attic ventilation

guest-blogsheader image

Urban Rustic: Ventilation Baffles

Site-made ventilation chutes made from OSB look like a better bet than commercially available baffles

Posted on Nov 16 2017 by Eric Whetzel

Editor's note: This post is one of a series by Eric Whetzel about the design and construction of his house in Palatine, Illinois, a suburb of Chicago. The first blog in his series was called An Introduction to a New Passive House Project; a list of Eric's previous posts appears below. For more details, see Eric's blog, Kimchi & Kraut.

Tags: , , , ,

QA-spotlightheader image

How to Vent a Rainscreen

Should a rainscreen be integrated with soffit vents or vented only on the bottom?

Posted on Sep 18 2017 by Scott Gibson

A vented rainscreenConstruction detail appropriate for all but the driest climates to prevent moisture entry and to extend the life of siding and sheathing materials; most commonly produced by installing thin strapping to hold the siding away from the sheathing by a quarter-inch to three-quarters of an inch. — an air gap behind the siding — has become a standard detail in many new houses. It helps remove moisture that works its way through the siding, and in the process helps siding last longer. It's the "vented" part of this equation that has Gerald Pehl thinking.

"I've got an assembly design for a vented rainscreen, and it will be held continuous to the soffit spaces, which then vent through to the attic ridge vent via conventional vent chutes between the rafters," Pehl says in a comment posted in the Q&A forum at

Tags: , , ,

Image Credits:

  1. Fine Homebuilding

musingsheader image

Site-Built Ventilation Baffles for Roofs

If you want sturdy baffles that create deep ventilation channels, you’ll probably have to make your own

Posted on Apr 24 2015 by Martin Holladay

Roofs often require ventilation channels directly under the roof sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. — either for a short section of the roof (for example, near the eaves) or for the entire roof, from soffit to ridge. When the wind is blowing, these ventilation channels allow air to move from the soffit vents to the ridge vents.

Tags: , , , , , ,

Image Credits:

  1. Image #1: Fine Homebuilding
  2. Image #2:
  3. Image #3: CurbDog on
  4. Image #4: William Rose

musingsheader image

All About Attic Venting

We vent attics for four reasons, and all four goals can be better achieved by adopting measures other than attic venting

Posted on Dec 6 2013 by Martin Holladay

Most homeowners and builders believe that attics should be vented. If you walk down to your local lumberyard and lean on the counter, the employees and nearby customers will offer a variety of opinions about why attics need to be vented. Unfortunately, it’s highly unlikely that the statements you hear will be true.

Tags: , , , , , ,

Image Credits:

  1. Fine Homebuilding
  2. Morrison Hershfield

building-scienceheader image

Insulated Rooflines and Shingle Temperatures

Research from Florida shows that shingles don't get much hotter with spray foam insulation under the roof sheathing

Posted on Jul 3 2013 by Allison A. Bailes III, PhD

One of the most common questions I get when I describe homes with insulated rooflines is, "What does that do to the shingles?" Some roofing companies have made noise about this topic, saying that if the shingles can't conduct heat downward into the attic, the shingle lifetime will be greatly reduced.

Tags: , , ,

Image Credits:

  1. akeg, from
  2. FSEC

QA-spotlightheader image

Pondering an Attic Conversion

Adding spray foam to the underside of the roof sheathing will turn a vented attic into a conditioned space — but will it also create problems?

Posted on May 20 2013 by Scott Gibson

Rob Graff is getting a new roof, and with it an opportunity to turn his vented attic into an insulated, conditioned spaceInsulated, air-sealed part of a building that is actively heated and/or cooled for occupant comfort. .

But he’s also got some concerns.

Tags: , , , , , , , , , ,

Image Credits:

  1. Fine Homebuilding

building-scienceheader image

Don't Try This At Home: Armchair Building Science

Is the mold on the plywood in this attic the result of inadequate attic ventilation or air leakage?

Posted on Apr 2 2009 by Peter Yost

The homeowners called me after a certified home inspector stated that the attic was underventilated and moisture was building up as a result. The roof assembly had soffit vents at the eaves and two gable-end vents. These vents would not be as effective as ridge-to-soffit ventilation, but were probably close to building code requirements (see Green Basics – Attics).

Tags: , , , , , , , , , , , , ,

Image Credits:

  1. Rick Roberts

Register for a free account and join the conversation

Get a free account and join the conversation!
Become a GBA PRO!

Syndicate content