Root of Roof Problem May Lie Underneath
Other Columnists
Q. With this winter being unusually cold, we've had a
problem with ice dams. We have a ranch with a low-pitched roof and a
front-porch overhang. The roof has soffit vents except for near the front-porch
overhang, as well as insulation in the attic and ventilation fans at each end.
We had a covered gutter system installed that keeps leaves and debris out but
allows water in. Ever since, we have more and more problems with icicles and
ice dams.
The icicles are coming out behind the fascia boards and from under the
shingles against the house under the front-porch overhang. In the 30 years
we've been living here, we've never seen anything like this. I am afraid of the
damage this is causing. What can we do to prevent this?
-Madeline Morris,
Setauket
A. I doubt your gutters are the problem. Ice forms on roofs because of
inadequate attic ventilation, inadequate attic insulation or both. Heat rises
through the interior of the house and attic, causing snow on the roof to melt.
As the melted snow runs down the roof toward the gutters, it freezes. That's
because the roof temperature near the eaves is colder than in the middle. As
melting snow refreezes, a dam is created and water backs up and seeps through
openings in the roof.
To eliminate ice dams, you'll need to restrict the amount of heat that
rises through the attic by adding another layer of insulation. The attic
temperature (I assume you have unfinished attic space) should be as close to
the outdoor temperature as possible. Check the R-value of your attic
insulation. This is the rating that measures the insulation's resistance to
heat flow. The higher the number, the better the resistance. On Long Island,
the recommended R-value for attic insulation is R38, although in colder areas
and upstate, it's R49. Perhaps adding another insulation layer is necessary. To
do this, fiberglass batts should be placed between the ceiling joists over
existing insulation. To determine the R-value, multiply 3.2 by the thickness of
the fiberglass insulation. To achieve R49, you need fiberglass insulation
about 16 inches thick.
Another step is to add soffit, fascia or roof vents or even ridge vents.
Your current insulation may be covering soffit vents, preventing proper air
flow. Painted vents or vinyl soffits installed against closed wood won't
provide air flow in the attic. If the vinyl was installed against closed wood,
remove the vinyl and drill 2-inch holes into the wood every foot or so. Then
reinstall the vinyl soffit. Cooler air should enter the attic from the lower
soffit vents, then force warm air through higher roof and gable vents.
Also, examine sources of heat loss within your home. Improperly vented
bathroom and kitchen fans or even heat ducts can cause warm air to collect in
the attic. These fans should be vented directly to the exterior of the home.
The venting situation might be difficult to evaluate and correct on your
own. Contact a reputable roofing contractor. An ice-shield barrier on the roof
might help. This involves removing shingles, placing a 3-foot-wide liner-type
material near the edge of the roof, then nailing shingles over the barrier.
Q. I will be relocating to Pennsylvania in the next six months. The builder
of my new home recommends a forced-air electric heat system, whereas others
suggest an oil-burning forced- air system. What's the best, least expensive
system for a 6,000-square-foot home? -Zeph F.,
Rockland County
A. I'm not familiar with utility rates in Pennsylvania, but what are the
odds that the cost of fossil fuels - oil, natural gas and propane - will go
down in our lifetime? The option of electric heat sounds better if you can
create your own electricity. I suggest using integrated photovoltaic roof tiles
as part of a solar electric package. In many areas, utility companies and
manufacturers of solar photovoltaic equipment offer rebates as high as 80
percent on new systems. Pennsylvania and New York have photovoltaic programs -
visit the U.S. Department of Energy's Web site, www.eere .energy.gov/state_
energy; click on the "State Specific Information" link. The Database of State
Incentives for Renewable Energy is another source - www. dsireusa.org. And for
those interested in Long Island's Solar Pioneer program, visit the LIPA Web
site at www.lipower .org, click on "Residential Customers."
As for heating equipment, I'd speak directly to the heating and cooling
contractor. In a 6,000- square-foot home, at the very least, you'll want a
two-zone system. Electric air-source heat pumps, used in moderate climates,
might be an option. These pumps use the difference between outdoor and indoor
air temperatures to cool and heat your home. Use an EnergyStar product with a
high SEER (Seasonal Energy Efficiency Rating). Visit www .energystar.gov.
Although he cannot always respond, Gary Dymski welcomes letters. Write to
him in care of Newsday Home Work, 235 Pinelawn Rd., Melville, NY 11747-4250 or
e-mail gary.dymski@newsday.com. Include your community of residence.
