic ventilation.

Attic ventilation provides a means for airflow throughout your attic space. It is important that the entire space is considered ventilated because if only a portion of the attic space “breathes” then it is no benefit to you.

So why ventilate at all?

There are many reasons sited as reason to ventilate the attic space. The most important reason in my opinion for attic ventilation is moisture control. In fact, this is the reason the attic ventilation discussion began in the 1930’s because as homes became better insulated moisture issues surfaced. Moisture can form in the attic space as the moist air from the house condenses in the attic space. You can sometimes see this in the winter as water droplets form on the nails protruding through the roof deck. Excessive moisture can degrade the life of the roof deck and cause other moisture related problems such as mold.

Ice damming is another major issue that proper ventilation can help resolve. Ice damming is a condition that is created when snow melts at the upper roof, where heat build-up raises the roof temperature above freezing, and refreezes at the lower roof creating a dam of ice. This in turn prevents water from snow-melt to reach the gutter system and instead backup under the roof shingles. This can create leaks in the home and cause considerable damage. Attic ventilation creates an even temperature in the attic space to promote even snow-melt.

Proper attic ventilation can also reduce the overall temperature of an attic. This can help in maintaining cool conditions in the summer time in the upper levels of a home. This can lower the amount of air conditioning required to cool the same space. When talking energy efficiency, attic ventilation should be considered in conjunction with attic insulation.

Another reason often sited for attic ventilation is extended shingle life. It is my opinion that there is not enough scientific research to support this. Shingle color, roof orientation, and geographic location have more impact on shingle life and shingle temperature than attic ventilation. Nevertheless roofing manufactures and organizations continue to beat this drum of extended shingle life and as a result you will find some roof covering warranties require proper ventilation. It would be more accurate to state that proper attic ventilation is needed to maintain roof shingle warranties rather than life expectancy.

So how much ventilation is enough?

The predominate theory and the one prescribed by most code officials is 1 square foot of ventilation for every 150 square feet of attic space expressed as 1/150. Or, if there is a vapor barrier installed under the attic insulation 1/300 is required. This calculation originates from a 1940’s document published by the FHA (Federal Housing Administration). Even though it does not seem to have much basis in scientific research it has persisted to this day and is considered the final word in ventilation requirements.

Types of ventilation.

There are many different ways to provide ventilation and no one method works for every roof type. The types of ventilation can be broken into two major categories; passive and active.

Ventilation needs to address the whole space. This is resolved by the methods applied drawing in airflow from the lower sections of the roof, as in the eaves, up to the upper sections of the roof. Continuous soffit venting, shingle vents, or can-vents can accomplish the lower roof section venting. Ridge vents and can-vents might be used on the upper section. Gable vents are an older approach and not as effective as other means. They also should not be used in conjunction with other vent types.

The previous approaches are all examples of passive venting. Active vents are powered vents with a thermostat and possible a humidistat, wind turbine vents that spin when the wind blows, and fan assisted gable vents.

You should consult a reputable roof contractor or home improvement contractor to determine what will best work with your roof type.

Common problems.

One of the most common problems with attic ventilation, especially in retro-fit situations, is a lack of eave venting. It is common for roofers to sell homeowners a ridge vent but with a lack of eave ventilation it serves no purpose. Other problems with eave venting can include the vents rendered ineffective by painting them shut. In the attic often insulation is blocking airflow. Baffles installed in the attic space can correct blocked airflow by insulation.

Another common problem is an unbalanced system. The quantity of free airflow at the eaves must be balanced with the upper roof ventilation in order to meet the 1/150 or 1/300 design parameters.

In conclusion it is best practice to properly vent attic spaces to prevent problems with moisture, ice damming, and excessive heat build up. (Note there is a hot roof theory that is beyond the scope of this discussion) Most new homes will have some kind of ventilation but that is not to say it has been properly balanced or installed. Many older homes lack ventilation entirely. Always consult with a reputably contractor about your options and do your own research. Then ask a home inspector to verify installation before making your final payment. If you follow these principals you should end up with a good working system.

When Should I Clean My Chimney?

Trying to determine when to clean your chimney or how often cannot be based on a clean set of rules. You must check the buildup of creosote in your chimney to determine this. To do this use a fire poker, when there is no fire, to scrape the inside of the chimney walls. If you find that there is only a thin film buildup, your chimney does not need a cleaning at this time. However, if there is a buildup, then you should have it professional clean. If you find a buildup over ¼” do not use the fireplace until it is serviced. As an added note, please be sure to use proper eye protection and dust mask when do this type of self inspection.

When buying a home with a fireplace it is recommended that you have the chimney inspected prior to purchase. Your home inspector may be able to identify more obvious deficiencies with your chimney but only a CSIA Certified Chimney Sweep can perform a detailed inspection of a chimney. The CSIA (Chimney Safety Institute of America) recommends that any property being transferred that has a chimney have a level two inspection. A level one inspection examines readily accessible areas of the chimney whereas a level two inspection is more in-depth and can reveal hidden hazards.

