Best way to flash this roof to wall intersection?

[HerHusband]

I am in the process of rebuilding a section of my in-laws 100 year old house. Originally, the back of the house was an open porch which was "closed in" at some point with a hodge-podge of scrap windows and boards.

The porch area was severely rotten, so we tore it all out and reframed. Of course, the existing house dips and leans in various directions, so we had to try to make the best compromise between plumb walls and meeting up with the old work.

To make the process even more difficult, there is an old carport (closed in at some point in the past) right in front of the back wall. This really made it hard to tear out the old work and get the new walls in place. It's not pretty, but we managed. I still have some work to do, but for now I sheathed over the two new window openings until the windows arrive.

The carport is not physically connected to the house, even though there's only a couple inches between them. Obviously, without support on the open end, the carport has racked to the side about 4 inches. At some point the carport will have to be rebuilt, but that's a future project outside the scope of this work.

So, I'm trying to figure out the best way to flash the intersection of the house and carport. My main concern is keeping water out of the house, which I can accomplish by just continuing the siding behind the end of the carport. But, I don't really want water coming in at the gap between the two buildings either.

I don't know how stable the carport is. It may continue racking in the future, or it may have leaned as far as it's going to. But, I don't want to compromise the new work by tying into an uncertain carport.

My in-laws had a new roof put on a couple of years ago, and the roofers just covered the top of the carport step flashing with a board and caulked the top where it attached to the wall. While I'm not crazy about that approach, I can't really think of a better option.

What would you do?

Thanks,

Anthony

[jloomis]

I wouldn't connect them if you have future plans for tearing out the old carport..... Why do all this nice work, and flash it to a carport that is going south?

[HerHusband]

John,

That's the catch, "I" don't have any plans to rebuild the carport. In fact, I doubt current setbacks would allow it to be rebuilt in the same location anyway.

In other words, the carport may be standing (leaning) as-is for another 20 years, and I'd like to keep the gap relatively dry.

I have no idea if it's still moving, only the evidence it has moved in the past. It's been there at least 25 years that I know of, and I never knew it was leaning till I put a level on it last week.

New work is SO much easier than this remodeling stuff... :)

Anthony

[jloomis]

[Wayne Whitney]

Structural issues of the carport aside, the conventional solution, I believe, is to run the building paper on the side wall over the step flashing from the carport roof, and then to run your siding over the building paper. Both the building paper and the siding are kept back

1" or so from the corner of the step flashing. Also, I believe the bottom step flashing should be a kick-out flashing.

Cheers, Wayne

[HerHusband]

I'll have to think about it. I considered trying to straighten up the carport, but the other side of the roof is attached in places (poorly), there is wiring running between the two buildings, and there's a limited headroom situation on the inside where the back door steps down to the carport. Not to mention the current roof flashing is a good inch or two away from the new wall. I don't know if there's enough flex to fit it under the siding without messing with the new roof. Will have to wait and investigate more when I'm on site next weekend.

I can see the carport quickly turning into a big job I don't want to get into.

I'm just an overzealous amateur, but we built our own garage, house, and a few sheds. I'm used to keeping everything level and plumb, being able to make nice square walls and tilt them up, etc. So it's a whole new experience for me trying to build new walls in a crooked house, jacking things up and hoping they don't come crashing down on us, dealing with dirt, rot, etc. :) I have a lot of respect for folks who do that kind of work for a living...

On the other hand, when I see the original work and subsequent remodels, I feel pretty good about the work I'm doing. :) It's like they pieced together the house with whatever scraps they could find. The kitchen wall we just opened, for instance, is a jumbled collection of two foot long studs criss-crossing every direction.

Weird. Joist spacings are all over the place too (14", 16", 10", 21", etc...) The most impressive thing about the old work is the size of the large beams (8"x8"x 40'), and all the joists are 24' long spanning the entire width of the house (full 2" wide rough cut lumber). When we remodeled the bathroom a couple of years ago, I envisioned how big and tough plumbers must have been back then. That old bathtub had to weigh

500 pounds, and the cast iron piping wasn't much better. I had it pretty easy with a steel tub and plastic pipe. :)

Sounds nice. We had an old shed we were going to tear down after we built our house, but I decided to unbolt it from the slab, jack it up, and dragged it around to the back of the house. We poured a new slab underneath, bolted it back down, added a shed roof on the end for firewood storage, and a new coat of paint and shingles. Looks like new now, like it had always been there. It was a good feeling knowing we were able to reuse it rather than just adding to the landfill.

Thanks,

Anthony

[HerHusband]

Thanks Wayne! I've been studying techniques for flashing roof to wall intersections and your recommendations agree with everything I've read.

Take care,

Anthony

[Wayne Whitney]

That actually looks to me as if originally there were two window openings that extended closer to the floor, and then it was remodeled to be one wide window opening higher up. That would explain the pattern of the studs.

Cheers, Wayne

[Wayne Whitney]

I thought straightening the car port would eliminate that gap? I definitely encourage you to get the car port sorted and firmly attached to the house, although I can see how that might be more than you want to tackle.

If you don't want to deal with the car port, you could fashion a large piece of Z-shaped counterflashing that would attach to the wall and extend over the roof step flashing. The lower leg would be exposed, and the upper leg would tuck under the building paper and siding. [Note Z-shaped means an offset with two 90 bends degrees, not the >90 degree bends in an actual Z.]

Cheers, Wayne

[HerHusband]

I didn't really check if the carport leans away from the house, but it leans to one side about 4".

I will keep that in mind when I check things out this weekend, though I wonder if I could just use a piece of straight flashing nailed to the wall and extend down to overlap the step flashing of the roof? It would slope outward slightly, but in the grand scheme of things that wouldn't be a huge problem. I could cover most of it with the siding so it wouldn't be so obvious.

