1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)
Thread Status:
Not open for further replies.
  1. henkmeuzelaar

    henkmeuzelaar New Member

    Joined:
    Nov 26, 2010
    Messages:
    209
    Loc:
    Targhee NF, ID
    I agree that a "cold roof" over an attic with good ventilation and a carefully insulated floor is in many ways the simplest and best solution, provided you religiously insulate any vent, flue, chimney or roof a/c ducting that traverses the space between attic floor and roof. In principle, this insulation should extend to well above the expected snow level in order to make sure no warm air, etc., can cause melting of the snow on top of the roof. In practice, that is rarely done, I believe. As a consequence, any snow that melts around these roof perforations (as you can see happening on roof tops all around you) will freeze out again somewhere on its way down; usually over the eaves. thus forming an ice dam.

    This is probably one of the main reasons one finds relatively few newer houses with attics here in the high altitude Rocky Mountains areas. Instead, we mostly see cathedral roofs because of better space utilization, better daylight ingress and easier roof access for the various heating, cooling and other ducted devices of todays households.

    Even in cathedral roofs, however, the "cold roof" principle is getting more popular nowadays, despite the very high cost of construction. Essentially, this requires the construction of two separate roofs with the inner roof heavily insulated (usually at the R39 or R50 level in our nick of the woods) and separated from the outer roof by a 1/2 to 1 foot high vented space.

    Henk

    Helpful Sponsor Ads!





  2. gfreek

    gfreek Minister of Fire

    Joined:
    Nov 5, 2010
    Messages:
    754
    Loc:
    Beautiful Attica/Varysburg,New York
    Gutters tend to increase the problem also....
  3. Dougsey

    Dougsey Feeling the Heat

    Joined:
    Aug 3, 2006
    Messages:
    335
    Loc:
    Epping, NH
    Don- What is the copper pipe I see in your pic?
  4. wilburg

    wilburg Member

    Joined:
    Oct 20, 2010
    Messages:
    163
    Loc:
    Western Mass
    What I did to atatch a Garden hose to my shower:

    1) get an adapter for a handheld shower head (silver piece)
    2) fit an adapter for a 3/4inch hose (brass piece)

    I bought both pieces at home depot.

    I mostly use this to wash my dogs with warm water outside of the house, but also works for my ice dams

    (photo is sideways)

    Attached Files:

  5. peakbagger

    peakbagger Minister of Fire

    Joined:
    Jul 11, 2008
    Messages:
    1,722
    Loc:
    Northern NH
    One overlooked cause of ice dams on homes with proper insulation and clear soffit vents is blocked ridge vents. Many new homes have ridge vents only with no gable end vents. The ridge vents work great until a big snow storm covers them over, then the attic warms up and its ice dam time until the vents are clear.

    By the way, most newer roofs in snow areas are rated for 40 pounds per square foot live load. Once snow starts getting over 4' the roof is probably at or near design load. Very rarely does a roof fail slowly, usually it fails from a defect in the original construction and when they go, they usually go quickly.
  6. henkmeuzelaar

    henkmeuzelaar New Member

    Joined:
    Nov 26, 2010
    Messages:
    209
    Loc:
    Targhee NF, ID
    Our old Utah home, in Summit Park at 7,200 ft has 90 PSF roof snow load requirements and in nearby Park City the homes at 8,400 ft need to be constructed for no less than 160 PSF.

    However, since we do have the occasional 300 - 400 inch snow year, we certainly have gotten up on the roof to shovel snow from vulnerable porch and other overhang sections, especially when the groaning timbers would start waking up my wife at night. When you are shoveling down a 6ft, highly compacted snow layer you can occasionally feel the roof rise under your feet, like when you are boarding an airplane just when the automatic load leveling kicks in....

    Henk
  7. SmokeyTheBear

    SmokeyTheBear Minister of Fire

    Joined:
    Nov 10, 2008
    Messages:
    12,556
    Loc:
    Standish, ME
    The insulation I have is good enough, no ice dams. No valleys. Vents are all free, Old hand at dealing with ice dams and other roof issues so I just watch the snow load, one thing when it is the fluffy stuff, entirely different matter if it is the wet stuff. If I move the snow off of the rear (or is it the front) deck when it gets 3' high I have to move 32 cubic yards of it. Pain in the back, arms, and other anatomical parts of this geezer.