I encourage you if you have questions about your chimney to visit the CSIA website at www.csia.org and read the homeowner resources.

Is it safe to use rock salt on concrete?

If you haven’t heard it yet you will by the de-icing marketing pros that rock salt can damage concrete drives and walks. However, what you may not know is all de-icers have this potential.

The damage that usually is attributed to rock salt is a spalling of the surface of the concrete. This is more prevalent in new concrete and concrete that is poorly installed. Typically, there are two reasons for this. The first is that concrete is porous and absorbs water. This water freezes in the wintertime and the expansion causes the concrete to crack or spall. The increased introduction of water by melting ice by salts magnifies this problem. The other reason is related to chemical reactions that develop between de-icers and the concrete material or metal reinforcement within that can weaken and/or compound the freeze thaw issues naturally present.

Proper concrete installation reduces its ability to absorb water resulting in freeze thaw damage. This includes proper strength, placement, additives, and finishing. Exterior concrete should be air-entrained (tiny air bubbles); an additive that helps prevent freeze/thaw harm. Finishing can create a surface on the concrete that is weak if done incorrectly. For example if too much water is added during finishing it can spall much easier. If concrete is correctly installed and allowed to cure it typically can withstand more abuse by de-icers.

Conventional thinking is that rock salt (sodium chloride) is the worse de-icer for concrete on the market. Magnesium chloride is sometimes cited as one of the safest de-icer for concrete available. Interestingly in my own research of the subject I found a study by the Iowa State University that seems to run counterintuitive to this thinking. In part it found in testing reaction of de-icers on highway concrete the following:

“Samples were experimentally deteriorated using wet/dry, freeze/thaw, and continuous soak conditions in solutions of magnesium chloride, calcium chloride, sodium chloride [rock salt], magnesium acetate, magnesium nitrate, and distilled water in order to determine relative deterioration activities. Magnesium chloride was most destructive. Calcium chloride was next, and sodium chloride was relatively benign.”

This seems to suggest that the preferred de-icer of some may in fact be more harmful than rock salt. While I am not suggesting the use of rock salt you may not want to regard other forms of de-icers as entirely safe for concrete. Currently it appears that newest de-icer on the market, calcium magnesium acetate (CMA), may be the safest for concrete according to the most recent published information. However it has its own drawbacks. A certain chemical company had this to say:

“CMA is a dry formulation used as an ice melter on bridges, parking decks and airport runways. It does not attack rebar in reinforced concrete and is biodegradable, creating no problems in runoff water. It changes ice and snow into a oatmeal texture. This is not desirable for sidewalks, and it also may be cost-prohibitive, as it costs four to five times more than calcium chloride.”

The point is, as will all de-icers, they are designed to break up and loosen snow and ice so it can be mechanically removed. Instructions will typically say to remove excess de-icer, water, or slush. They are not designed to “burn-off” ice and snow.

If you follow the tips below you should not experience damage to your home’s concrete sidewalks and driveways.

• Never use de-icers on new concrete or concrete already showing signs of damage. Instead use sand for traction.
• If you must use a de-icer use calcium magnesium acetate (CMA) or another acetate product and follow the manufacturer’s instructions.
• CMA is rather expensive. If you need an economic solution you can use rock salt but remove it as soon as the ice can be loosened. However again, sand may provide a better solution.
• Never leave a de-icer on concrete to “burn off” the ice, snow, or water.
• Clean your drives and walks in the morning to allow the sun to help naturally de-ice the concrete.
• Never use a shovel or other metal tools to break up ice on concrete. This can cause mechanical damage to the surface.

We hope you winter is a safe one for you, your family and your home.

Should I replace my windows?

A very common question out there among home owners is how to determine if they need to replace their windows. Many times this question is driven by exposure to massive marketing campaigns aimed at energy efficiency. For example the 2009 stimulus package included a tax credit which at the time of writing expires December 31^st 2010 has prompted many recent advertisements on the subject.

One a side note, for windows to qualify for the energy tax credit they must have a 0.30 U-Factor. A U-factor is a measurement of the windows ability to prevent heat from escaping. The R value is the inverse of this measurement.  In short, the lower the U-factor the greater the R value which is the insulating ability of the window. One should consider that this measurement is based on the window assembly which is determined at the factory. It does not however include the installation of the window, which if poorly done, can eliminate any benefit of a low U-factor.

The campaign for energy efficiency may take the front seat in your process for determining if you want to replace your windows. This is expected when you consider the push by government agencies and window manufactures in this area. One nationally recognized window manufacture says their windows “can help you spend less to the utility company each month” and who wouldn’t like that. But let’s step back and look at where the push to replace your windows is coming from; home improvement stores, windows manufactures, home improvement contractors, and energy efficiency and weatherization companies.

