# roofing a dormer



## steve1234 (Sep 13, 2007)

As part of our remodel we raised our peaked entry way. The result is a dormer style roof that meets the main roof. My question is regarding the sequence for the roof installation, especially regarding the small triangular shaped section under the dormer roof eve where the dormer roof meets the main roof. 

1) should the shingles of the main roof be pulled back, then the plywood of the entry gable installed to contact the plywood of the main roof (along the valley line), all before installing any new roofing material, or 
2) does the main roof get finished to where the entry walls come up through the main roof, then the plywood installed on the entry cable such that the plywood sits on the roofing material of the main roof (along the lower part of the valley formed by the dormer eve)? All followed by the valley flashing. 

Thanks to Ed's comments in a previous post, I believe I have the valley flashing and everything else figured out. That small triangel area has me puzzled. Also I will be sealing the wall in that hard to reach section with the ice / water seal, flashing, felt, and stucco prior to setting the last piece of entry roof plywood.


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## Ed the Roofer (Jan 27, 2007)

Steve,

This is the 3rd time today that I read your post and I want to make sure I answer it correctly for you, so if you could please attach some photos of the various details, I might be able to help out.

Ed


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## steve1234 (Sep 13, 2007)

Thanks Ed. I will take some photos this afternoon and post.


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## steve1234 (Sep 13, 2007)

Ed-
See attached pics. 

What is the proper sequence of installation to get the roofing along the main roof to the wall coming up through the roof (especially into that small corner under the eve) as well as into the lower part of the valley formed by the gable roof eve. Note that the gable roof decking piece that makes the eve is just tacked on and easily removable to roof, flash and stucco the wall. 

Oh and try to keep the laughter to a minimum regarding the gutter installation......left over from the old roof line and obviously there is some work to be done there. Also the paper in the pic is part of the temp cover and I know it need to run horizontally.


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## Ed the Roofer (Jan 27, 2007)

I will reply in detail later this evening.

Stop before you go any further though.. The advise will save you constant future leaks.

(Chuckle - Chuckle -.....Hey guys! Did you notice that gutter) Just kidding.

Ed


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## Ed the Roofer (Jan 27, 2007)

Okay, I just got back from my last apointment.

First, remove the bottom row of plywood decking on both sides of the new dormer.

Second, remove the shingles that abutt the side wall of the dormer including the courses which go up to and slightly past the nottom of the valley..

Third, Install at least an 12" wide strip of Grace Ice and Water Shield splitting the differnce with 6" on the main house roof deck and the other 6" going up the walls of the dormer sides.

Fourth, Install the shingle along the bottom below the shingles if need be. Have a piece of Apron Roof To Wall Angled sheet metal counter flashing fabricated or bought at the roofing supply house nearby, and allow it to span at least 3" past both sides of the walls on the left and the right. Take your tin snips and trim the bottom of those 3" + pieces that go past the corners. Cut the bottum on an appropriate angle so that the sheet metal flaps can make the bend around the corners without being inhibited by the slope of the decking on the main house roof. Bend them and nail them to the side walls.

Fifth, when installing the new shingles, secure on 5" baby tin step flashing for each successive course of shingles. The bottom of the baby tin flashing should line up with the bottom of the shingle.

Do all of the shingling under the new dormers soffit overhangs before replacing the bottom row of plywood decking. Then reinstall the decking.

Install the felt paper and the gutter apron drip edge metal flashing and the gable sides overhanging drip edge flashings and then it is ready to be shingled.

Now shingle the dormer and make sure the shingles from the dormer go past the center of the valley at least 12" and do not nail the shingles any where near the middle of the valley.

Maybe I will add more with an edit after looking at the photos again.

You also need to tear off the shingles from the main house roof where it meets the dormer valleys. 

Prior to installing the felt paper and the new shingles, make sure that you also install a 3 foot wide piece of Grace Ice and Water Shield in the valley and overlap the top of the valleys so there is no unprotected spots remaining.

The main house roofs shingles will be the ones that go on top of the shingles which passed the center of the valley and then these will need to be trimmed. Snap a chalk line in the valley. At the bottom of the valley, go 2" away from the center of the valley and line up the chalk line 1" away from the center of the valley for the top measurement.

Ed


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## Ron6519 (Mar 28, 2007)

One of the problems you're having is that you didn't set out the end points on the main roof where the gable roof joists were to hit the roof. From what I see, you wanted a valley on either side of the gable. The first thing to have done was lay 1x8's or 10's down on the roof flat to the eaves in the shape of an "^". The ridge board would hit the top of the ^ and all the gable rafters would be sitting on the 1x's from the top to the eaves. This guarantees a straight, continuous valley on both sides. This requires you to cut compound angle cuts on the bottoms of the joists, where it hits the roof. These need to sit dead flat on these boards for this to be a structurally sound addition. 
This is a structure with alot of angle cuts that need to meet up with another piece of wood. From what I see, you need the help of someone with framing experience who can "see " the finished product. This sort looks like someone winging it. Not a good idea.
Ron


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## steve1234 (Sep 13, 2007)

Ed-
thanks so much for the reply. That's what I was looking for. I already picked up the roll of ice/water shield (surprised at the $$). I think I got it all, and it makes sense. 

