Ventilation Fan Sources
I love your magazine and the tremendous information in each
I live 100 miles from Richmond, Va., on the Chesapeake Bay. My
company does a number of crawlspace renovations as well as new
foundations. Can you recommend a supplier for the "continuous-duty
low-sone fan" that you show in your article ("Sealing Crawlspaces
in Flood Zones") on page 19 of the May/June 2006 issue? My HVAC sub
has had no luck tracking one down.
Editor's note: Several manufacturers offer
quiet fans rated for continuous duty. Fantech (http://www.fantech.net) makes a number of inline duct
fans that would work, including the 122-cfm FR Series fan,
featuring a lightweight plastic housing. These can be mounted in
exterior or wet locations, allowing for some creative placement
that can ensure absolute quiet. Panasonic's Whisper Line models
(http://www.panasonic.com) are also excellent
Online sources for these models include Westside Electrical
& Lighting (http://www.westsidewholesale.com) and Energy
I read your article on sealing crawlspaces in flood zones
(Soundings, May/June 2006) and found it to be very good, although
you may want to consider adding another detail to the job:
Adding batt fiberglass insulation to the rim joist is one way to
seal above the foundation. But fiberglass insulation is not an air
barrier, and therefore does not effectively seal the crawlspace
from heat loss and moisture infiltration. So before adding the batt
insulation, I would recommend caulking or air-sealing the rim joist
and sill plate with one-part foam. Then add 1-inch foil-faced rigid
insulation over the batt, and seal around the rigid insulation.
Although this may be time consuming, it will help prevent moisture
infiltration and, better yet, prevent excessive heat loss from the
Another method you might want to consider would be to seal the sill
and band joist with two-part foam. Although this may be a little
more expensive, it would be faster and less labor intensive.
Energy Master & Environmental Solutions
Good article on mold remediation ("Genuine Mold," May/June 2006).
However, I did detect one item that goes against current wisdom.
Post-remediation testing should be conducted by a third party, not
by the mold remediation company.
Barbara L. Lee
In the article "Low Country Rx: Wet Floodproofing" (July/August
2006), we overlooked inclusion of structural sheathing over the
steel studs in one of the cavity-wall assemblies (Figure 3, page
40). The corrected illustration and original caption are shown at
Shown here are two options for drainable and dryable cavity-wall
assemblies suggested by building scientist Joseph Lstiburek. The
wall designs share several key characteristics: (1) No
water-sensitive materials are used; (2) exterior cavities are
vented to the exterior; (3) interior cavities can be opened to
allow passive air-drying in the event of a flood by removing strips
of wall material at top and bottom to encourage convective