Corey and Corey “The Roofers”
How Attic Gets Ventilated
It is your contractors/roofers job to make sure that your attic gets proper ventilation. Otherwise, there is no warranty on the shingles and you are risking your and your families health of getting mold developed in your attic, and then later in the entire house. For the ventilation to work properly, there are three very important components; intake of the air from the soffit/fascia areas, the exhaust of the air from the ridge, and properly insulated attic. If one of these components is missing, then it automatically means that your attic is not being ventilated properly.
The whole idea behind ventilation is to create the condition in the attic that the temperature in the attic gets as close as it is possible to the outside temperature. So that means that you need to allow as much air from the outside as it is possible to enter your attic. That usually gets done through soffits (circular vents, soffit vents, under-eaves vents etc), or through vented drip edge in which case an opening gets made on the upper eave between the fascia board (fascia - the board to which gutter gets attached to) and the roof decking (plywood, roof boards). Installing vented drip edge over the opening allows air to flow into the attic from the fascia board. These products are designed to allow airflow into your attic and most of the time they are hidden underneath the roof shingles so you cant even see them.
When you allow the air from the outside to enter your attic you need to make sure that the cold or hot air which gets generated by your house exits the attic. The best way is to use ridge vent on the peak /ridge of your roof. What we do we create ¾ -1” opening on both sides of the ridge cutting the roof boards/plywood on the very peak. Using the right kind of ridge vent that is externally baffled we create an air draft in the attic which pulls the air out of the attic constantly allowing outside air to enter your attic.
The important thing to remember is that when we ventilate the houses, we also inform you about the insulation in your attic if you need more of it or not. There is a huge misconception among the homeowners that a lot of insulation in the attic is good. That is simply not true. In fact, too much insulation can hurt your house. You are wondering how? Very simple way, it blocks the airflow in the attic. Most houses have either no ventilation or very poor ventilation which in some cases is almost the same thing. In order to fix poor ventilation in most cases when houses have soffit venting and right kind of ridge vent is to remove some of the insulation from the attic. It is the insulation that stops the proper airflow/air circulation in the attic. It is a very common problem when people hire energy companies to stabilize the energy flow in the house but what they end up with is more insulation and no ventilation, which down the road creates more problems for the homeowner. In order to guarantee the airflow besides the intake of air and exhaust. You need to make sure that in the attic there is enough space between the insulation and roof boards/plywood so that the air that is entering your attic can travel all the way up to the ridge/peak of the roof. Depending on what kind of house you have, you can resolve the issue of having insulation sitting too tight to the roof boards/plywood by installing ventilation baffles (proper vents, rafter mates etc). Ventilation baffles create a pathway between the insulation and roof boards/plywood so that the air entering your attic can travel all the way up to the peak/ridge.
What About Roof Fans, Gable Vents and Roof Vents? When I Have These, Does It Mean I Am All Set for Ventilation?
The answer is no, most likely you are not. Although you can have roof vents and fans to ventilate your attic, you need to understand that the amount of air coming through those vents is not enough. Based on our experience, we have never seen a single house that has roof fans, roof vents or gable vents that do not have ventilation issues. But here is the important thing, you can have those kinds of vents but when you are installing a new roof, the only way the Shingle manufacturer wants to ventilate your attic is with vented drip edge, soffit vents, and ridge vents. Anything else automatically voids the warranty on the shingles.