Ice Dam Prevention

Hey guys, first time poster here, been browsing the forums for a while now but hAvent joined in o. Any discussions yet.

I work In Massachusetts for an exterior remodeling company, up here we have to deal with a lot of ice dam complaints from customers who feel that because they just got a new roof, they should no longer have leaks from ice dams (I'm not quite sure that I can disagree with them in this regard.)

We always use grace ~6ft from the rake edge. Is this simply just a ventilation issue? Most roofs I inspect still have soffit and ridge vents, is that not enough up here?

Any knowledge I can gain with this would be helpful, I am one of the lesser experienced guys in the crew, only been roofing for 2 years now.

Thanks for any and all help.

Right on, Henry!

Do not hire a man who does your work only for money. Hire him who does it for the love of it. Henry Thoreau. B) :) :) B) Deep Down In Florida Where The Sun Shines Damn Near Every Day

lol with ya!

In this business we do get a chance from time to time to make some profound deductions, but one of the nicer things about our daily lives is the fairly high percentage of the time that we get served up such big fat, juicy, hardballs we can hit the damned things clean out of the park. (Like, for instance, how do you feel about wearing a full body harness on a six-foot eave, 4/12 pitch? Maybe those Guatemalans would be willing to comply with that. I know I never will. I'll be installing seat belts on my toilets first. Like they say, a two-foot drop is all it takes to kill you and porcelain can be very unforgiving.)

the only sure way to prevent ice dams is to remove the snow before it melts, even with proper venting snow is going to melt which isn't a problem till the temp drops below freezing again which isn't unusual at night. You don't even have to remove all the snow from your roof just the areas that need to be open to allow melt water to drain off rather then be trapped behind piles of snow and ice. Basically you need to keep an open channel for drainage, this includes gutters. No matter what you do the snow is going to melt, it's just a matter of where that melt water is going to go.

LOL Egg. I've been wanting to say something similar for 2 days now...... you did it for me... Thanks

If I wanted someone to build me an igloo, I'd look for an old-school eskimo. Probably not many of those left. On the other hand, if I needed help with things from the lower 48, like frost, hoarfrost, blizzards, white-outs, and ice dams, I'd definitely consult a Guatamalan. That kind of understanding would be second-nature to them.

MyOld..... "Ice Dam Prevention", begins with the architect/designer of a particular structure. In the case of of a re-roof, the roofer may, (and all too common), take on the role of an architect, or HVAC engineer/professional, by providing some type of ventilation system he/she simply came up with, via thumbnail/seat-of-the-pants, and in some cases, actual experiences, gathered throughout the years. On a single family rsidential re-roof, this method would most-likely work out just fine. Would I recommend attempting this on a 200 unit HOA project, that has potential, to come back & haunt me, with some frivolous or not lawsuit? Heck no, I'd refer, or work with an HVAC professional, so as to let them enjoy that liability exposure.

"Ice Dam Protection", is typically what roofers provide, by installing some type of band-aide approach, such as ice & water shield to prevent the resultant moisture from entering the structure, manifested by poor original design.

That seems to be the standard Nationwide. And of course the Manufacturers and suppliers are tripping over themselves to service them. Until they don't get paid.....

Yes Mike un cut at the peak is what I alluded to, along with insufficient air flow at the bottom.

I did live & work in Mass for 4 yrs. 1986-1990

God twill are you from Madsachusetts? You are describing this company that I am employed by to a T.

It's too bad too because all of the repair techs do really great work, but instead of having us do the full roof jobs they sub out to Guatemalans at anywhere between $60-$80 a square, and then send us back to the job to correct all of their mistakes (not flashing chimneys or side walls properly, not hand nailing caps) it's absolutely REDICULOUS.

If the ventilation is not suffienent to exhaust heat loss through the ceiling, resulting in snow-melt against the roof surface, which freezes when it gets to the overhang, you will get ice dams. Pure & Simple.

As twill alludes, seeing a ridge vent on a roof sure doesn't mean that anyone actually took the time to cut an exhaust at the peak. There are many, many miles of ridge vent with no openings under them. Soffit vents by themselves won't do anything except help reduce the temperature of the overhang, resulting in bigger, better and morer soffistikated soffits that are doing their part to fight global warming by building miniature glaciers throughout residential communities all across north america.

And here I thought I&W Shield was the answer to all sins.

As you are probably figuring out, you could put Grace, WinterGuard or anything else on 100% of the roof, 3 layers thick, and it won't make any difference.

Most residential "roofing" is about replacing the shingles and ignoring the roof system. It's cheaper and much, much, faster this way. Irregardless of what the manufacturer's SAY, they seem to endorse this method.

Replace the shingles, get onto the next job. Undelay! More sq's. = more dinero

Typical 'round here is UN Vented ridge vent. Putting UN Vented ridge vent in with lots of "Ice & Water Shield" will cure everything from bad breath to warts. I know, because the canvassers, OOPS, I mean Salespeople, have pronounced it, thus it so!

Wanna slow down the roof process, lower the amount of squares per man per day and piss everybody off?

Look in the attic and find sources of heat loss...

Unfortunetly, you are going to get all different answers and each one will be the right one and all the others will be the wrong ones. almost every person has a different theory about venting. good luck with this one.