Before you make a decision to replace your windows based on energy efficiency you must consider the product cost, the installation cost, and the window life cycle. In one study by Dr. William Hill, professor of Urban Planning at Ball State University, homes in the state of Indiana that were enrolled in its Energy Conservation Financial Assistance Program indicated replacement windows yield about an annual fuel savings of 1.4%.  However the average replacement cost was $3,350. Taking in account the life cycle of the windows, which can range from 10 years to 30 years depending on sources, the payback period for the windows is approximately 400 years. Based on energy efficiency alone replacement does not produce overall savings.

If energy efficiency is your main concern then upgrades to your building’s insulation and weatherization of your windows with storm windows or caulking will yield greater savings.

The choice to replace windows should be based solely on the following criteria:

• Windows are damaged and inoperative.
•  Personal taste.

The first may be avoided. Almost all wood windows can be repaired at a significantly lower cost than replacement. Vinyl and aluminum windows can also be repaired in varying degrees. If a contractor claims they cannot be repaired get a second opinion. The criterion of personal taste maybe satisfied by paint, stains, changing hardware, or different window treatments.

What I would like you to take away from this is the fact that energy efficiency rarely, if ever make sense as a decider for window replacement. Make sure you do your homework before choosing to tear out your existing windows.  

Extension Cord Safety

From Christmas lights to the family computer many of us use extension cords daily without a thought. They provide many conveniences around the home. However they can also be your worst nightmare when they are abused. Problem is that many of us do not know what this abuse is.

Over the years extension cords have resulted and many injuries and fatalities. It’s estimated that each year about 4,000 people are hurt by these modern amenities according to the US Consumer Product Safety Commission (CPSO). They have resulted in trip hazards, shocks, and fires. Many children have been seriously hurt or killed by placing the end of an extension cord in their mouth while it was plugged into an outlet. As a result the National Electrical Code (NEC) and voluntary industry safety standards like the Underwriters Laboratories (UL) have made changes to enhance extension cord safety.  You may have noticed these days your general use extension cords are made of heavier wire (#16 gauge wires) and have permanent safety enclosures over the female end of the cord.

Still human error cannot be removed. It is important to use extension cords properly, especially in older homes that have limited outlets. Some basic safety tips include; never using indoor cords outside, never using a cord longer than required, not overloading and cord, and reading the manufacturer’s instructions.

The Underwriters Laboratories (UL) has some of the following safety instructions:

• Look for the UL Mark on extension cords you purchase. The UL Mark means that representative samples of the cord have been tested for foreseeable safety hazards.
• Store all cords indoors when not in use. Outdoor conditions can deteriorate a cord over time.
• Never keep an extension cord plugged in when not in use. The cord will still conduct electricity until it is unplugged from the outlet.
• Make sure to use the covers for any of the cord’s outlets that are not being used. Children and pets face serious injury if they chew on unused outlets or stick sharp metal objects into the openings.
• Do not use extension cords that are cut or damaged. Touching even a single exposed strand of wire can give you an electric shock or burn.
• Never file or cut the plug blades or grounding pin of an extension cord or appliance to plug it into an old outlet.
• As a safety feature, extension cords and most appliances have polarized plugs (one blade wider than the other). These special plugs are designed to prevent electric shock by properly aligning circuit conductors. If a plug does not fit, have a qualified electrician install a new outlet.

If you follow recommended safety tips and common sense you can avoid costly damage to your home and the well being of your family and friends.

Where's the shut off valve??

Imagine this, you are enjoying an evening with the family watching your favorite television show when the unmistakable sound of running water interrupts your thoughts. Natural instinct maybe to run towards the source of the leak then panic as to how to stop the water. Most people seldom think about where their house shut off valve is. This is a very important thing to know and if you purchased a new home your professional Home Inspector should point out its location.

However knowing its location and being able to get to it are two different things. How many of us have the water shut off in the basement under steps, behind boxes, or even behind access panels that need tools to open. Get to know where the shut off is and keep the access clear. If you can have it moved, move it to a more convenient location. One anyone can get to that does not require crawling and ladders to gain access of.
Another thing to consider is the type of valve you have. Most homes will have a ball type valve or a gate type valve. Most older homes will have the latter. To tell the difference the ball valve will typical have a single handle that turns perpendicular to the pipe when its closed.  This is the preferred valve to have because of its ease of use. A gate valve will have a round handle that you turn; usually red or blue in color. This valve is harder to shut off quickly.

A last thought is that just like your body; valves need exercise. When a valve is never operated sediment and corrosion will freeze the valve in place. This is more common with gate type valves. You should operate your valve every 6 months to prevent this from happening. If you try to operate your house shut off valve and find it difficult to move with moderate force then have it replaced by a professional. Use this time to have it moved to a more accessible location if need be. Never force a valve! Also be forewarned that operating gate valves can loosen the packing nut (the nut located directly below the handle) and cause the valve to weep. This can be tightened using an adjustable wrench with light force.

If you ever have doubts or questions about your house shut off valve you can always consult with a professional plumber.