Replies

1. 
   MarkJ_from_Pa | Nov 08, 1999 04:52am | #1

   *
   Thanks Fred; Still researching this problem, I have done a lot of weatherization projects over the past 20 years, but as the majority of homes in this area have basements, I have just never encountered this type of situation. As I said I'm still researching this, I know this isn't the only house with heat in the attic, so there has to be a solution. Mark

1. 
   jjmcgough | Nov 08, 1999 06:11am | #2

   *Mark,If you can't cure the ice damming by sealing and adequately insulating the ductwork, stopping the exfiltration of heated air from the living space.Try roof and gutter melt. Orbit Mfg. reps Kabel Alctel here in the US.I know this is a bandaid but I have been involved with a contractor locally who has eliminated the water damage of piss poor construction methods via this fix. Many commercial projects (especially a couple I have seen) can be a nightmare to correct, especially this close to winter. And Fred is right, the insurance company will only want to pay for ice damage once. The next time, the last one who laid hands on it or took the remedial action will be writing the check. Of course you could recommend the above strategy to limit the damages for this season until a wiser solution can be employed next summer? Just get it in writing, ironclad.

1. 
   Joe_Fusco_ | Nov 08, 1999 06:31am | #3

   * MarkJ,

   It seems like someone put the heat right where you don't what it, next to the roof. Without knowing all that would be needed to be known. . . I would venture a guess that if you enclose the unit and insulated around it you could beat the ice damn problem. That being said, here are some things to think about. . .

   In this situation I would want to make sure that the venting system is working. You didn't mention the fuel supply for the unit, a good guess might be gas. By having a working venting system you can supply fresh outside air to the furnace unit without adding another hole in the roof. This will also prevent the unit from taking fresh air from the living space. A wall vent installed in the enclosure will supply the intake and the present flue the exhaust. This is all based on the fact that there is not an "independent" air intake now. If there is, no vent would be needed.

   Air sealing the attic floor and adding at least another 6"-8"'s of fiberglass to the attic floor is also imperative for this to work well. It's important that no warm air find it's way back into the attic to in effect, create the same condition.

   In no way is any part of my reply to be taken for granted, only you can make the call as to what can and can not be done there. As always, as much information as you could supply will always be very helpful in getting a better understanding of the problem.

   Joseph Fusco View Image

1. 
   mark_J | Nov 09, 1999 07:53am | #4

   *I can see that I did not describe this situation clearly in my first posting, let me do so now. The furnace is an 80% efficient gas unit. Combustion air is supplied from the attic, and vented through a stack in the roof. There is no added insulation around the unit, nor is there any insulation above the unit. The house is 24' wide with standard 4/12 trusses on the section where the furnace is at, overall sq. footage appx. 3000. So, I have a fairly large furnace in a fairly small space. The eaves which are vented, but not baffled, are blocked in most bays. I hope this paints a little clearer picture. As to what I found to date, since combustion air is provided from the attic, I must use passive ventilation with insulation to remove excess heat in the attic. I am considering, in addition to baffles at eaves, and insulation on attic floor, attaching duct board to the bottom of the truss top chord above the furnace. Depending on what measures the client wants to take to ensure that this problem is solved, I could take other steps. Such as wraping the furnace in duct board, without restricting combustion air. Also, I could run baffles and FG from eave to ridge, with duct board above furnace. The last steps may be overkill but I would like to do this right the first time. All opinions appreciated. Thanks; Mark J from N.W. Pa.

1. 
   Joe_Fusco_ | Nov 10, 1999 03:59am | #5

   * MarkJ,

   Your first post was clear, to me at least. You can't solve the ice damn problem caused by this furnace without enclosing it or getting it out of the attic all together.

   Joseph Fusco View Image

2. 
   Bill_Conner | Nov 12, 1999 09:18pm | #6

   *ParPak?

3. 
   Dan_Morrison | Nov 17, 1999 10:46am | #7

   *Bill,ParPak(It was a lucky guess).Food serive materials Fred? Did you realize this in the middle of a taco frenzy at your local brew-pub?Dan

4. 
   andrew_d | Nov 22, 1999 03:55am | #8

   *So there's a use for all those used Burger King boxes? Attic insulation?

2. 
   MarkJ_from_Pa | Jan 04, 2000 11:38pm | #9

   *
   I was called in look at a 10 year old frame house recently, for the purpose of adding insulation to the attic. There I found a large downflow furnace unit in the attic which causes some serious ice dams. The attic has 6 inches of fiberglass, with ridge and eave vents. The eave vents were not baffled. What I need to know is if this can be fixed by adding baffles at eaves and more insulation, or possibly a power vent.