On Jan 4, 6:53*am, wrote:
On Thu, 3 Jan 2013 20:09:02 -0700, "WW"
wrote:



wrote in messagenews:uucbe812s14r4ugohhifgirf4h25s44428@4ax .com...

When I was young, I remember my parents house always had problems with
ice dams in the winter. The roof was asphalt shingles, and had no
overhang, except for a rain gutter. *I remember several times water
would start to drip inside the house, and then my father and me would be
up on a ladder pouring boiling water on them to break them up, while mom
was having a panic attack in the house. *Eventually he bought some
electric coils that helped, but were not a complete solution.

The "complete solution" to ice dams is proper insulation and
ventilation. The idea is to keep the roof the same temperature as the
air. "Ice shield" is in insurance.

I've known this to be a problem for other people too, although the
houses that have a decent overhang (at least one foot), seem to have
less problems with this.

These days, more roofs are being covered with steel roofing, rather than
shingles. *I've used it on unheated barns and sheds, but not on a house.
I'm wondering if ice dams are as much of a problem on steel roofs?
Obviously, there are still joints between the sheets of steel, and water
could get in at those joints. *Yet, the steel is more slippery and
ice/snow tends to fall off more than on asphalt shingles.

"Standing seam" roofing has ridges on/between the seams. *It would
take a hell of an ice dam to breach the seam. *Again, the real
solution is to keep the roof deck the same temperature as the outside
air. *This is even easier with a metal roof.

I'll mention that on my barn, several years ago, I did get a buildup of
snow, then some warm weather caused the upper portion of the snow to
melt, and an ice dam did occur at the lower edge. *The nice thing about
the steel roof, in a barn with no ceiling below it, is that I just took
a 2x4 and banged the underside of the steel, and the chunks of ice broke
apart. *Then a long pole was used to pull them down.

Was it leaking between horizontal seams or vertical? *It shouldn't
have leaked at all, but my guess is that your barn is quite a bit
warmer than the outside air.

One other thing I should mention in this regard, is that a local
business had a large steel roof, which was above a parking lot. *Several
years ago, there was a warm spell during the winter, and a huge block of
ice and snow fell, and actually destroyed a few cars parked below,
(including the car belonging to the owner of the building).

That's not uncommon. *In Vermont, there were signs advising people
that " parking here" was dangerous. *In some places they put up
barricades where ice was known to fall.

This indicates that the steel roofs have problems of their own, but I
wonder if the ice dams are less of a problem on a heated home?

Properly insulated, there should be no problems with ice.

I've also seen that they sell these plastic things that attach to the
steel roofs that are supposed to keep the ice from falling. *I'm not
sure if that's a good idea or not. *Plus those things look flimsy....

It probably is a good idea above your porch/sidewalk. *Your insurance
company might appreciate them. *;-) *OTOH, you've admitted that you
know it's a problem. *:-(

I'm looking for opinions based on what others have experienced. *I'd
much prefer to use a steel roof when I build my small house. *It costs
more, but has a much longer life span, and is more durable, not to
mention is much easier to install than shingles.

It's harder to install right. *A monkey can (and usually does) install
shingles.

Lived in Colorado mountains for 13 years. High altitude (10000) feet.
Average snowfall at 300 inches a year. House had shingled roof. Problem with
ice dams and leaks from them. No gutters were used in that area because of
freeze up. I stripped the roofing off and left the tar paper. House was 40
feet long and A frame type roof. Front required 16 foot pieces and rear
required 20 foot pieces. This was a five twelve pitch. Installed steel Pro
Panel type. This solved the leaks. When the snow built up to 2 or 3 feet, I
used a T setup (10 feet of *1/2 inch metal conduit and a 3 foot 2 x 4...I
would reach up and pull off snow about 2 or 3 feet of the edge snow. It
would come off easy. In a day or 2 the rest would slide to the edge and I
would repeat the removal again. Never had a snow slide because temps *would
be below zero most nights. Did the entire job in 3 days. *WW

Sounds like your insulation/ventilation wasn't up to snuff.

is correct, nearly all ice dam problems are
insulation/ventilation issues.
Keep the roof uniformly cold and you'll seldom get ice dams.

The real killer is a cold over hang area & an "upstream" roof area
that "leaks" heat from the house / attic.

Cutesy architectural features are a problem as well.