I put on new addition and in one section of old house there is low pitch roof (definitely under 4/12 but not sure if 3/12 or even 2/12). My addition butts up next to this area and since the roof on addtion is much higher in this location, I have an area which could easily get drifted with snow. I say that the entire low pitch roof should get weather watch paper and that the paper should extend up the wall that the roof butts up to. Then it should be step flashed. The roofer did not run weather watch up wall (I don't even know if it is on the low pitch section at all-yet?) and just step flashed. When I brought up the issue with my contractor, he said that yes, it would be good idea to put weather watch up the wall, but he is insisting that it should just go on wall and overlap the step flashing that is already there. I say that the paper should have gone under the shingles and up the wall. His way is obviouly much easier to do now! The GAF website seems to say that my way is correct. any thoughts?

next ?--where my porch roof meets my wall there is L flashing. everything I read seems to say that it should be nailed to roof deck but not the wall to allow for movement. Yet the siding guy intends to nail a J Channel through the L flashing. I couldn't find anything on certainteed site (my sidng manufacturer)to really clarify the issue. It just said the leave 3/4" to 1" space between roof and bottm of channel but I think that this would place nail through the L flashing.

Thanks
bill

 

If I saw the same illustration you did, it does not show the Weatherwatch going up the wall, although it could be done that way. Rarely does one see that type of detail in new construction or reroofing. If one wanted to apply a strip over the top of the step flashings, there would certainly not be anything wrong with that. As far as the siding nails penetrating the flashing, that's normal. The siding should be kept a good 1" or so above the shingles, the nails will be about 1" above that. If you do adhere the membrane over the top edge of the step shingles, the membrane will seal the nail holes so you would have nothing to worry about.

 

To avoid misunderstands I suggest we start referencing roofing underlayments by their classification as “Water Resident Underlayments” (WRU) or “Waterproof Shingle Underlayments” (WSU, for example Grace brand “Ice and Shield”) instead of by brand name.

1) Every shingle manufacturer I’m aware of requires the use of WSU under the entire field of a conventional composition shingle roof in low slope applications (less than 4/12).

2) Most manufactures of WSU specify that they run up the wall at confined rake edges, for example here’s that detail from the Grace Ice and Water Shield installation instructions:



- Grace Ice and Water Shield Installation Instructions

 

weather watch would be GAF brand of WSU, I believe. on the GAF web site it shows it going up a side wall slightly and on a video on their site, they specifically say that it should go up side wall and then step flash over it. Yet the roofer said that is not the way it is done, he has 23 years of roofing experience, blah, blah. I still think he is wrong and I just hope my roof doesn't leak. I think I can leave this area open for a while so that I can easily see if getting moisture in the attic space

 

on slight pitch,ice and water on all,and extend up the wall to back up the flashing for sitting snow melting,or wind driven rain purposes,covering flashing with felt is not the same,although that should also be done before the siding
if you don`t follow manufacturers specs,you have no warranty on their material----if the roof pitch is 4 on 12 or better,felt up the wall would basically accomplish the same thing,but all my jobs we run strips of ice shield at the roof/wall juncture with 3-4" turned up the wall behind the step flashing