Attic Vents For Insulation

Grab a flashlight and inspect your attic during the winter.

Attic vents for insulation.

The recommended ventilation ratio to provide for vented attic assemblies when an air barrier is present is the 1 300 ratio as specified by most building codes. For the best results place roof ventilation near the roof s peak and soffit vents in the eaves. And in many of these cases the hip roof forms a large volumetric attic space to ventilate. Figure 7 mechanical ventilation used with a hip roof.

Of course there should be intake vents to ensure a balanced system. An attic with balanced ventilation has undereave or soffit vents which allow fresh air into the attic. Vents come in various styles. 1 300 ventilation ratio recommended.

To install the rafter vents staple them directly to the roof decking. Good roof ventilation can do this but shingle color sun exposure and insulation are exponentially more important to overall energy efficiency than ventilation. Covering up the soffit vents with loose fill or batts which can happen if you stuff insulation along the eaves is a huge no no. For the same reason insulation shouldn t touch the roof s underside.

These specialty vents do not affect the. At first it may seem odd to add insulation for warmth and then purposely allow cold air to enter the attic through vents but this combination is the key to a durable and energy efficient home. Rafter vents ensure the soffit vents are clear and there is a channel for outside air to move into the attic at the soffits and out through the gable or ridge vent. Insulation is used in an attic for cross ventilation to minimize potential for moisture accumulation and condensation to help energy savings and moisture control.

The fresh air flows up between rafters to the ridge where a ridge vent roof vents or gable vents allow the air to exit. Rafter vents or insulation baffles install in any rafter space to create narrow gaps that direct fresh air from the soffit vents to the peak of the roof. If insulation is allowed to bunch against the inside slope of the roof between the rafters air will be blocked before. One method is to use a powered attic vent with a humidistat thermostat located close to the ridge or top of the roof.

Rafter vents come in 4 foot lengths and 14 1 2 and 22 1 2 inch widths for different rafter spacings. If you see dampness or frost you need better roof ventilation and some attic vents. The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow. Sure installing roof vents for older homes can reduce your hot air during the summer but there are probably more low risk cost effective ways to increase your home s energy.

Air flows in through the soffit vents and out through the roof vents.