Published on March 23rd, 2014 | by Henri0
Icicles return despite improvements to roof
Q. I have your book and follow your posts constantly. EXCELLENT RESOURCES!! Please keep this up as it is a tremendous source of unbiased information, based on actual experience, for us home owners.
My problem – 4 years ago I had a new roof (50 year warranty) put on my Ranch home built in 1960 in Massachusetts. The roofer installed “two” rows of ice & water shield and the Shingle Vent II ridge vent system, with a new Drip Edge with an 8 inch lip that went under the Ice & Water shield. He replaced all plywood that looked to be damaged.
Because of the aforementioned, he told me I no longer had to use my roof rake to remove the accumulating snow at the roof edge. In the past I always raked the snow from the roof edges for about three feet.
All was well until this year. During the recent thaw/freeze cycle, I noticed about a 3 inch thick ridge of ice on the roof edge. Since the roof pitch is 5/12, or 22 1/2 degrees, I assumed the 72 inches of Ice & Water shield was more than adequate to stop any water problems. Well, I was wrong – as you can see from the attached pictures icicles have formed on the siding and icicles are coming out of my soffit vents. From the attic I could see water and icicles on the “inside” of the soffit board, no water was on the attic roof plywood. The outside of the soffit board was completely dry, indicating the water was somehow dripping behind the soffit board, but I cannot understand how this is possible. Any advice is extremely welcomed.
A. There is no way that a 3-inch ice dam would create a melt-water backup high enough to penetrate the roof above the 6-foot mark of the Ice & Water Shield (I&WS) with a roof pitch such as yours if the I&WS was installed properly. There is something wrong in this picture.
The first thing that comes to mind is that the gutters filled with ice, and further melt water backed up under the roof sheathing into the eaves because the bottom of the drip edge is above the gutter and does not seal the joint between the fascia board and the roof sheathing.
But one of the photos you sent me shows the inside of the gutter, and it is clear, so this can’t be the problem.
The fact that you found the plywood sheathing dry and only wetness on the inside of the soffit would indicate that the water penetration is not through the I&WS or the roof sheathing above it unless the water has had the time to dry, unlikely in this cold weather.So it sounds as if the water penetration is at or near the eaves.
A correct installation is to install the drip edge over the bare sheathing and to cover it with the I&WS, which needs to be installed on bare sheathing. Is it possible that the roofer did this installation over a layer of felt remaining from the previous shingles? That seems very unlikely, but I have seen it once before with results similar to your situation.
At this point, you should ask the roofer a few questions based on the above and to come take a look to see if he or she can find what the problem is. Will he or she be willing and cooperative? Another option is to have a professional engineer look into the problem. It is somewhat a puzzler without some explanation of how the roof was installed.
By the way, the soffit vents the photos show are not he best venting for a ridge/soffit combination. They should be continuous along the entire soffits.by