    My wife has been picking away at the deck since it looks like the roof is going to need raking this year.
  8. Don2222

    Don2222 Minister of Fire

    Joined:
    Feb 1, 2010
    Messages:
    7,157
    Loc:
    Salem NH
    That pipe is the vent pipe for the bathroom sink. Copper was cheap back in 1962 when the house was built. LOL
  9. SmokeyTheBear

    SmokeyTheBear Minister of Fire

    Joined:
    Nov 10, 2008
    Messages:
    12,556
    Loc:
    Standish, ME
    Told ya, not to post pictures like that, too many of us geezers can still see ;-).
  10. Don2222

    Don2222 Minister of Fire

    Joined:
    Feb 1, 2010
    Messages:
    7,157
    Loc:
    Salem NH
    Ok Smokey I just cropped it out. :)
  11. peakbagger

    peakbagger Minister of Fire

    Joined:
    Jul 11, 2008
    Messages:
    1,722
    Loc:
    Northern NH
    for folks in NH, here is a study on recomended ground snow loads by town.
    http://www.senh.org/committee reports/tr02-6.pdf
    A roof should be built to withstand these loads, unfortunately in the rural towns where the loads get quite high, the towns dont have building inspectors and therefore even though folks are supposed to build to a high snow load, they usually dont.
  12. Xena

    Xena Minister of Fire

    Joined:
    Nov 30, 2005
    Messages:
    2,491
    Loc:
    South Shore MA
    I had a small leak coming in my bedroom this morning.
    The drip woke me up @ 6 am. Went out there when it
    got light out and raked another foot back from the edges
    of the roof around the entire house, and the leak stopped shortly after even though
    there is a few inches of ice there and the gutters are filled
    to the brim with ice.
    We have good insulation, soffit vents and a ridge vent
    but my brother painted the house this year and was lazy
    and painted over the soffit vents so they are blocked.
    He's been away for the weekend but when he gets home
    he will be getting his ass up on a ladder to rake the snow
    that I couldn't reach from the ground. More white stuff
    coming tomorrow. Oy.
  13. nh1234

    nh1234 New Member

    Joined:
    Dec 12, 2010
    Messages:
    32
    Loc:
    Southern NH
    Been reading all of this great stuff about ice dams..cause and effect stuff. While proper construction can minimize the problem it is not always possible to revise mistakes made in original construction. Two years ago I had BIG problems with ice dams and then of course water damage. Did a LOT of researching and a lot of possible resolutions do not work. Finally found a resolution
    while it is NOT cheap it will resolve the issue. Go to the folling link and check it out http://www.bylinusa.com/roof_ice_melt/RIM.html
  14. henkmeuzelaar

    henkmeuzelaar New Member

    Joined:
    Nov 26, 2010
    Messages:
    209
    Loc:
    Targhee NF, ID
    Yeah, that looks like a technically satisfying technology.

    Although installation is probably quite costly if you don't already have a proper aluminum roof skirt installed I think there are a number of ways DIY installers can achieve safe and effective results; e.g. by burying a heat cable under an existing skirt (so it does not get damaged by the ice and does not just form ice tunnels/caves but spreads the heat out over a much larger area.

    The biggest problem are the monthly operating costs. At 36 W/ft power consumption, let's say over a 100 ft long roof edge, we are talking 3.6 kW
    If you need to run this for an entire month you could use up more than 2600 kWh. In many areas this could set you back 300 to 500 dollar per month, just for keeping the ice from the roof.

    I know that with proper control and regulation, you could probably reduce that by a factor 2 or 3 in milder climates or winters, Yet, when I see numbers like that (added onto the installation cost) I would rather spend my money on trying to achieve a properly insulated roof.

