It may be the beginning of summer, but we can be sure that winter will come again.  If you plan well for your roof now, you will be prepared for the worst winters Utah can bring you.  That's why we need to be aware of the issue of ice dams in climates like Utah's while we install our roofs.  An Ice dam is formed when heat from inside a home or attic warms the roof and melts the snow on it.  This melted snow runs towards the cooler eaves and gutters, where it refreezes.  This process creates ice dams.  The result of these dams is water backing up under the roof shingles or behind fascia boards where it can cause damage to your home, both inside and out.  All shingle manufacturers exclude from warranty coverage leaks that are caused by water backing up behind these ice dams.   

The good news is, in most situations, ice dams are easily reduced if you take a few simple steps.  There are three ways to protect your home against ice dams: insulation, ventilation, and waterproofing shingle underlayment.  All three of these steps are vital to protecting your home.  Insulation minimizes heat loss from your home's living area, reducing the hot air which reaches your attic.  This is important to keep you warm throughout the winter, as well as to keep your roof cool.  Ventilation removes the heat from underneath your roof and helps to keep it evenly cool to prevent the freezing and thawing process.  Finally, waterproofing shingle underlayment can be installed on your roof before the shingles are applied.  This protects your roof in the case that an ice dam were to form.   

If you already have an existing roof without any major problems, you may still want to protect against ice dams.  You cannot install waterproof shingle underlayment on existing roofs without removing the shingles first or building a new addition.  However, it is possible to increase your insulation R-value, or level of thermal resistance, in your attic.  Also, it is typically simple to add ventilation to your attic at any time.   

Insulation is a great place to start when protecting your home from excessive ice dams.  If your home was built before 1980, you will most likely need to add more attic insulation.  The amount of insulation your house should have will vary on depending where you live, how your home was built and other factors, including your lifestyle.  In northern Utah, you should have a ceiling R-value of R-49, a wall R-value of R-19 and a floor R-value of R-25.  One inch of insulation can have an R-value of anything from 3.8-4.2, depending on the material.   

Ventilation is important to your home both in the winter and the summer.  Any heat that is lost from your home will be drawn out of your attic through your ventilation, keeping your roof deck cool.  In the winter, this prevents ice dams.  Attic ventilation can also allow any moisture from bathing, cooking and laundry to escape rather than sit and mold or rot your ceilings.  There are two common types of attic ventilation: a mechanical ventilation system and a natural ventilation system.  A power ventilator is an electric fan installed at the roof or gable that runs by a thermostat to ensure the roof is the proper temperature.  A natural ventilation system consists of simple vent or covered openings in your attic.  These are typically installed into your roof.   

If you are building a new home, or re-roofing your current home, it is essential to install waterproof shingle underlayment.  This underlayment is completely resistant to water and is an important step in defending your home against leaks and ice dams.  Shingle underlayment does not prevent ice dams, so it should be accompanied by taking the above steps.  However, installing an underlayment will prevent any backed up water from entering and damaging your home.  Shingle underlayment is installed differently for every situation, depending on the amount of snow and ice that will be on the roof, and the amount of attic space there is to allow air circulation (some underlayments don't breathe and can cause condensation when there is no air circulation - see previous blog on ventilation).  Generally, it is a good ideal to have it applied under flashing, at roof penetrations, areas where pitches change, in valleys, around chimneys, and along the eaves of the home.  You should consider building codes in your area when determining how much ice shield should be installed to prevent the ice at the eaves from backing up and coming in at your exterior walls.   

It is important to note that some situations call for a product called heat tape (sometimes called electrical heat coil).  Areas where this is most prevalent are at the bottom of valleys where it butts into a wall or chimney and does not flow freely off the roof.  This heat tape is effective in resolving ice damming issues, but is costly to operate.  It is best to consult with a roofing contractor when assessing areas that may require special consideration. 

Remember, proper planning can avoid a whole lot of pain later on when the roofing project or repair is completed!   Brady Roofing specializes is proper ventilation and waterproofing your roof for all climates.  If you would like a roof estimate, you can request a free estimate here. 

There are four main reasons that attic ventilation is important and can save you money:

1. The first is energy savings.  During warm summers, your attic could actually be heating your house, resulting in high, unnecessary energy costs coming out of your pocket.   
2. The second reason is the effect poor attic ventilation has on your roof's performance.  Under vented attics get very hot in most summer climates and can bake the shingle from the inside out.  
3. The third reason for installing the correct number and placement of vents is so moisture doesn’t get sucked in through some of the vents.  
4. The fourth reason is to reduce the probability of moisture build up in the attic from condensation.

The other day, I was inspecting a roof that had reported a leak.  While looking in their attic, I found an actual blanket of snow covering the floor of the attic.  This was the result of the attic being over ventilated at the ridge.  Because there were too many turtle vents on the roof, the attic actually started to intake air, and moisture along with it.  Snow was being pulled into their home during storms, causing obvious issues with moisture content.  This is the first time I had ever seen anything like this.  The problem could have easily been avoided if the roofing contractor had been more educated about attic ventilation principles.

Under ventilating your attic can be just as dangerous, and is much more common.  If your attic does not allow air flow, your attic would stay unnaturally warm throughout the winter.  This could cause snow on your roof to melt off and then refreeze in your gutters and at your eaves, which may force water to freeze up under your actual shingles.  In the summer, your attic could reach temperatures above 160 degrees, heating your home as you are trying to cool it.  The overwhelming heat of your attic could be prematurely aging your shingles or 'frying' them from the inside out.  Not only this, but if your attic gets hot enough, you could even warp the framing on your home.  

Proper ventilation is simple to enforce.  The biggest mistake I have seen homeowners make is to build a roof with proper ventilation and then install insulation covering the soffits (the area adjacent to the eaves where the air enters the attic through the soffit vents).  Another similar mistake is storing items that block the soffits.  This makes the ventilation system worthless.  Instead, be sure to install insulation clear of this area and store your items away from the vents to allow proper air flow.  

By far, the best way to ventilate your attic is to use soffit vents at the eaves and ridge vents.  These vents are installed by your roofing contractor.  Soffit vents are installed on the bottom of the overhanging area of your roof, or the eave.  These should be used to intake air, as they will not intake moisture along with it.  Your outtake vents should be your ridge vents at the peak or highest points of your roof.  These will help to cool your attic, and as they are covered with shingles, they will also avoid the intake of moisture.  This system will keep the air in your attic moving and flowing, maintaining the health of your home.  

How can you tell if you have proper ventilation in your attic?  One way to monitor this is by keeping track of the temperature in your attic.  An ideal temperature in the summer would be less than 20 degrees warmer than the outside temperature.  It is ideal to have the winter temperature the same inside as outside the attic, as to avoid ice dams.  The winter temperature is probably the most important to monitor in terms of up keeping your home and roof. 

Another way to measure ventilation is by a floor space to ridge ratio.  There should be 1 square foot of ventilation along your ridge for every 300 square feet of floor space in your attic.  For example, if you have 1200 square feet in your attic, you should have 4 square feet of ventilation along your ridge.  

Following these tips and precautions should save you money on your energy bill and in unnecessary repairs to your home.  Brady Roofing is very knowledgeable about attic ventilation and would be an asset to your home.  If you are interested in getting a free estimate, contact Brady Roofing here.