Trying to make sense of this roofing project I’ve got approaching. It’s above a mudroom, has been leaking for a while as you can see, very low pitch. I’m thinking this probably should have had a rubber roof on there but it seems like they just shingled in layers of asphalt to create a slight pitch or something? My plan was to add OSB sheathing and then apply a rubber roof but then I realized it doesn’t really look easy to tie-in the shingles from the shed dormer and the rest of the roof, the small valley portion.
This will be my first official DIY on the roof. Last summer I spent some time fixing leaks on the other side of the house, removing shingles, laying ice and water shield, felt paper, and replacement shingles, but this is less straightforward and getting into more building science that I’m not as familiar with.
I may be totally wrong about the “flatness” under those shingles and end up finding a structure built completely different, but that I won’t know until I tear off the shingles. Received advice to tear off the drywall in the room below and get a look at the pitch of the ceiling joists-Probably do that first. The rest of the roof has shiplap sheathing so I’m guessing I should expect it here as well.
If anyone can offer some suggestions it would be much appreciated. If it’s a better idea just to go with shingles again I’ll just make sure I’ve got plenty of ice/water shield under there etc, I’m open to that as well but just wondering if that’s what is called for here.
What I keep contemplating is whether the decking should look something like he photo with the lines, with a metal channel between red and blue running off the corner and into the gutter? If that’s the case, how do I tie-in the rubber portion of the roof to the shingles? Or does that mean stick with shingles?
On another forum it was advised that the window sill is probably too low (will have to be replaced because of rot.) Is it possible removing the shingles by the window will reveal a space that will put the edge of the flat roof in line with the rest of the roof? Any flattening of the roof would definitely call for rubber wouldn’t it? Water has to be directed away from that window and too those corners I think.
That’s what I’m not clear on. Does any of this make sense the way I’m asking it?
Thanks in advance.