Wednesday, June 3, 2009


Confronted with water running into your home and seeing ice accumulated on the roof edge or guttering, it's easy, in the midst of a panic, to assume that either the roofing or the gutters is the culprit -- particularly if you've never had the problem before and just had new roofing, gutters, or gutter protection installed.

Actually, neither the roof, gutters, nor the gutter protection can ever be the cause of the problem. The cause of the problem is either inadequate insulation, ventilation, or both. Heat loss through the roof causes snow to melt. The melted snow (water) runs down the roof and when it crosses the eve line, where temperatures are colder, the water freezes and builds up as much as 8" high wall -- effectively, a dam. Remember the roof is warmer where you have heat being lost through it from the attic so water is trapped on the roof behind the ice dam and can then seep through openings in your roofing and into your living space.

How to eliminate ice dams:
1. If your attic space is unfinished (not used as a living space), the goal is to have the temperature inside the attic within a few tenths of a degree of the outside temperature. To accomplish this you need:
a. insulation of R49 or greater between the floor joists of the attic;
b. soffit or fascia vents;
c. roof or ridge vents;
d. all sources of heat loss, such as bathroom or kitchen vents, heating ducts, or heat pumps, well insulated to minimize loss of heat from them to the attic space.

Doing all the above allows cold outside air to come in at the bottom of your roof and escape through the top of the roof taking along any heat lost to the attic space.

If you have all the ingredients and are still experiencing a problem:
a. inspect the insulation in the floor to insure it's not jammed against the end of the roof to close off circulation from the soffit vents; if it is, then pull the insulation away from the roof edge to allow air to circulate;
b. inspect soffit vents to see that they are open and not painted shut. Some- times vinyl soffit vents are installed over solid wood soffits making the vinyl vents useless. If so, remove vinyl soffits and drill 2-or-3" openings through the solid wood soffits every 12-to-18" respectively;
c. check roof vents. If only a power vent is available for summer venting, either have additional roof or ridge vents installed or have your electrician install a bypass switch enabling the power vent to be turned on when there is snow on the roof;
d. close any open gable vents. Air can short circuit by coming in gable vents rather than by coming in the soffit vents.

2. If your attic space is used as a living area and you have soffit and roof vents, fixing the ice dam problem can be expensive. You need to allow air to flow between the roof and the insulation. The ceiling and insulation must be removed, special ducting panels must be installed between each rafter, then the insulation and ceiling can be reinstalled.

If the roof area can not be effectively vented, there are two remaining courses of action:
a. have an ice shield barrier installed along the roof edge. Existing shingles must be removed along the roof edge. The barrier is 36" in width -- ample for steep or high pitched roofs. If you have a low pitched roof you may need two widths installed. The shield is like a pool liner and doesn't allow water to seep through it.
b. install heat tapes along roof edge, guttering, and downspouts, if required. The disadvantage is that heat tapes must be turned on and off manually and can burn out if forgotten and left on.

Ice dams are not the only kind of ice damage you can get. Ice and snow in your gutters can be adsorbed by the wood fibers of the fascia board, acting like a wick and sucking in the melted snow, which leads to rot of the fascia and rafter ends, thus creating a fertile environment for carpenter ants. Gutter protectors, like the Waterloov® gutter protector, do keep ice and snow out of the gutters and eliminate ice damage by osmosis; however, gutter protectors do not contribute to or help eliminate ice dams.

In summary, making sure winter time ventilation is functioning properly is a way of making sure your Waterloov Gutter Guard Installation will be free of icicles.

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