I Like To Exterior Services

What fails on a house, why it fails, and what it should cost

Home/Roofing/Turbine vents, no soffit intake

Roofing · Often DIY

Turbine vents but no intake at the soffit

Exhaust without intake pulls conditioned air out of the house instead of air through the attic. If the soffit vents are painted shut or blocked by insulation, the ventilation is not working, whatever is on the ridge.

More on 1940 to 1980 roofs
Quick answerTurbine vents on the roof only work if air can get into the attic low down, at the soffits. Exhaust without intake pulls conditioned air out of the house instead of air through the attic. Look up into the soffit. If the vents are painted shut or blocked by insulation, the ventilation is not working regardless of what is on the ridge. You can handle this one yourself. No call needed.

This is most common in homes built roughly 1940 to 1980. Spinning turbine vents were a popular add-on in this era. Many were installed without checking that the attic had any intake, and soffit vents that did exist were often painted over or buried in insulation later.

1Why it matters

  • Air has to come from somewhere. If it can’t come in at the soffits, the turbines pull it up from the house through ceiling gaps and light fixtures.
  • You pay to heat and cool it. That air is conditioned air leaving the house.
  • The attic stays hot or damp. Without a low-to-high flow, heat and moisture sit under the deck and shorten the life of the shingles.

2How to check it yourself

  1. Look up at the soffitsFrom the ground or a ladder, look for vents under the eaves. Note any that are painted over, screened with clogged mesh, or missing entirely.
  2. Look at the eaves from the atticWith a flashlight, look toward the outside walls. Daylight at the eaves is good. Insulation stuffed tight against the roof deck means the intake is blocked.
  3. Check on a sunny dayIf the turbines spin but the attic still feels very hot, the airflow isn’t working.
Attic and ladder safety

In the attic, step only on joists and wear a mask around insulation. On a ladder at the eaves, keep three points of contact and don’t lean it on the gutter.

3Fixing it

Do it yourself

  • Clear paint and debris from existing soffit vents
  • Pull insulation back from the eaves
  • Fit baffles so insulation can’t block the airflow again
  • Air-seal gaps in the ceiling below the attic

Leave to a pro

  • Cutting new soffit vents into solid soffits
  • Replacing rotted soffit or fascia
  • Changing the exhaust during a reroof

How much intake and exhaust an attic needs depends on its size. Check local code and the shingle manufacturer’s guidance before changing the vents on the roof.

4What drives the cost

Clearing vents and fitting baffles is mostly time and inexpensive materials. The cost climbs if solid soffits need new vents cut in, if soffit or fascia wood is rotted, or if the exhaust is being changed as part of a reroof.

Roofing cost

5Questions

Should I add more turbines?

Not until intake is fixed. More exhaust without intake pulls more conditioned air out of the house.

What are baffles?

Channels fitted between rafters at the eaves that keep insulation off the roof deck so air from the soffit can flow up into the attic.

Written by Jaylan Jones. I Like To Exterior Services earns a referral fee when a call connects to a contractor. See our business-model disclosure.