Another question, the pics show the last sheet of dormer plywood sitting on the main roof decking. It seems that this angle should be cut such that the decking doesn't actually sit right on the main roof shingles. True or does it not matter that much since the valley will cover the decking and extend a bit over the edge such that the edge of the dormer decking it completely up underneath the valley? 

Again, Ed, thanks for the info......


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## steve1234 (Sep 13, 2007)

Ron 
Thanks for the input. I'm not sure I completely visualize what you're saying, but......

this is part of a complete interior remodel. We have re-framed just about every wall in the house. The framing is the only thing we hire out. The framing crew we had has a very strong reputation and has worked with one of the top custom home builders in the Bay Area.....maybe more info than required. Anyway..... there is a gable roof ridge beam that runs to the gable "V". The are flat 2x's that run along the valleys. The valleys are actually "straighter" than how they look in the picture.

You mention the main roof point don't line up with where the gable roof rafters hit the main roof. The valley used to end where the last gable rafter hit the main roof. After everything was framed there was a need to cut the gable roof rafters back (the way they were "didn't look right" according to the interior designer (wife)). So when the rafters were cut back that moved the point where the edge of the gable roof meets the main roof farther up the main roof. The way the roof angles lay out, there is not enough room to get another gable rafter in from the wall to the point where the gable roof meets the main roof.

The stucture is quite sound. Maybe a few more pic might help illustrate what was done. 

Please understand I'm not trying to dismiss what you are saying, quite the opposite. I want to understand if there are any shortcomings and get them fixed, but I'm not sure I've clearly communicated everything that has been done. I will post up more pics


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## Ron6519 (Mar 28, 2007)

The picture I see has the last lighter colored ply at a different angle hitting the roof then the ply further up the valley.
If your plan was to have a wall coming up rather then the gable dormer hitting the roof line all the way down to the eaves, you can ignore that part of the post.
To flash this properly you would need to install step flashing where the old roof hits the gable wall. The framers should have cut back the roof shingles about a 1/4" away from the wall so the flashing could get set. You slide the flashing up under the shingle so it doesn't stick out and nail it to the wall(one nail, at the top). Work your way up the shingle row until you get to the top row. 
Ron


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## Ed the Roofer (Jan 27, 2007)

steve1234 said:


> Another question, the pics show the last sheet of dormer plywood sitting on the main roof decking. *It seems that this angle should be cut such that the decking doesn't actually sit right on the main roof shingles.* True or does it not matter that much since the valley will cover the decking and extend a bit over the edge such that the edge of the dormer decking it completely up underneath the valley?
> 
> Again, Ed, thanks for the info......


That needs to be as tight to the main house decking as possible.

That is why you have to remove the shingles on the main house roof for about 3 feet away from the valley.

Then you shingle the dormer roof and then the main house roof over the dormer shingles.

Ed


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## the roofing god (Aug 2, 2007)

weird style gutter ???,and why isn`t the valley in a straight line ???


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## Ed the Roofer (Jan 27, 2007)

steve1234 said:


> Oh and try to keep the laughter to a minimum regarding the gutter installation......left over from the old roof line and obviously there is some work to be done there.
> 
> quote]
> 
> ...


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## Ron6519 (Mar 28, 2007)

Ed the roofer said:
"You woud be well served for cosmetic and funstional purposes to re-cut your valley decking so that it is a straight line from top to bottom, without a hook in it."
Unfortuneately you can't just cut the ply. When you do, the plywood will be about 6" off the roof if you continue the present angle down. The initial "V" angle installed on the roof is not compatible with the roof pitch(too low). To fix this you would need to repitch(increase) the roof or increase the "V" angle.
That's why this statement by the OP didn't make sense:
"The framing crew we had has a very strong reputation and has worked with one of the top custom home builders in the Bay Area."
This looks like a homeowner installed handywork, not professionals that do it for a living. There is a direct relationship between the roof pitch and the intersecting gable angle. If they're not in sync, you get the pictured result.
Ron


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## the roofing god (Aug 2, 2007)

oh and I said that was a weird gutter style,not installation,I laughed quietly to myself about that as requested


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## steve1234 (Sep 13, 2007)

looking back at the picture, I can see why you think the valley is not straight. It is the angle of the picture and the tarp. It is actually pretty darn straight and the deck ply is pretty tight. I'll post up a picture later. 

As for the gutter style, I posted up a pic in project showcase that shows some "interior details" of the house. It was originally a trailer and there was some "non-conventional" building techniques used throughout the house. The gutters are just one thing on the long list. They will be changed along with most things in the house. Thanks for the comments.


