Flashing and siding - porch roof to wall

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Old 08-18-16, 06:08 PM
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Flashing and siding - porch roof to wall

Hello,

Had to tear off and replace a porch on an 1890's era house. Hired out the new porch construction with the agreement I'd handle the cedar siding and porch trim work.

Been using sites like Wood Siding Flashing Details at Joints & Corners and Improper Roof and Side Wall Flashing as a guide but there's some things I'm not clear on.

How should the siding be attached where the drip edge and fascia butt against the sheathing? Should the drip edge be trimmed back a bit so the siding can slide behind and butt against the fascia?

Should the bottom piece of step flashing be removed and replaced with kick out flashing? I can make my own using guides posted here. Not sure how best to handle drainage in this area.

Is a 1.5 inch gap between shingles and siding okay? Was going to use a 2x4 laid on the shingles as a spacing guide when installing the siding.

Was going to use 4" butyl flashing tape along the top half of the step flashing and secure it to the sheathing but I don't know how well it would attach to the old wood. Is there a better way?

Thanks for any advice.

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Old 08-18-16, 06:49 PM
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There should be a piece of self adhered flashing covering the fascia/sheathing joint (and under all the step flashing). Use a kickout, but don't remove that last piece of step flashing...in fact, I would have liked to see it run down farther so it will be over the missing rubber flashing.

Trim back the drip edge to allow the siding to run fairly tight to the corner (over the missing rubber flashing).

I don't see any rain and snow membrane over the drip edge...
 
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Old 08-18-16, 06:54 PM
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There should have been a step flashing vertically behind the fascia and on top of the clapboard siding. (Fascia would need to be about 1/2" shorter, leaving space for the clapboard). Similarly, the last step flashing on the roof needs to lay on top of the siding then the next row of siding covers it.

1 1/2 clearance is good. Some guys will clip the point of the siding (the portion of the point that is hidden behind the next row) so that it angles up and away at a steeper pitch. This helps prevent rain, snow and ice from getting on top of the siding if it happens to follow that cut edge.
 
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Old 08-18-16, 07:06 PM
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Forgot to mention: the rubber flashing manufacturers will recommend using a primer to ensure good adhesion on difficult substrates. Usually it's some type of spray adhesive, but use what your brand recommends.
 
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Old 08-18-16, 07:09 PM
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I hope it's OK to reference an article at a different site. This open (i.e., you don't need to have a membership to see) article contains helpful pictures and advice:
Kickout Flashing: How to Flash Troublesome Roof-to-Wall Intersections
 
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Old 08-18-16, 07:20 PM
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Good techniques that will protect the sheathing. But its also good to prevent water from getting behind the siding at the same time. The copper flashing shown in step 5/6 of SturdyNail's link needs to be loose enough so that a piece of siding can be slipped behind it. Otherwise water will get behind the siding. The giant kickout diverter in that link is nice but it looks like a giant pain in the neck to side around and creates problems of its own. IMO, slipping the siding behind the fascia flashing, then slipping the next course of siding behind the first roof step flashing has always been sufficient.
 
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Old 08-18-16, 08:53 PM
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CarbideTipped: sounds like some rubber flashing that could've been installed wasn't. I'll probably remove one or two rows of the siding that runs right below the fascia. Maybe I can slip some housewrap behind the fascia and somewhat behind the bottom piece of step flashing. I could add some rubber flashing at the fascia-sheathing joint, and if that top staple was pulled, rubber flashing behind it as well?

I'll see if I can add a piece of kick out flashing on top of that step flashing, but underneath the flashing next row up.

XSleeper: I was thinking of using an oscillating multi-tool to shorten the fascia by a 1/2 inch but maybe that would complicate things. Thanks for the idea of clipping the siding point. To make siding around the kick out easier maybe I could do like this guy Improper Roof and Side Wall Flashing and make the kick out height the same as the gap between roof and siding. Some guides show what looks like a slit made in the siding so a full height kick out can slip through, but I don't know if my skills are up to getting all those measurements to work out.

SturdyNail: Thanks for the link. I was looking at this one too Roofs - Kick-Out Flashing | Best Practices Manual | Hammer & Hand | Pacific NW Builder and it looks like a lot of what could have been done would be pretty hard to retrofit at this point.

This is turning out to be a heck of a lot more complicated than I first thought.
 
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Old 08-24-16, 08:03 PM
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Got a bit further but don't know how to proceed. The kick out, 8" and 6" siding pieces are just test fit. The step flashing is still there. It can be lifted some but can't be removed without damaging the roof. Idea is to run flashing tape from the drip edge's top and onto the siding, then cover that with aluminum flashing that's attached to the sheathing and overlapping the siding.