We were really tired when we finished up last week, so I'm mostly going from memory and photos taken from a distance.

Thanks for the ideas!

Anthony

[HerHusband]

I do believe there was a different window on the right at some point, as the siding had been patched in that area as well.

The one on the left is a little weird though. No signs from the siding it had been modified, and why would the window opening have been filled with a stack of studs instead of full height studs like the right side. One of those little things that keeps you guessing... :)

Anthony

[Wayne Whitney]

The one on the left looks like there had been two windows there (of different heights) before the current window.

Cheers, Wayne

[Wayne Whitney]

Well, my thoughts are that the way to go really depends on the nature of the gap. If the gap is permanent, and won't change or shift if you ever straighten or reinforce the car port, then you can go with a permanent solution. I would install a filler board between the wall sheathing and the roof step flashing, nail each step flashing to the filler board at the top, and then install a Z counter-flashing.

But if the gap is a result of the carport's settlement, then I would think you'd want to preserve the option to straighten the car port at some point in the future without redoing too much of your current work. In that case the straight flashing seems like a good solution, although I don't know how well you'd be able to flatten it should the gap be removed by future work on the car port.

Hope this helps.

Cheers, Wayne

[Cwatters]

The car port roof already has soakers fitted (soakers are what we in the UK call the upstands in this photo

I would probably..

1) Fix up the car port so it's not moving.

2) Fix an L shape strip of lead or similar flashing to the house over the existing soakers on the carport roof. The vertical part of the L should be around 6" (150mm). The horizontal part around 2" but not critical as the soakers form the seal. Only nail through the top of the vertical part of the L not through the soakers.

3) Fix weatherboards to the house down over the lead (I believe you call weatherboard "siding").

[HerHusband]

Maybe I'm picturing this wrong, but wouldn't Z-flashing create a "gutter" of sorts?

I know this is common for deck ledgers, between plywood sections on walls, and whatnot, but those are level. Since this is on a slope I would think any water running down the wall would hit the Z, and run down along the top of the Z to the bottom of the roof. Then I'd have to devise a "kickout" of some sort to keep the water from funneling behind the siding.

In contrast, a straight flashing (even if sloping away from the wall slightly) should let water drain directly off the wall onto the roof. Though I'd still have to take care of the detail at the bottom, maybe tucking the bottom row of siding "behind" the flashing, so any water at that point would be directed out.

Am I missing something?

Yes, thanks, I appreciate the feedback and advice.

Take care,

Anthony

[Wayne Whitney]

Yes, you're absolutely right, so it would require its own kickout flashing, which would tuck under the high leg. The bottom-most piece of step flashing also should be replaced with a kickout flashing, as you have the same gutter effect there.

The instructions I used to fabricate kickout flashings can be found at this web site: . They are talking about stucco siding, but the principle is independent of the type of siding.

If the side-wall/roof gap is permanent, then an alternative to the Z-flashing is to redo the roof step flashing so that the upper legs are against the house. It would be fine to have a small exposed "valley" on the roof against the house, so you wouldn't have to change the roof shingles at all. It shouldn't be too hard, once you remove the existing flashing, which is nailed to the roof deck. You would just slide each piece of step flashing under the row of shingles, and nail it to side wall only.

Just a disclaimer: I've only actually had to do this once, most of my understanding is theoretical.

BTW, it is also a good idea to have a horizontal joint in the building paper at the height of the kickout flashing, with the lower piece of building paper going behind the kickout flashing, and the upper piece going over the kickout flashing.

Cheers, Wayne

[HerHusband]

Wayne,

Thanks for the link! I was looking into a premanufactured kickout flashing like this:

But I haven't seen them locally, and don't really want to wait around for shipping. Making my own would be preferable, considering it's likely a one time task.

Hmm... Something to consider. Thanks.

Anthony

[Cabot]

This is harder for me to write, than to just show you! 8-(

There's no need to buy a diverter. You didn't say if you have a brake handy. For a diverter, you _can_ get by without one, a brake will give you a cleaner look. Assuming no brake, take a piece of step (5x7"?), measure or eye 2 or 3", tin snip the bottom (horizontal) leg of the "L" almost to the vertical leg. Simply fold so the uncut part of the L, is almost to a 90. The cut leg will slip _under_ the other bottom leg. You may have to trim some off, depending on how far you fold it. You then trim the actual diverter on an angle, you only need 2-3" on the height, which will show at the highest point. 3/4" on the lowest point of angle.

Without telling you about how I would do it. It doesn't sound like you want to get into reworking shingles, felt up the wall etc. So I'll stick with the counter flashing.

This is where a brake is almost a must. If you are going to have a piece of coil on the wall, with no crimps or bends, it will be flimsy.

I would cut a 6 or 8" strip assuming you're using 24" coil, probably do them in manageable lengths of 4 or 5 ft. Do a slight bend towards wall, 1" down from top, so when you tack it to _wall_ not through step, it will hug the wall. On the bottom which is near roofline, a _slight_ bend _outwards_ from wall, at another 1". Keep the counter off roof, just lay an old piece of 1x material on the roof, this will keep you off the roof 3/4". You won't have to be fussing with a tape measure this way. Once your counter is tacked in place, remove the 1"x material. If you do the counter in shorter pieces, just be sure to start @ gutter edge & work up, overlapping the counter 2" at seams.

The bends will give you a clean appearance, without wavy material. Of course you probably know that.

[PeterD]

great shot, I like that leaning 2x4 on the left!

Where is the floor, right at the bottom?

[HerHusband]

And the short diagonal 2x4. I wonder what structural support that was supposed to provide? :)

Yes, just below the bottom white siding board that is still on the wall in the photo.

Anthony