We are having a 2 Story Farmhouse built in northern Mass. We found water dripping through the farmers porch on a warm day last week (early march). The porch is below another roof, snow collects on the porch roof (see Pic, sorry do not have pic of snowy roof).
Is is unreasonable for me to think that we should not have to deal with ice dams in a new construction home in northern mass?
What would be the correct way to remedy this?
Thank you for your input.
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Replies
I'm not sure what your code says about ice barriers over unheated areas or in this case, an area where the ice shield cannot extend 24" inside the exterior wall line of the building, but a leak is a leak. Have your builder repair it. Could it be from flashing at roof-house connection?
What would I do? Remove roofing down to sheathing, apply ice shield to entire roof, re-shingle.
Thanks RichinVA think that I am going to push for the ice and water.
An ice dam should generally not occur unless the roof is too hot. Is the "attic" area properly ventilated?
I don't think that roof below the second story is vented. I am not sure how that would be achieved, There is a cor-a-vent product (invent?)that I saw a few months back for mid roof venting.
What is the sun exposure? Could it be that heat is getting into the space from inside the house?
It is facing do north.
Could water dripping from the upper roof (in the sun) freeze in the snow lower roof (in the shade) and cause an ice dam?
I don't know how heat would get in to the space... the house is well insulated with 2x6 blown in fiberglass and Zip R sheathing. The space is sort of vented with a ridge vent that is hidden from view by the garage.
thanks again DanH
User,
Is the dark spot on the floor in the second picture where the leak is?
Was the thaw during a warm up? Was the snow on the porch roof up against the siding?
I see two potential problems that might do it.
1 has already been mentioned, the ice/water shield. I would have run it all the way up and then turn it up the sidewall maybe a foot. Counterflash and housewrap down over that.
And, I would never place windows that close to the roof. The flashing of those would be critical at the roof line. If that isn’t detailed properly, that might let enough water in.
You also have a valley that runs close to above that light. Any idea how that was flashed at the high point?
An ice dam forms when snow melts on the roof and then freezes, as it nears the edge.
Usually what happens is that the roof is too warm due either to heat from the inside or from sun hitting bare parts of the roof (often on the other side). So snow melts and runs down the roof -- no problem unless the edge is colder. But the edge usually is colder, if there's any significant roof overhang, and so the water freezes along the edge, creating a "dam". The (damn) "dam" collects water behind it (higher on the roof) and this water then runs under the shingles and gets into the structure.
But you have a non-standard situation. It could be that the water is dripping off the roof above (where snow is melting due to either/both of sun or heat leakage from the inside), or the water could be coming from the shed roof itself. You need to study the situation and decide which factors are most likely.
You think you've got an ice dam.
The lake was the result of an ice dam on the Clark Fork caused by the southern encroachment of a finger of the Cordilleran Ice Sheet into the Idaho Panhandle (at the present day location of Clark Fork, Idaho, at the east end of Lake Pend Oreille). The height of the ice dam typically approached 610 metres (2,000 ft), flooding the valleys of western Montana approximately 320 kilometres (200 mi) eastward. It was the largest ice-dammed lake known to have occurred.[3]
https://en.wikipedia.org/wiki/Lake_Missoula
It should be noted that there is another situation that can sort of mimic ice dams. This is where, during extremely cold weather (generally below zero), moist air from inside the structure migrates to the corners of the attic and freezes. Then, when it warms up, the ice melts and drips down through the ceiling/soffit. This can occur even if there's no snow on the roof. The amount of water in such cases is generally much less than produced by ice dams, however -- just enough to stain the ceiling.
Ice damming can happen to any gutter — clean or dirty, new or old because it is not caused by faulty installation or destructive roofing components. Ice dams occur when cold air around the soffit meets warm air inside the shingles right above the soffit.
Applying many De-icing Methods, such as heating cables, blowing hot air from the interior, etc., can give you temporary solutions to your problem. But for a permanent solution, you should hire a professional Ice damming specialist who provides permanent fixes for Ice Dams so that you can enjoy dam-free winters.
There doesn't appear to be gutters on the 2nd floor roof, plus a rather large upper roof watershed, most of the water lands on the porch roof.
First priority - gutters on at least the upper roof.
Next priority, reflash the porch roof to wall connection.
Fix everything disturbed and move on with life. There are always challenges that accompany home ownership.