Evaluating Attic Ventilation Is An Important Part of A New Jersey Home Inspection.
Improving attic ventilation:
We will be evaluating the existing attic venting in the home you are purchasing during New Jersey Home Inspections. Proper attic ventilation works together with attic insulation to help keep the home at comfortable temperatures in both the summer and the winter. In the summer months ventilation helps to dissipate heated attic air which can reach over 150 degrees. Proper ventilation can help to prolong the life of the roof covering because the temperatures in the attic remain cooler. In the winter the air flow through the attic helps to carry away humidity that can damage insulation, wood and ceilings.
Most attics rely on passive ventilation, a system of soffit vents at the eaves, gable vents at the sides and ridge vents at the top of the house. These types of vents create air currents in the attic space. Cool air enters through the lower vents and is able to escape through the upper attic venting (ridge vent). Active attic ventilation relies on powered ventilators which can be fans or an attic roof vents. A powered vent blows attic air out through a gable vent or through the roof top.
Assess attic ventilation:
To determine if your attic is adequately ventilated, you must first measure the square footage of the attic flooring. Then take the measurements of the existing vents. You must measure both the intake and the exhaust vents in the attic space. One rule of thumb method is that for each 300 square feet of attic space there must be at least one square foot of venting. In our area the ratio should be more like 1 to 150 because we have hot summers and variable winter temperatures. Often I find inadequate attic venting while performing New Jersey Home Inspections.
Improving soffit ventilation:
The simplest but least effective method to improve or establish soffit venting is to install soffit vent plugs. The soffit area is drilled out and a vent plugs are installed. Usually these plugs are three or four inches in diameter. The problem is that you need a lot of them. Another method is to install a rectangular louvered soffit. Openings are cut in the soffit areas and the vents are screwed in place. The best method is to install a continuous soffit vent. This requires a long rectangular opening that runs across the bottom of the soffits, then the long run of soffit vent is nailed or attached with screws. You should hire professionals to perform this type of soffit vent work because serious damage can be caused by improperly cutting the soffit areas.
Ridge vents should be installed by a roofing contractor. A ridge vent is installed at the very top or ridge of the home. This is accomplished by removing the existing ridge shingles to with in a foot of the gable ends. All felt paper must also be cut and removed.
A line on either side of the ridge is made, A circular saw is used to cut the roof sheathing along the line. The line set up will vary from manufacture to manufacturer. Remove all of the cut sections of the roof ridge.
The ridge vent is then installed over the roof peak per the ridge vent manufactures instructions. Roof ridge shingles are then installed over the venting to keep water out. The ridge vent will give a raised appearance to the roof ridge area of the home.
Powered ventilators (fans) mount in a gable end or in the roof itself. These units are usually equipped with a thermostat that turns the unit on when the attic temperatures reaches a certain point and shuts the fan off when the attic cools. Gable roof ventilators can often replace passive gable vents. Roof mounted ventilators require that you remove the shingles and make a hole in the roof. Most will be installed in between the rafters so they can remain intact.
One of the requirements of New Jersey Home Inspectors is to evaluate and report on the attic. I will be working hard to provide you with accurate and useful information about your attic space and roof venting.