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## Ed the Roofer (Jan 27, 2007)

Yes, please do post another picture of that valley looking in direct line to the valley angle going up.

It sure does not look like talented workmanship, using those two small scrap pieces on the bottom of the visible side.

Also, it surely does look like the valley takes a hook and travels straight up vertically on the next two vertical shingle slot lines just above the appearance of that hook affect.

I forgot that you had said you used a professional framer, and figured you had done that, so I was initially cutting some slack on the cuts.

Ed


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## the roofing god (Aug 2, 2007)

looking from the 2nd pic,you can see the bottom ply propped on the roof,not on the plane of the valley,and not on 2x6 runners as Ron rightly suggested they be on,it really doesn`t look professional the way it is done ,sorry :no:


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## Ed the Roofer (Jan 27, 2007)

Another thing, now that we are picking this workmanship apart, is that the ridge of the dormer roof does not look to be horizontal.

It may just be the angle of the camera when the photo was taken, but if you put a level on the top of the dormer ridge, you can find out for sure. :whistling2: 

Ed


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## the roofing god (Aug 2, 2007)

ON THE OTHER POST ,YOU SAY YOU WERE INSTALLING THE ROOF RAFTERS,AND WERE CONCERNED W/ VALLEY FLASHING,NOW YOU SAY YOU HAD A QUALITY CO. DO IT SINCE IT CAN`T BE BOTH ,WHICH IS THE REAL STORY??:detective: :icon_rolleyes:


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## steve1234 (Sep 13, 2007)

Wow, tough crowd out there....:huh: . My apologies as I was asking for some DIY tips, however I was not aware that a complete project profile was required, but here goes......

I am doing a complete remodel to our house. The condition of the house prior to the project start is a long story, but the key point is the scope of the project was very un-predictable from a framing standpoint. As mentioned we hired a framing crew that we knew well from work on our previous house as well as recommendations from construction pro's. For budget reasons, I am doing most of the work on the house. 

I had a framing budget that I needed to hit and was able and willing to complete the framing that couldn't be completed within that budget. My preference was to have a good percentage of the framing completed by a good framer rather than have it all completed by someone not so good. For better or worse, I am quite confident in my ability and skills and I knew what part of the framing I could finish and what part I did not want to tackle. The framer's schedule was such that he had a 4-week window for our project which we figured was about right. We talked everyday and he gave me my punch list of things he needed, done, moved, or changed in order to keep his guys on track. When it came to the entry way, they cut the roof and framed the new dormer walls up, framed the dormer, and put the decking down, except for the last L-shaped piece on the dormer. A small part of this L-shaped piece forms the last length of the valley. The framer said they deck all dormers like that to allow that last piece of deck to be installed after the roof material is installed up to the dormer wall and the dormer wall is finished. Otherwise, the other trades (aka: me) are trying to work under the dormer eve up into that small corner under the end of the valley. Don't know if this is right, wrong, or typical, but I put my trust in the framer I hired. 

In weeks 3 and 4 of the framing, the framer and I were always talking about the priority of things making sure they got done what I couldn't. At the completion of the 4 weeks, the lead framer and I spent time walking the job and noting the things that needed to be completed. We talked in detail about the last cut for the decking. I am now at the point of finishing the roof. I cut the last piece of the dormer decking that forms the dormer eve. 

I had been reading this board for a while and it seemed you roofing guys were knowledgeable and helpful so I thought I would put the question out to the pro's on the proper sequence of finishing the roof, as I am going to be the one doing it. In my list of personal contacts in the construction biz, I do not know a roofer. Ed's early response was exactly what I looking for. 

I'm not trying to mis-represent the work as mine or the framers, make stuff up, or hide any of my errors. I'm acutally just trying to finish my house. If I screw something up, I have no problem posting up and telling the internet world "hey, look what I did..." because I will probably learn something in the process. 

Just to clarify issues in this post: the picture was taken from a 2nd story window that was above and behind the dormer, I believe that angle makes things look a bit different than they are. The original cut in the roof was a large rectagle so the framer did add a piece of decking on the main roof that fits to the dormer decking. A very small corner of this can be seen under the tarp in the picture. The dormer ridge being level: I haven't checked it, but I will since you mentioned it, Ed. This was done by our framer. I also have not yet checked all of his headers throughout the house for level, but maybe I should. The valley, looks straight to me when viewed sighting along the valley. FRAMER OR HOMEOWNER, WHICH ONE IS IT BECAUSE IT CAN'T BE BOTH.....hopefully I explained that above. Again, my apologies if I did not describe something accurately; that was not my intention.

As for the constructive advise provided, that is still greatly appreciated, as is going easy on me for the gutters (which have since been taken off the house).


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## Ed the Roofer (Jan 27, 2007)

So, even if it out of level, I have seen that on several homes. If anybody asks, tell them that is the look you were going for.

Ed


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