Did you know that many older homes are either without felt or have deteriorated felt between their slate and wood deck? This does not provide adequate protection during harsh winters. When there is a heavy snow accumulation on the roof, the warm temperatures from inside the house can melt the snow at the bottom of the accumulation causing water to run toward the eaves. As this water runs to the eaves, it refreezes because the soffits are unheated. This can result in an ice dam at the perimeter of the house. Subsequent melting can run into this ice dam and leak into the house behind the fascia board or through the roof decking if there is not adequate dripedge or high-back gutters along with ice and water shield around the perimeter. The Durable Slate Company has been keeping homes safe and dry with reliable underlayments and high-back gutters for more than twenty years. This type of preventative maintenance is crucial to the upkeep of your slate roof and is a permanent fix. Make sure you rely on an experienced and trusted company to protect your home from this kind of damage.
Tim Carter talks about gutter ice, a similar problem, here.
Helpful information on insulation and venilation can be found here.
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6 comments:
Let me give you some tips for ice dam prevention
1.Proper insulation and ventilation required.
2In the attic scenario only the floor of the attic should be insulated, not the underside of the roof!
Proper ventilation is also required.
3.Outside air needs to be able to enter the attic so that the attic temperature is the same as the temperature outside. You achieve this ventilation through the use of gable vents, soffit vents and a roof ridge vent.
Does Durable Slate install drip edges with slate roofs? My roofer told me that slate acts as its own drip edge, making bent metal ones unnecessary. Phil
Hi Phil,
In some instances, The Durable Slate Co. does install drip edges. However, the drip edge pretty much just controls the water flow so that the water goes directly into the gutters. Plus, it gives a cleaner, more aesthetically pleasing look.
The only way to truly protect your roof against ice damming is with a proper underlayment and/or high back gutters. Hope this answers your question.
Amber
I'm really disappointed to see and article like this from a company I respect like Durable. Slate roofs don't need underlayment. Situations where ice dams can occur should be handled with high-back gutters or saddles constructed of lead, stainless steel, or copper. Underlayment was not used on many of the 100+ year-old roofs that we restore and they have never suffered from leaks due to lack of underlayment. Promoting a fallacy like this is bad for the industry and durable should know better. I know they employ some great slaters and tradespeople that understand this is a lie.
Kurt,
Jack Jenkins, an employee of Durable and veteran in the slate roofing industry responds to your comment below:
"Kurt's passion for slate roofing comes through loud and clear in his comment. As someone who has 17 years of experience myself, I share his passion and would like to give my thoughts on this subject.
In simplest terms, ice damming is caused when a large amount of snow builds up on a roof. This snow melts partially from the heat loss of the house or the sun and then refreezes during cooler times. This can sometimes cause the gutters and even the downspouts to fill up with melted snow and refreeze to the point that water can no longer move to the downspout. This excess water can, in some cases, be pushed back up the roof, due to the weight of the snow and ice because it is trapped and blocked by frozen gutters. This water can then be forced under the slates and cause interior damage.
In my many years in the industry, there are a few absolutes I have learned. One of them is this: if you ask four different slate roofers the same question, you are likely to get four different answers. This is usually based on each person's experience, or based on the years of experience they've actually had up on the roof. So I have learned to respect everyone's opinion, and try to learn what I can. If my experience causes me to have a different opinion, I label it as such and keep an open mind. Another absolute I have learned is that rarely are two old slate roofs the same. Most historic homes were built by individual builders, not developers following a standard set of plans.
That being said, it is safe to say no two situations are exactly the same. Some homes can benefit from ice guard underlayment and some require a different solution to the problem.
One of the questions that is sometimes raised is, "Why did this roof not experience ice damming leaks before now?" And there are a few different answers:
1. When the house was built it may have had a good felt paper that prevented ice damming, but the felt has since deteriorated.
2. It may have had half round gutters that stood away from the fascia and allowed the water to fall behind. These may have been replaced with modern gutters that are tight to the fascia and now allow the water to be forced under the slates.
3. When the house was built, the trees around the house might have only been 10 feet tall. This allowed the roof to get a sufficient amount of sunlight to quickly melt snow. Those same trees might now be 45 feet tall thus changing the amount of sunlight that hits the roof. This changes the natural exterior envelope dynamics.
The other arguments usually address the slates themselves being damaged or improperly installed. In the rare occassion that this is true, we replace the damaged slates and our warranty supports this. In the argument that the bottom rows just need more head lap, I would pose the same question those opposed to underlayments would: If the roof just needs more head lap at the eaves, why hasn't it leaked every winter since it was built?
So here is our overall professional opinion on the subject: In our 23 years in business we have discovered ice damming to be a problem for many of our clients. Rather than debate all of the peripheral issues surrounding this topic, we researched solutions. One of the solutions we approve of is underlayment and in some cases high back gutters with an underlayment. This maintains the integrity of the original slate roof while correcting the client's ice damming problem. The facts speak for themselves.
I am not interested in having an ongoing debate; I respect all opinions, as I will with anyone else who chooses to disagree. But Durable Slate's purpose is to solve problems with slate and tile roofs and provide a solid solution we can stand behind.
So if you think ice damming may be occuring on your roof, call a roofer you trust. Or maybe you should call a few and gather solutions from all of them. Ask them to support their claims with references and move forward with the one you feel best about."
Jack Jenkins
VP Business Development
The Durable Slate Co.
Jack, a great response indeed. Certainly every situation is different and not every historic roof is built well, but many of them are functioning well with no underlayment. I was irked by the tone of the article which seemed to suggest that IWS or some other type of underlayment is required to prevent Ice-damming. It is not required and should not be relied on to keep an eave dry. Sheet metal is the best way to do it. Also covering an entire roof deck with grace, iws, or any of the "premium" underlayments causes problems for repairs in the future. If a leak occurs in the future it should be able to fall through gaps in the decking close to the source rather than being carried to the gutter by underlayment. This way leaks can be detected quickly rather than festering for years and requiring extensive repair work in the future.
I know the quality of your gutter work can be trusted without having to rely on underlayment. This seems like a scare tactic to drum up business from people that may or may not have anything wrong with their roof.
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