zeb Posted March 14, 2007 Report Share Posted March 14, 2007 I received a call today from a lady that was complaining about here contractor. She stated that she has been having problems with ice build up on her roof and thinks her contractor may have not insulated enough. She wants to hire me and I feel that this may be a hot potatoe that will only get me a seat in a courthouse and a small witness fee when it goes to court. OPINIONS PLEASE! Quote Link to comment Share on other sites More sharing options...
hausdok Posted March 14, 2007 Report Share Posted March 14, 2007 Hi, If she's got ice-damming at the eaves and her house is insulated to current accepted specs for your area, it isn't the insulation that's the problem, it's the air passages into the attic and possibly blocked ventilation. That attic should have a temperature difference of only about 3° from outside. The best insulation won't stop air passages, it will only keep the home warm inside. If you understand the building science involved with vapor diffusion and attic ventilation, you'll be able to help her. However, if you're not really, really comfortable with it, stay away from it or you could end up getting your p** P** wacked, so to speak. There's a pretty hotly-debated thread about this going on right now at my building science forum over at the Journal of Light Construction Online. Stop on by and see what the guys are talking about. Martin Holladay just schooled one or two of them about air passages and you can find lots of previous discussions on the same topic in the archives there. http://www.JLCOnline.com ONE TEAM - ONE FIGHT!!! Mike Quote Link to comment Share on other sites More sharing options...
Steven Hockstein Posted March 14, 2007 Report Share Posted March 14, 2007 Many questions come to mind... How old is the house? What was the contractor hired to do? Does the town require an insulation inspection as part of the building process? Are there leaks because of the ice? I agree with Mike. If you are not a qualified expert about what are the causes, their expert and attorney will rip you a new one. If you can confidently be her expert and want to be properly compensated, have her sign a retainer agreement with a schedule of fees for your time. They can't make you be a witness for a "Small witness fee" if you are her expert. Quote Link to comment Share on other sites More sharing options...
ozofprev Posted March 14, 2007 Report Share Posted March 14, 2007 And where is the ice? We are ASSuming it to be at the eaves. Originally posted by Steven Hockstein Many questions come to mind... How old is the house? What was the contractor hired to do? Does the town require an insulation inspection as part of the building process? Are there leaks because of the ice? Quote Link to comment Share on other sites More sharing options...
zeb Posted March 15, 2007 Author Report Share Posted March 15, 2007 The house is 1 year old. No regs because it is out of the city. Yes it is at the eaves. The contractor built the house. Quote Link to comment Share on other sites More sharing options...
hausdok Posted March 15, 2007 Report Share Posted March 15, 2007 So, There's your answer. When you go in that attic, you're going to find a lot of air passages through ceiling fixtures, wiring that's passing up through the framing, at top plates, etc. That warm moist air is warming the roof enough to thaw the field. The water runs down over the eaves where the overhang is cold and it freezes and builds up a dam that causes water to back up on the surface. Fix the air passages, seal every light switch and receptacle and ensure there's good airflow up the underside of the roof and you aren't using gable vents in combination with ridge vents or jacks at the ridge and eave/soffit vents, and it'll probably be fine. OT - OF!!! M. Quote Link to comment Share on other sites More sharing options...
Neal Lewis Posted March 15, 2007 Report Share Posted March 15, 2007 What if you have a warm air furnace in the attic. The furnace itself is giving off some heat and the ducts give off some heat, since the ducts are insulated to R4.2 or R6.0, at best. I'm thinking that it must be impossible to stop ice damming completely. Of course,that's where the ice shield and electric ice melting cable come into play. Quote Link to comment Share on other sites More sharing options...
ozofprev Posted March 15, 2007 Report Share Posted March 15, 2007 Hi Neal, I spent 3 years of high school in East Brunswick and have lived in Rochester/Buffalo for many years. I'm not doubting you, but I have never seen a furnace anywhere but the basement (or 1st floor if no basement - rare) in this part of the country. Do you really see that? I can't see it as anything but, well, dumb - and for the reasons you state. Originally posted by Neal Lewis What if you have a warm air furnace in the attic. The furnace itself is giving off some heat and the ducts give off some heat, since the ducts are insulated to R4.2 or R6.0, at best. I'm thinking that it must be impossible to stop ice damming completely. Of course,that's where the ice shield and electric ice melting cable come into play. Quote Link to comment Share on other sites More sharing options...
hausdok Posted March 15, 2007 Report Share Posted March 15, 2007 Hi Neal, I agree with you. That's a hard one. In that case, you have to live with the ice dams. It's not impossible. One would have to bring the furnace into the conditioned envelope of the house, by building an insulated enclosure around it or insulating the underside of the roof. It's pretty hard to insulate the underside of the roof well enough to prevent air passages, unless you densepack it with cells or foam the entire underside of the roof. Then it has to be a category IV furnace with a sealed combustion chamber that's getting it's air from outside or you have to ventilate that area. If you have to ventilate that area and still want to prevent ice dams with less than a Cat IV, you'd need to insulate the underside of the roof and the ceilings. It's not cost effective. That's why installing a furnace in an attic in a cold climate doesn't make sense. Do they actually do that in New Jersey?! It gets pretty cold there. I'd expect anyone doing that in New Jersey to be a pretty heavy drinker. OT - OF!!! M. Quote Link to comment Share on other sites More sharing options...
