Architectural Record – August 2019

114

CONTINUING EDUCATION

EDUCATIONAL-ADVERTISEMENT

E

very so often, a new way of building

homes emerges that is so simple, so

elegant, and yet so revolutionary that the

mind can hardly grasp it.

Take the case of a continuous perimeter

foundation vent system. This low-profile,

honeycomb crawl-space venting system is placed

between the concrete foundation wall and the

wooden sill plate to provide passive airf low

around and through the entire perimeter of the

home’s crawl space. This eliminates the need for

conventional vent boxes either in the concrete

foundation or cut into the rim joist.

“I’ll never go back to cutting vent holes

into rim joists and foundations,” says Takeshi

Kaneo of TK Home Design and Build in Bel-

levue, Washington, who has used the perimeter

venting system in two of his projects. “I wish I

had known it was available in the United States

sooner.”

Not only does this venting system provide

continuous and foolproof venting into and

out of the crawl space, but the thin ¾-inch

(20-millimeter) composite venting strips

provide a capillary break between the concrete

foundation wall and the wooden sill plate, elimi-

nating the need for a pressure-treated wooden

sill plate and preventing sill rot and sill break-

All images courtesy of Joto-Vent System USA, Inc.

Continuous Perimeter Foundation Vents

The next innovation in crawl-space ventilation

Sponsored by Joto-Vent System USA, Inc. | By Kathy Price-Robinson

CONTINUING EDUCATION

1 AIA LU/HSW

Learning Objectives

After reading this article, you should be able to:

1. Discuss moisture buildup in crawl spaces,
   the consequences of excess moisture, and
   how crawl-space ventilation protects the
   building and occupant health.


2. Compare conventional foundation vent
   systems, their effectiveness, long-term
   performance, and health impact.


3. Identify a new option/alternative for venting
   a foundation built over a crawl space.


4. Define continuous foundation ventilation
   systems and their sustainable benefits.


5. Describe several case studies of projects
   where continuous perimeter foundation
   vents were specified.

To receive AIA credit, you are required to

read the entire article and pass the test. Go

to ce.architecturalrecord.com for complete

text and to take the test for free.

AIA COURSE #K1908J

down from wicking moisture from the concrete

foundation. Additionally, as a treated sill plate is

not needed, neither is galvanized hardware.

The system has been used for more than

four decades in Japan and is the most common

crawl-space ventilation system used there.

INNOVATIVE DESIGN AND THE

KOBE EARTHQUAKE OF 1995

Prior to the Kobe Earthquake in 1995—which

measured 6.9 on the Richter scale, killed more

than 6,000 people, and destroyed more than

400,000 buildings—many crawl spaces were

vented in the conventional method using open-

ings in the foundation wall, while others used

the perimeter venting system. After the earth-

quake, some observers noted a difference in how

each type of building fared.

“After inspecting the devastation, we found

that homes using perimeter venting systems

survived for two main reasons,” says Takashige

Maebayashi, a Japanese-licensed architect and

director of engineering and development for

Joto USA. “The first reason is that the use of

the continuous venting system doesn’t require

cutting the foundation for crawl-space ventila-

tion. Houses that used the conventional style

methods naturally have weakened foundations

The latest innovation in crawl-space ventilation provides continuous airflow with no dead air pockets in the crawl space, eliminating the need for

unsightly and troublesome openings in the foundation wall or rim joist.