Replies

1. 
   frammer52 | Aug 29, 2008 06:12pm | #1

   2 feet past the edge of the house, at least that is the rule in NY.

2. 
   adkins | Aug 29, 2008 06:23pm | #2

   24" in MA, too...

3. 
   dovetail97128 | Aug 29, 2008 07:53pm | #3

   What frammer said.
   Unless you live up in the Blue's or where there is really considerable snow fall that stays on the roof for long periods of time, then higher.

   They can't get your Goat if you don't tell them where it is hidden.
1. 
   davidmeiland | Aug 29, 2008 08:16pm | #4

   Are you guys saying buy 36" wide material (like I&WS or Glacier Guard) and cut it down to 24"?

1. 
   dovetail97128 | Aug 29, 2008 08:19pm | #5

   The actual applied width of the material would be dependent on the size of the overhang.
   Key is how far up the roof from the plate line .
   They can't get your Goat if you don't tell them where it is hidden.

1. 
   davidmeiland | Aug 29, 2008 09:09pm | #7

   Gotcha. We don't do that here, it's all 30# felt all day every day.

1. 
   dovetail97128 | Aug 29, 2008 09:22pm | #8

   Don't do it here either, but I understand the concept and the need for it from growing up in Ohio and all the posting on the matter here.
   See all the time I spend here has some small benefit!

   Edited 8/29/2008 2:23 pm by dovetail97128

2. 
   frammer52 | Aug 29, 2008 10:09pm | #9

   I actually had 2 rows installed on my roof!  Ice dams, don't you know!

3. 
   Marson | Aug 30, 2008 12:35am | #10

   We don't over analyze it. We just run two rows. I believe our local code require 3' inside the building.

2. 
   seeyou | Aug 29, 2008 08:40pm | #6

   The diagram I've seen shows the I&WS to be installed at least 24" measured on a horizontal line beyond the inside wall plane.

   http://www.querycat.com/faq/79776683cf3254d8309dcc74aa906a62View Image

4. 
   DanH | Aug 30, 2008 12:46am | #11

   Understand that ice dams tend to occur at the point in the roof more or less directly above the building wall, regardless of the amount of overhang. You need to install the membrane beyond that point, and upwards high enough so that backed-up water won't overtop the membrane. The distance is going to depend on the slope of the roof -- you need to go farther on a shallow slope to get the same vertical elevation.

   Of course, proper attention to insulation and ventillation can go a long way towards preventing ice dams, though there are situations where they're hard to avoid.

   In science it often happens that scientists say, "You know that's a really good argument; my position is mistaken," and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion. --Carl Sagan
1. 
   frammer52 | Aug 30, 2008 01:07am | #12

   you aren't kidding dan!

   I have retro insulated my house every time I do something, then I find another area I missed.  I just should have tore out all the plaster and started over.