Roof and Attic Ventilation

Although there are many ventilation products, the purpose is the same. To get hot air out of your attic. However, it’s not only to save you money on your electricity bills like you may be thinking. Actually, the main reason to ventilate is because it makes your roof last longer. Think of it this way. The hot air trapped inside your attic is literally cooking your roof from the inside out. This damages the underlayment (that important layer you can’t see) and the shingles. The shingles will actually begin to crack (thermal expansion) and the granules (small rocks on the shingles) will loosen and fall off the roof.

As this happens, the shingles begin to deteriorate faster than normal and soon, they could even start leaking. The hot air also causes paint to bubble up. Plus, in the winter time the trapped attic air becomes warm and moist. The moisture soaks into the insulation, which in turn reduces its effectiveness. It can also soak into your sheetrock below the insulation (your ceiling) and cause staining and rot.

Remember – Ventilation….Good. Non-ventilation…Bad.

Problems caused by poor ventilation:

1. Your roof has a shortened life-span.

2. You have to paint your house more frequently.

3. Your insulation can lose effectiveness.

4. Your sheetrock may become damaged.

5. Your electricity bills may be higher.

Ok, so now you may be thinking, “I understand why I need ventilation, JUST TELL ME HOW TO DO IT!”

Just like you breathe in and breathe out, your roof does too. Your roof system needs intake and exhaust venting (or ventilation) to perform properly. Intake lets the air in. This is done with soffit vents (or eave vents). Next time you are outside your home look at the roof overhangs. You should see some metal grills (almost like air conditioner vents in your home) every 8’ or so. If you don’t have them you need them.

Exhaust ventilation lets the air out.

There are two categories of exhaust vents:

1. Passive, meaning no moving parts. They are just holes in the roof with a cap over the top.Passive vents include low-profile vents, dome vents, and ridge vents.

2. Active, meaning there are moving parts. They pull hot air out of the attic. Active vents include turbine vents, power vents, and solar power vents.

Passive vents don’t have moving parts that break, squeak or cost you money to operate. They are also generally less expensive to install. However, as with any type of venting, since hot air naturally rises to the top of your roof, there are pockets of trapped hot air which can cause the problems described above. Ridge venting was created to solve that problem. Ridge vents are installed on the highest points of your roof and thus eliminates those hot air pockets. Research has shown that 32’ of ridge venting is equivalent to 5 turbine vents.

Active vents draw hot air out the attic by using a turbine or motorized fan. The downside here is that those moving parts eventually wear out. Thermostats will break and motors burn out. The typical turbine vent lasts 5-7 years and power vent lasts 3-5 years. Another downside with the power vent is paying an electrician to hook it up and then paying to operate it every month. One of the newer advances in roofing ventilation technology is the solar power vent. You get the many of the same the advantages of an electrical power vent but there are no electrical hook-up charges or ongoing electricity costs.

Unfortunately, there is not a “One-Vent-Fits-All-Roofs” that we can sell you. The best way to know what ventilation you need is for you to call us for a Free Ventilation Analysis.

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