    Henk
  15. nh1234

    nh1234 New Member

    Joined:
    Dec 12, 2010
    Messages:
    32
    Loc:
    Southern NH
    I totally agree about the possible cost of installation AND I am NOT happy about the ongoing cost to run the damned things..BUT I was less thrilled about the water damage and cost associated with that. I installed it myself (not difficult) and it seems to be working great..will NOT be happy to get the electric bill BUT and very happy right now that I do not have water running into the house. If it were at all possible I would have chosen trying to fix things with proper ventilation. Just thought I would let people know what is out there.. Last poster did a great job of reviewing the product and discovered the pitfalls very quickly.
  16. SmokeyTheBear

    SmokeyTheBear Minister of Fire

    Joined:
    Nov 10, 2008
    Messages:
    12,556
    Loc:
    Standish, ME
    For what it is worth 70 lbs per square foot is code where I am.
  17. slls

    slls Minister of Fire

    Joined:
    Jun 9, 2008
    Messages:
    1,457
    Loc:
    central maine Lat 45
    Home made, 25 ft long aluminum 1 inch tubing, 2 aluminum licence plates attached on the end.
    Rake a story and half house. Tubing was from a huge TV antenna given to me. I believe it's the only one in captivity.
    I only rake one side of the house, where the sun hits most, melts then freezes at the eves, other side doesn't bother.
  18. SmokeyTheBear

    SmokeyTheBear Minister of Fire

    Joined:
    Nov 10, 2008
    Messages:
    12,556
    Loc:
    Standish, ME
  19. henkmeuzelaar

    henkmeuzelaar New Member

    Joined:
    Nov 26, 2010
    Messages:
    209
    Loc:
    Targhee NF, ID
    Ah, great Idea!

    We just switched Utah license plates for Idaho ones (hope my wife did not yet throw them away....).

    Henk
  20. Czech

    Czech Minister of Fire

    Joined:
    Jan 20, 2006
    Messages:
    1,065
    Loc:
    Twin Cities, MN
    Two things really quick, not sure if mentioned. Rather than adapt your shower head, what's wrong with the clothes washer hook up or water heater drain to connect a hose? Both are most likely male hose thread. For soffet vents, a leaf blower from the outside in during the nicer months assures that your blown in insulation is not covering the vent.
  21. Shortstuff

    Shortstuff Feeling the Heat

    Joined:
    Jun 5, 2008
    Messages:
    461
    Loc:
    Southeastern MA
    Here's just a peek at what I tried to get off my roof today. Just to the left of the chimney there's a valley that actually had a measured 40" of snow in it which is now gone. I'll be sore tomorrow.

    Attached Files:

  22. jumpink

    jumpink Member

    Joined:
    Sep 20, 2010
    Messages:
    149
    Loc:
    Northern New Jersey
    Thanks Smokey. All the retailers are sold out on the rakes, looks like I have to get creative and improvise.

    I have huge ice dams all around the entire house. I thought it was because I never cleaned out the gutters in the fall but reading this post makes me think it is more like an insulation issue.
  23. Kevin Willis

    Kevin Willis New Member

    Joined:
    Jan 25, 2011
    Messages:
    21
    Loc:
    Central Oregon


    That is some nasty looking ice, It must be one well built house. I have never seen ice like that except at the lodge snow skiing or something. wow
  24. Don2222

    Don2222 Minister of Fire

    Joined:
    Feb 1, 2010
    Messages:
    7,157
    Loc:
    Salem NH
    Hello

    Any ideas on this?

    I have good insulation but I still have a premature melt line from the sofit all the way up to the ridge right where the Vent pipe is??
    It makes more icicles on the overhang outside the bathroom window and drives me nuts

    So what do I do to prevent this?

    Pic 1 & 3 shows issue

    Pic 2 shows aluminum foil coated foam board I screwed into the 2 rafters where the vent is from the sofit to the ridge as a possible fix??

    Attached Files:

  25. Shortstuff

    Shortstuff Feeling the Heat

    Joined:
    Jun 5, 2008
    Messages:
    461
    Loc:
    Southeastern MA
    Don2222 it looks like that is a PVC pipe. It wouldn't hurt to add another foot or two with a coupler would it?
Thread Status:
Not open for further replies.

Share This Page