I recently re-roofed my porch using rolled asphalt. We had a torrential rain last night and when I looked up at the bottom of the ply wood roof sheathing (still haven’t put on the ceiling) they were all completely wet! And I mean wet, not just in one place, like totally, universally wet. So wet that water is dripping down off the rafters.
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The porch has a slight pitch (about 1/12) which is why I used rolled asphalt. I followed the instructions to a t: I nailed every 4â€, tarred up 6†on all joints, 2†on all course overlaps and tarred over all the nail heads and all joints and course over laps. I properly installed flashing and drip edge.
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I went up this morning to check it out and every thing appeared right with the roofing.
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Why/how could this be happening? Does rolled asphalt ever let water through when it’s completely drenched? What can I do to remedy this? Should I apply another layer of roofing?
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Thanks, Mischa
Replies
By "rolled asphalt", do you mean rolled asphalt roofing, or tarpaper?
Sounds like 90 lb. roll roofing to me. I'da gone with an 18" lap type myself.
wait..no I wouldn't.
I wouldnt have it at all. Rubber rules.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
"If Brains was lard, you couldn't grease much of a pan"Jed Clampitt
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rolled asphalt roofing
Well, something is odd. Even though the thing might leak eventually, it shouldn't leak right off, with all the nails and seams tarred. Could rain be getting in at the top edge and running down the bottom of the roof sheathing?
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
No, the only dry portion is the top quarter or so. Maybe I’ll go take some photos and post them…
Photos
in the pics it almost looks as though you roofed from the top down and that your seams are upside down.... maybe it is just the pics?
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I refuse to accept that there are limitations to what we can accomplish. Pete Draganic
Take life as a test and shoot for a better score each day. Matt Garcia
It's just the pics; I started at the eve and worked up the roof toward the house. The dampness you see in the pics is on the "uphill" side of the course overlap.
I suspect that the water is originating from above your new rolled roofing. The roof section above your flashing looks pretty bad in this photo, circled in red by me.
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Looks like water could get in/under that white edging material and then travel inside the overhang structure. Could also be spilling over the higher roof section, running down and under the eave (water can "hug" a wall/ceiling) and then inside your new flashing.
Pull off your new "flashing", after running the hose on the roof section above the new rolled roof. I'll bet you see water behind where your flashing is located.
.
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
Edited 8/4/2009 6:16 pm ET by PatchogPhil
That looks like built in gutter filled with dried out tar.http://www.quittintime.com/ View Image
It appears that the outer-most edge is higher than the roof inboard from it. That would "dam" a lot of water that percolates down inside the overhang and finds it's way behind the new flashing.
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
Could it be condensation? High Humidity.
upper 1/4 generally dry.TFB (Bill)
Not sure? Is that possible? Any way I could check?
I wish it could be humidity but upon sober reflection it's really just too much water; the rafters are dripping, there is water pooled on the ground below the drip.
I think a problem exists at the flashing. If rain is blown at the flashing it could get in at the creases I am seeing as well as at the screws. I would slip a counter flashing under the wood molding to cover the top of the existing flashing and coat all the screw heads that are exposed with a good caulk.
no way. The wood is dry at the upper end of the roof.
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I refuse to accept that there are limitations to what we can accomplish. Pete Draganic
Take life as a test and shoot for a better score each day. Matt Garcia
I would tend to agree with dam inspector that the vulnerable point is your flashing against the wall. Is the flashing embedded in anything or did you just lay it down on top of the roof and the wall. If so the trouble shooting would be pretty straightforward. Grab hose and work you way up the roof. If it does not leak just going directly on the roofing materials, the spray into the wall flashing. It looks like it can get under the flashing .
One of the reasons I suspect it is the flashing is from the underneath images, the wetness begins at the first plywood seam except at one rafter where it runs up higher. I would bet there is joint in the plywood.
