Ron Williams
I will be the one who comes to your house.





                                      

 

 

 

 

Attic Ventilation

 

 

Every area of your home is effected by attic moisture, heat, and air flow.

Houses are built much "tighter" today than they were 20 or 30 years ago.

 Windows are more efficient, house wraps are now commonly used, the R value of insulation has increased, overall, our homes are more weather-tight. In doing this we trap the moisture in the home. Indoor moisture is generated by many things. The normal perspiration and breathing of a family of four adds about ½ pint of water to the air every hour. Cooking three meals a day adds four or five pints of water to the air. Each shower contributes ½ pint. In fact, every activity that uses water, (like dishwashing, mopping floors, doing laundry) adds moisture to the air. Experts say that the daily living activities of a family of four can add more than 18 gallons of water a week into the air of a home. Air moisture will flow toward drier air to equalize itself. This equalization process actually forces the indoor moisture through the ceiling and insulation into the attic area.

Ventilation of your attic is important for two reasons. During the summer, excess heat that builds up in the attic during the day results in high energy costs for cooling, or uncomfortable living conditions.

 Also, moisture produced within the home may move into the attic if ceiling vapor barriers are not used, and they usually aren’t. If this moisture is not exhausted from the attic it will condense and cause insulation and construction materials to deteriorate, or cause mold or mildew to develop.

So, temperature and moisture control are the main reasons for proper attic ventilation.

 

How much attic ventilation is enough?  The most ventilation is required to remove heat in the summer months. Winter attic ventilation must be enough to remove moisture vapor moving from the living space to the attic. In general, ventilation adequate for summer cooling is more than adequate for winter ventilation. Studies indicate that further increases in ventilation are not effective in significantly reducing attic temperatures.

If the ceiling is poorly insulated, you may need a little extra ventilation. Attic ventilation can be accomplished by gravity ventilators, wind assisted ventilators or power ventilator. Regardless of the method used, the purpose is to provide uniform ventilation of the attic for proper temperature and moisture control. Natural ventilation is the most common and energy-efficient method of achieving attic temperature and moisture control. It is also the most inexpensive, and my personal preference. If a space has high air outlets in conjunction with low inlets ,ventilation occurs as the air within the space is heated.

 

At Roof Doctor, we accomplish this with the use of eyebrow vents, installed at optimum locations.

If you would like a free evaluation and quote for upgrading your attic ventilation, you can submit a quick online request at: http://www.roofdoctor1.com/form1.html,

or give us a ring at (800) 409 – 4910.

 

The Benefits of Roof Ventilation

• Allows outside air to flow naturally upward and out of attic.
• Promotes a cooler, drier attic.
• Helps prevent moisture from becoming trapped in insulation, structural wood, shingles and roof deck.
• Helps prevent rotting, mildew, drywall damage, peeling paint and warped siding.
• Provides year-round performance for consistent ventilation without energy consumption.

For a balanced ventilation system, you should have 50% of your NFV (net free ventilation) at the upper third of the roof and 50% at the lower third.

 Balancing ventilation in this manner allows for air intake to occur at the low points and exhaust to take place at high points. Air movement from low to high points is aided by natural convection.

In attics which are not properly vented, moisture is also created by simple condensation. The air inside an improperly vented attic will be warmer than the air outside. When this warmer, moist air comes in contact with the colder roof sheathing condensation will occur. In effect, it can actually "rain" in your attic.

The vent picture on the right, is known as an "eyebrow vent". It is a low profile, hard galvanized steel vent, with a substantial flange that differs in size depending on what type of roof it is to be installed on.

Use of the Eyebrow vent is a very practical and effective way to ventilate your attic. Eyebrow vents are installed on your roof, and can be used as attic intake vents, as well as attic exhaust vents.

 

 

Contact Roof Doctor for Roof Repair, Roof Inspection, Roof Certification and New Roofs.

Call today Toll Free at 1-800-409-4910 or CLICK HERE to order an inspection from a licensed, bonded and insured roofing contractor. For all your roof and deck repair, inspection and power washing needs, Call the Roof Doctor -  You'll be glad you did!

Ron Williams, Sacramento Roof Doctor