Construction Design-Fixing Ice Dams from the Interior, Part 1

Today, I’m starting a 2 part series on how I plan on fixing the ice damming on the roof of my 1952 Cape.  This first part is going to show photos of my neighborhood, which has many houses suffering from the same condition as mine.  If you’re following me on Instagram, you may have already seen some of these photos.

Before we get started, here is a drawing showing the definitions I will be using to describe the 1/2 story upper level.  My home, which is a Cape design, has these features.

This first pic is a home a couple blocks from mine.  Notice how there is still some snow on top of the roof and at the eave, along with the nice ice dam.  This photo is suggesting that there is not enough insulation and/or poor roof ventilation at the sloped ceiling portion of the roof.  There is good insulation/ventilation at the very peak.  You can see a vent at the very peak of the gable wall.  It also appears there is good insulation at the eave, probably in the knee wall area.

This next photo shows both a digital and thermal image of another story and a half home with a sloped ceiling.  This home is void of all snow on the roof with the exception of the eaves.  These photos were taken when outdoor temperatures were around -20F and the temperature of the roof at that time was 27F.  I’m sure when the temperature rises to around 0F, this roof is well above freezing which is leading to the snow melt and ice dams.

This story and a half home has similar issues.  Notice all the snow that is on the unheated porch and what is left on the roof.  Some of those icicles are over 8 feet long.

This is another home with a sloped ceiling, (actually a gambrel roof), things get more complicated when a dormer is added.  Notice the river of ice flowing down the left side of the dormer.  This home would be a challenge to get the insulation, air sealing and roof ventilation correct when building new today.  These critical details were missed when this home was built, more than 50 years ago.

What do all these homes have in common?  They all have the sloped ceilings in the upper level and were all built before 1970.  Air leaks, low insulation levels and inadequate roof ventilation all become evident during the winter months.

And now, my home.

This first picture is over the back door.  This ice dam is nearly a foot thick.

The front of the house, this ice dam is over a foot thick.  As you can see, I have similar issues to the other homes I showed.  What’s my plan for fixing the problems?  We will get into that next week.

Leave a Reply

Your email address will not be published. Required fields are marked *