I am excited to introduce
this new colunm for the benefit of the neighborhood association readers. My
experiences stem from multiple careers starting in the early 1970's with
carpentry, to residential remodeling, to consulting with home owners in both construction
and home inspection process'. My hope is to make a contribution to home owners
which can be informative, with an eye on preventative maintenance.
I'm sure most homeowners
are with "Ice Damning", but how does it form and why has it been so
prolific this last winter?
Ice buildup on the eaves
of a building is generally caused by escaping heat from the interior exiting
the roof and melting snow and the freeze thaw cycles of cold nights and warmer
days. The resulting water flows over the unheated area past the exterior walls
and freezes. After these repeated freeze / thaw events, ice buildup traps water
and will not allow proper flow. Water then backs up under the layers of
shingles, re-freezes, expands in all directions and eventually can work under
all layers of roofing materials and drip to the interior. Ice infiltration does
occur every year, but we don’t see the results inside our homes very
often.
In winter ventilation of
the eaves, at the soffet and attic vents, high on the roof surface, keeps
colder air circulating under the roof plywood keeping the top layers cold.
Insulation above the exterior walls and in attic area will retain more heat in
the living space and less heat to melt the snow on the roof Another feature of
venting is to remove excess water vapor that can also freeze and cause damage.
In summer months ventilation can reduce the attic temperature from 60 degrees
above ambient temps to just IO to 15 degrees and can not only lengthen shingle
life, but can help maintain the integrity of structural members.
This year has been good
for ice damming, because of the early snow cover on roof tops and the constant
cold temps, together with a lack of attic insulation ... well we've had a
banner year as you all know.
"Next issue will
continue with unwanted moisture.
-
Michael Kehl
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May/June Table of Contents