This comprehensive Ice Dams Guide covers the causes and effects of ice dams as well as prevention methods.
The winter is in full swing and most roofs in the northern states, as well as all of Canada are covered in snow. While most of these roofs don’t leak when it rains, they will leak in the winter, when the snow and ice are on the roof. Many homeowners are experiencing an ice build-up along the drip edge of their roofs, and this build-up is called Ice Dams. Ice dams can look very innocent, but they can pose big problems for your home, as well as your well being. From a simple icicle falling on you, to a complicated and expensive removal of mold growth in your attic, which can cause asthma and other respiratory issues.
If you have ice dams on the roof of your house, you may get rid of them yourself (below we will explain the most efficient way to remove them) or hire a contractor to do it for you – you can find local roofing contractors. Trying to remove ice dams yourself can be dangerous, so we do recommend hiring a professional for the job.
What causes ice dams?
Ice dams are caused by a combination of poor roof ventilation, and inadequate attic insulation. The basic process goes as follows:
- Due to poor insulation the warm air from inside your home escapes into attic space.
- Because the roof is not ventilated, or has poor ventilation, the warm air cannot escape from the attic, so it starts warming up the roof.
- When snow falls on the roof, it begins to melt, as roof temperature is above the freezing point.
- The melted snow turns into water, which runs down the roof, and when it reaches the overhangs, which are not heated at all or not as much as the rest of the roof, water freezes along the edge, forming ice build-up.
- As ice build-up along the edge grows, in turns into a barrier, which prevents the melted water from going over – hence the term Ice Dam.
- As more melted water hits the ice dam, it begins to “pool” and has nowhere to go, but under the shingles above it – see the diagram below.
Effects of Ice Dams
Ice dams are costly to have and costly to eliminate, but the sooner this issue, the more economical it will be. Here is a summary of the ways you are losing money due to ice dams:
- Your roof leaks, so you have interior damages, which need to be fixed.
- Your roof has to be fixed.
- Your roof deck and framing will rot and will need to be fixed.
- You are losing heat, which means you are paying money to heat unused attic space and to melt the snow on the roof – a very expensive and unproductive way to spend your money.
- Ice dam leaks dampen (wet) your wall insulation, reducing its insulating properties, which means you have to spend even more money on heat.
- If unchecked, the damages caused by ice dams can cost you thousands of dollars to repair, as well as hundreds in lost heating costs.
If you let the ice dams problem go for a prolonged period of time, your attic space may experience mold growth, which can cost as much as $10,000 to remove, and a home insurance company may often deny coverage, because you did not take steps to resolve the problem (negligence).
Prevention – How To Stop Ice-Dam Roof Leaks
Quick DIY methods:
First and foremost – if you attempt to fix the ice dams yourself – do understand that it can be very dangerous. Use utmost care, and also spend an extra $20 for a ladder stabilizer – it will make your job much easier and safer. In any case, we assume no responsibility if you injure yourself or others – do it at your own risk.
One of the easiest and quickest ways to get rid of ice dams is to use socks filled with calcium chloride or rock-salt (sodium chloride), and to place them along the roof edge, as well as around chimneys and skylights to melt the snow. While this method works, it requires constant replacement of rock salt in the socks, and having to climb up the ladder multiple times. This is dangerous in the winter, especially that most homeowners do not have a ladder stabilizer, so the ladder can easily slide left or right.
Also, note – while calcium chloride should be safe to use on most roofs, we recommend you contact your manufacturer to make sure that it’s safe to use it on your particular roofing product.
Additionally, you can use special heating cables along the roof edge to melt the ice dams, before they form. This is a more common method, and is used more often, as it does not require you to constantly go up and down the roof all winter long. There are a few downsides to this method. First, these cables are expensive to install. Second, most roofers will install them by simply placing a screw (which holds down the heating cable) through the roof, and this can cause leaks. Another drawback is that you are actually fighting a heat and energy loss problem with more heat and energy waste, instead of solving the problem, which causes ice dams.
Gutter heat cable cost about $80 for a 160 feet long cable, use 120 volt AC current, and you can rather easily install them yourself. If you decide to install them yourself, you will first need to get rid of the ice on your roof. Then, when you actually go to attach the cables, try to mount the hangers under the shingle tabs, so that your roof would not leak through the fasteners. Continue reading