Neal Lewis Posted March 15, 2007 Report Share Posted March 15, 2007 Gary, it's common in newer houses over 3,000 square feet to put the second furnace/air con unit in the attic. If the contractor is smart, he will put the Cat IV furnace in the basement and the regular 80% unit in the attic. Dealing with freezing condensate is more of a problem than ice damming. Quote Link to comment Share on other sites More sharing options...
Kyle Kubs Posted March 15, 2007 Report Share Posted March 15, 2007 Originally posted by hausdok Hi Neal, That's why installing a furnace in an attic in a cold climate doesn't make sense. Do they actually do that in New Jersey?! It gets pretty cold there. I'd expect anyone doing that in New Jersey to be a pretty heavy drinker. OT - OF!!! M. Oh yes, I see it quite a bit actually. mostly in newer homes (McMansions with two or more forced air zones, Townhomes, the latest trend of adding an entire house onto a small older house...) One of the townhome developments here has all the furnace/air handlers in the attic even thought it is only one zone and there is a basement. For the record, I agree, it's a stupid thing to do. Welcome to the world of... "I don't care how long it lasts! We need four hundred units completed in three months so we have gains to show our stockholders!" If they put an induced draft gas furnace in the attic they just run a metal B vent four feet through the roof right there and they don't need to build a chimney. Quote Link to comment Share on other sites More sharing options...
ozofprev Posted March 15, 2007 Report Share Posted March 15, 2007 Thanks Neal, Buffalo is mostly old. They were smart enough NOT to do that in 1900. Maybe I'll see one this year. Anything special about it? Attic ventilation is dual purpose in that case. Anything else? Originally posted by Neal Lewis Gary, it's common in newer houses over 3,000 square feet to put the second furnace/air con unit in the attic. If the contractor is smart, he will put the Cat IV furnace in the basement and the regular 80% unit in the attic. Dealing with freezing condensate is more of a problem than ice damming. Quote Link to comment Share on other sites More sharing options...
hausdok Posted March 15, 2007 Report Share Posted March 15, 2007 Huh? I'm shaking my head. Guess it's not such a bad idea though. That way, when home inspectors get called out to diagnose what's going on, because the homeowner's roof leaks due to ice damming, and the builder insists its fine, they can make lots of extra dinero as expert witnesses in court. I've got the motto: Attic Furnaces are Gold! ONE TEAM - ONE FIGHT!!! Mike Quote Link to comment Share on other sites More sharing options...
zeb Posted March 16, 2007 Author Report Share Posted March 16, 2007 such a common thing causes many problems Quote Link to comment Share on other sites More sharing options...
emalernee Posted March 16, 2007 Report Share Posted March 16, 2007 See the attic units all the time in the big houses here in Northeast Ohio. Most are 90+, but some 80+ are seen. We use lots of soffit and ridge vents with baffles at the eves to keep the 12+ inches of insulation from blocking the airflow. Problem I see here is bad detail. Bath fan vents not properly run and discharged, allowing water to lay in the vents and leak through the ceilings. Also, furnaces out of sight, out of mind. Most of the time I fine filters that haven't been cleaned or changed because homeowner didn't know they had a unit up there. The dumbing down of America starts in the home. Ezra Malernee Canton, Ohio Quote Link to comment Share on other sites More sharing options...
Darren Posted March 16, 2007 Report Share Posted March 16, 2007 As Neal says, attic units are the norm around here. Just Wed I did a renovation with a crawlspace; unit in the attic, temp difference between 2nd & 1st floor was about 12 degrees; very tough to balance. Other problems are no walkway or platforms to/at units; single wall vents; air leakage all over the place; flex duct in contact with vent and of course my favorite, the filter is either too big or the slot is not sealed and you're pulling attic air into the system. Darren www.aboutthehouseinspections.com Quote Link to comment Share on other sites More sharing options...
ozofprev Posted March 16, 2007 Report Share Posted March 16, 2007 Thanks Darren. Still, seems dumb. Quote Link to comment Share on other sites More sharing options...
kurt Posted March 16, 2007 Report Share Posted March 16, 2007 With square footage being the premium that everyone seems to want, things like equipment are getting jammed everywhere they shouldn't be. I see furnaces in attics all the time. On top of the stuff already said, supplying heat from ceiling registers finishes it off. Really dumb, and really common. Quote Link to comment Share on other sites More sharing options...
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