Valley flashing

OK, so I’ve always wanted to be a flasher, and I’ve heard valleys are the best place… :shock:

But seriously. I’m re-roofing my house (was shake, will be composite shingles), and I’m to the point where I’m about to put in the valley flashings. All the information I can find refers to a valley that runs all the way up from the eaves, and that’s all very straightforward. However, I have a few areas around dormers that do not run all the way up from the eaves, but start much higher on the roof, of course. “It seems to me” that I’d want the valley flashing to empty onto shingle material, not just the felt underlayment. By that logic, it seems smarter to shingle up to (well, slightly higher than, actually) the lower edge of where the valley flashing will lie, and THEN put in the valley flashing. OR, is there some tricky way to get the shingling underneath the flashing after you’ve already secured it into place?

Hopefully I’m making sense here. I’ve got another area where a valley drains into a low-slope area, and that’s not such a big deal since I’ve already got the low-slope system in place and partway up into the higher-slope area, so there is already a place for the valley to drain, but it’s those dormer areas that have nothing but felt on them so far that I’m wondering about…

Youre right on track in your thinking. It is ok to leave a littl of the valley metal showing to promote positive waterflow.

Be sure to flash the dormer fascia, also, before installing the valley.

Good luck.

looks like deej should be given advise not gettin it.


Aw shucks, gweedo, thanx! :wink:

Seriously, I’m pretty proud of the job I’ve done so far (even though it’s taken me literally months of part-time work to get this far)! Maybe I’ll take/post some pictures so you guys can admire my work (or possibly razz me for it if I’ve done something stupid!)

Funny, I just stumbled over this post in which there was a lot of homeowner-bashing going on. I don’t think we’re all morons… :evil:

I might even end up with a better roof than some roofers would install! But to be fair, I’m reroofing because a former homeowner did some very stupid things that (no surprise) ended up leaking, causing damage, etc.

good job deej. youre very logical. with your logic, send us a picture and we’ll tell you if anything is wrong. I’d bet youre doing fine by your presentation, but it would be nice to get qualified opinions.

I just re-read that thread, and it seemed to me a lot of roofer bashing going on.

Most, if not all of the general public realize the amount of knowledge and experience involved in being a quality roofer s opposed to being an average shingler. BWDIK?

The general contractor that just did my roofing & siding job has a master’s degree in mechanical engineering and has been roofing for 15 years. He subbed out my job, but he was overseeing it. [Yet I still had to catch the fact that they sided over a bathroom exhaust vent]. I only have a BS in engineering myself.
This guy’s 6’10". He reached up to the roof and pulled off an old shingle to demonstrate they were brittle.

When I was doing mortgages, I worked with lots of people with masters degrees… SOMEONE with common sense had to help them :smiley:

Agreed Aaron, there’s bashing of both homeowners and roofers going on there.

Can’t we all just get along? :roll:

I know that when I mention to friends/co-workers, etc. that I’m re-roofing my house, I get pretty much the same reaction - a lot of respect for taking this on myself. But then again, this is in Silicon Valley, CA, and I work with a lot of techno-weenies that probably don’t even wash their own cars, let alone tackle anything like this.

Truth be told, I didn’t appreciate how much effort was involved and how long it would take. Then again, I added a few other projects “while I was at it” - it was an especially good time to re-insulate (remove nasty blown insulation and replace with wrapped fiberglass batting), drop some speaker wires down the inside of my front wall (impossible to get through the top plate if there’s a roof on), re-run the cable/antenna wires through the attic instead of tacked along the side of the house (thank you ComCast), put in a new electrical service (upgrade from a 4-fuse fusebox to breakers! Which I had done professionally - that’s outta my league, but the timing was still good for that), a few minor other patch-ups/goof fixes.

Should be much nicer when I finally finish though! :mrgreen:

And you other guys are right too - lotsa education does not a wise man make. The school of hard knocks is under-appreciated.

OK, so I have those pictures you asked for, S&G. This one shows you one of those areas I’m wondering about (yes, I know I still need to put another run of felt in the valley). I think in this case I want to put in the shingling up to just above the lower end of the valley, then put in the flashing and continue up from there, as I mentioned in my first post. Agreed?

And here is where a different valley is dumping onto the low-slope area. I’ve since decided I need to do a little extra here to prevent all the drainage from ending up in one place and wearing away the roofing - I’ll send an updated picture once I’ve got that in place.

Lastly, this one shows a very evil area. The valley ends right at the corner, which would mean any drainage would dump down the side of the rake edges. Not good. The edge metal I have in place will provide some help, but I don’t think it’ll totally handle the issue. I haven’t decided exactly how I’m going to resolve this one - any bright ideas from the experts? Maybe just a gutter extension from the eaves up to here?


Build a triangle roof. Then run the valley down onto the lower section.

So if I’m understanding you right, Lefty - you’re suggesting I put in an extra triangular-shaped section between the two rake edges and extending the valley, sorta like I have here?
Right? It might be tricky for me to get all the angles right…

If it were my project, I would like to see the fascia installed over the step flashings that go in at the eave transition, and a leader installed at the bottom of that valley, but thats just me.

Dennis could make you a nice scupper head (leader)