I was going to mimic what A Concord Carpenter did in the other picture, reduce the kick out height so it's the same height as the roof to siding gap, then continue the angle onto the siding. Looks like that would leave a lot more flashing exposed on mine compared to his. Sorry the pencil line on the step flashing is hard to see, it is continued onto the 8" clapboard.

How would you guys handle this? Is there a better way? My neighbor thinks I'm overthinking things because other porches around here don't have kick outs. They're all aluminum or vinyl siding and look fine on the outside.

Also, do you have any preferred way to cut angles past 45 degrees into cedar clapboards? My manual miter saw can't do it.Name:  3a.jpg
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Old 08-24-16, 08:10 PM
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When using a kickout flashing, you have to make a single saw cut in the siding so that it slips down over the tall vertical part of the kickout, then that gets caulked on both sides.

do you have any preferred way to cut angles past 45 degrees into cedar clapboards
Use a skilsaw.
 
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Old 08-25-16, 06:02 PM
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Few more pieces test fitted. Maybe I'll re-cut one or the other of the siding pieces around the kick out so there's not so much of a gap. Thanks for mentioning the slit in the siding, it should make a more waterproof joint.

Do you think galvanized kick out flashing will hold up, or should I use something else? I have some aluminum 8x8 step flashing but it's pretty flimsy.

Is there a preferred flashing for behind siding butt joints? My plan was to staple 4" unpeeled flashing tape behind the joint and overlapped onto the siding below.

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Old 08-25-16, 06:09 PM
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#30 felt...........................

You may want your gutter apron to be a little more loose. You have to get the gutter + the brackets behind there and making it tight is just making it hard on yourself.
 
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Old 08-25-16, 07:13 PM
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Ok, I'll try to find some felt. Looks like it only comes in big rolls.

You know, I hadn't thought about how the gutter would attach. It was going to be next year's project.
 
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Old 08-25-16, 07:20 PM
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You could also use Tyvek if you have any left.
 
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Old 09-03-16, 04:57 PM
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Just want to check back to make sure I'm doing this right, and that there won't be any leaks. Really hoping I'm not screwing this up. Will snow build up along there and get in?

I've got two rows of 4" butyl peel and stick flashing attached to the primed wood sheathing, overlapped to each other and over the step flashing. I would have used 6 inch or taller but I read butyl may adhere better, and no stores carry butyl taller than 4" here. Maybe I should have ordered some 9" Grace Vycor. Total height is about 8" up the wall, then overlapped by house wrap.

Guess I'm worried that the how-to guides online assume that I'd have peel and stick membrane running from the roof sheathing and way up the wall, instead of just flashing tape overlapping the step flashing.

Also does the angle of that kick out flashing look okay? Will that create any ice dams? I think there's only tar paper over the OSB and not anything like ice and water shield.

Got this nagging feeling I'm making some mistake.Name:  a1.jpg
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Old 09-03-16, 05:16 PM
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Ideally you would have had at least 3 feet of ice and water shield on the roof deck before the shingles; too late now and there are millions of roofs out there that don't have it.

Ice dams happen when snow melts high on the roof where it tends to be warmer and runs down to the lower section where it tends to be colder. It then freezes overnight, and the cycle starts again the next day until the ice builds up thicker and thicker.

Good attic insulation and especially ventilation helps because it minimizes warming of the upper section of roof due to heat rising inside the attic. But ice damming can happen even in well insulated and ventilated roofs due to warming from the sun, especially when the temp is just around freezing.

The kickout won't do anything to make ice dams worse. And snow against the side wall won't be a problem while it's still snow. When it melts, the water will run down the side wall and onto the roof, so that shouldn't be a problem either.

Sometimes you get wind blown snow up behind the siding, which can be a problem when it melts; but that rarely happens unless the siding is not installed well.

I don't see any reason to lose sleep over what you've done, it's better than a lot of roof and siding jobs out there.
 
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Old 09-03-16, 06:22 PM
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Thanks. I do appreciate your explaining how weather and building materials act upon each other. It's often hard for me as an amateur homeowner to wade through this information, then form a clear idea of how things should work.

The clapboards are nailed to studs when possible. They feel firmly attached, but I can feel small gaps where they overlap each other over the step flashing. Not sure if anything can be done about that.

Is there anything I should do ventilation-wise underneath the porch roof? It does not have the soffit boards or beadboard ceiling in yet.

Guess I want to be sure it's done right the first time is because nailing those clapboards on seems like a one shot deal; the new growth cedar is hard to remove without breaking it.
 
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Old 09-04-16, 08:57 AM
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Here's a couple pictures of how I tried to make the roof to siding transition. Not shown is the step flashing behind the kickout, it overlaps that aluminum sheet and will hopefully flow water over instead of behind it. With the kickout it would be nice if water didn't even get that far.

That part is one where I couldn't find any real clear pictures of how to get the flashing to run over the siding. How do you guys do it?
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