New Jersey home inspectors should be familiar with what ice dams are how they form and what corrective actions a client can take to minimize the issue. An ice dam is a buildup of ice that builds at the edge of the roof close to the gutter. The buildup creates a dam or a wall that prevents show melt from getting to the gutters. Over time the ice dam will get larger that water flowing toward the roof edge will get trapped behind the ice buildup. This water can back up under the roof shingles and enter the home. Leaking water can cause damage to ceilings, walls and flooring and lead to mold growth behind the walls.
Ice dams are formed because heat is escaping into the attic space of the home. Heat from the home enters the attic making the attic hotter which in turn melts the snow off the roof. This water run off flows toward the cold roof edge then freezes causing the dam to form.
Ice dams can occur when the following conditions exist. There has to be snow on the roof top. The exterior temperature must be below freezing (32 degrees F). The roof surface temperature must be above freezing while the edge of the roof has to be colder below freezing. if these conditions are met ice dams can form.
New Jersey home inspectors should understand how ice dams can be prevented. Ice dams can be prevented by properly insulating and ventilating the attic space. band aide type solutions are also seen such as installing heat tracer cables, but these are not true reliable fixes they are just temporary. Ice dams start with heat loss from the home into the attic. By keeping the roof below freezing the snow will not melt. Minimizing air loss starts with sealing all pathways of hot air into the attic space. All penetrations such as piping openings, and duct work openings should be sealed. High hat lights are challenging to deal with, but they should be IC type and insulation should be installed tightly around them with the use of LED bulbs that burn cooler. Sealing air leaks is a first step but insulation must also be added to the attic floor. Attic floor insulation must be about 13 inches thick to produce an R-rating of about 40. The preferred insulation is blown in cellulose because this loose fill insulation can be distributed around all areas and makes for a tighter seal leaving fewer openings or gaps where air can leak into the attic from the home. Although popular fiberglass batts leave gaps and openings and are not as good at stopping air leaks.
The next big prevention step is to improve attic insulation. Improving attic ventilation helps to cool the attic space and remove hot air. There should be at least two different types of ventilation. One is a ridge vent and the other is soffit venting. The purpose of ridge venting (high in the roof) is to allow for hot air to escape the attic space. The ridge vent helps in cooling the roof, helps prevent condensation problems, and prevents damage.
Soffit vents sit lower in the roof under the eaves. Soffit vents provide a consistent flow of air into the attic space. This increase in air flow will help to minimize ice dams because the attic will remain colder in the winter months. It is challenging to figure out the exact amount of attic ventilation in a home but a good rule of thumb is to have one square foot of ventilation for 300 feet of ceiling area. More is actually better. It is desirable to have a professional determine the appropriate size of the attic ventilation that is required.
If your home is prone to ice dams and the roof is easy to access (1 story) you may want to try to rake the snow off the roof. A snow rake can be used which is secured to a telescoping metal pole. If the snow gets removed from the roof it will not be able to create ice dams. You should never use a roof rake on a two-story roof. Standing on a ladder with a long rake is unsafe. When raking a roof care must be taken in order to avoid damaging the roof shingles which get brittle in the colder weather.
Another popular option at ice dam correction is the installation of heat cables. These heated cables must be plugged into a GFCI receptacle and be installed correctly to be effective. These cable use electricity to generate heat through the cables. These cables can create a pathway for melted snow to travel to the gutters rather than building up ice dams. The cables create channels only and do not keep all snow from collecting at the roof edge. These cables although effective need to be installed by a professional. They are not a catch all nor are they 100% effective.
Home inspectors in NJ should be able to identify the damage done by ice dams. Water damage can typically be seen on the ceiling areas where the walls meet the ceiling at the outer walls of the home. Ice dams can also damage walls and flooring and wet insulation creating conditions that can cause mold. Mold can grow in 48 hours and develop inside the wall cavities in a home that has ice dams. This type of mold is challenging to see but home inspectors should be on the lookout for mold at the wall and ceiling intersection and also under the eave areas of the home in the attic space. Ice dams can also damage roof shingles. Home inspectors should be on the lookout for damaged or torn roof shingles at the eave areas of the home. Ice dams can also cause damage to gutters the weight of the ice buildup can pull gutters off the home and create bellies or low areas. Ice dams can also cause damage to exterior soffits. Home inspectors should be inspecting for soffit damage. Homes that are prone to ice dams often have water staining and water damage to the soffit areas.
New Jersey home inspectors should be familiar with how ice dams are formed and be able to identify the damage caused by ice dam formation. Home inspectors should be able to educate clients on possible corrections and provide recommendations regarding ice dam control.