Best of luck
Bruce
I think you have it right. I don't know how he sealed the metal to the roofing, but it is full of puckers and fishmouths top and bottom.Why would he think that if 4" oc nails is necessary on the laps, only 12" is OK on the metal?I do see another problem too tho. Gotta go baCK AND LOOK MORE AT ALL OF THEM
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Paul ,
That metal is under a 12 " overhang .
Walter
I can see that.He also said it was an extremely hard rain, but I have seen flashing like that leak in a normal rain from splashbacks. I don't know how mucch is running off from the roof aabove either or if it is bleeding down over, but I don't doubt some of the problem is at the flashing.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
It's also soaking wet.....You are always welcome at Quittintime
The top third of the roof is dry inside the OP claims
The top third of the roof is dry inside the OP claims
Water could still be getting under the asphalt rolled roof at the area and "higher". Water leaks in a roof can be hard to trace back to the point of penetration. Water could get under the top-most roof material (i.e. shingles, slate, rolled roof, thatch) at one point, then travel horizontally and then leak below the sheathing far away.
But with a name like "slateman", you probably knew that already. :-)
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
Edited 8/4/2009 8:11 pm ET by PatchogPhil
Thanks for all the great feedback!. I really appreciate it. This is our first home and this is all new to me, books only go so far and you all really fill the gap.Sounds like it is the flashing; I'll tap a few more screws in to take care of the fish mouthing best I can and slip some counter flashing in the overhang. I'll let you know if this works...
What is the detailing of that overhang? Is it a gutter? Or some kind of edging? Does it puddle with water?I'd look at that overhang as a source of the water infiltration.
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
You might have a good point about possibility of it getting in from above, but I can't see the detail well enough to agree no matter how hard I squint ;)
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Did you seat that flashing in tar or just screw it in place?Without it being sealed, water can back up under the metal on such a low pitch
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That's his description, but you can see in the photos that it is quite wet, has been wet before, and will keep getting wet until he fixes the flashing
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I think the material is cracked too and waters coming in thru the body of the roof .
I don't think it's all the flashing . If it was the plywood would be wet right at the top.
but the plywood is wet right at the topI thought I saw a crack too. Some of that stuff looked old already.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I'da got the garden hose out before I even posted about it.Spheramid Enterprises Architectural Woodworks
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"If Brains was lard, you couldn't grease much of a pan"Jed Clampitt
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I put up some counter flashing a few days back. We've had t-storms all day today and the porch is dry as a bone! Thanks again, Mischa
I have no idea how to check. May not be it, seems warm moist air condenses on cooler surface. Right now I would expect warm outside, cool inside.Just seems that a leak would be limited to an area or sheet of decking not all the way across.TFB (Bill)
Are those BOX gutters on the roof above that I see???
Mom's house had an apparent leak in an EPDM porch roof ('pro' installed, not by me)
Installers could not figure it out. Next time I went back, found a crack in box gutter just under the roofing overhang, in heavy rain the gutter would back up far enough to pour water down thru the house wall to under the epdm flashing. "top being dry' is what others have said, running on top of highest ply, then thru gap between plywood.
My solution at Mom's was to tear off the box gutters and extend the eave and install (horrors-plastic gutter - but then mom is 87yo).
this the thread you were looking for Hiker?---- enjoy!
stephen
How did you find that?
figured it was in "general discussion" or "construction Techniques" started with General discussion--scrolled down didn't find it--so hit "next 50"--and there it was gotta thank you---- I am feeling pretty smug--- it's rare I can successfully do ANYTHING with a computer----- I can't even remember how I resized pictures before posting them--- even though I did it close to 100 times a couple years ago in another thread---AND TOOK NOTES so that I would remember-- I actually wrote out a cheat sheet on an index card step by step--and saved the card in case I ever wanted to resize pictures again---and now I can't get it to work 2 years later, LOLBest wishes,
stephen
In your photos, it is so obvious that water can be getting in at the top of the flashing I won't detaail that, but I think there are other spots too.
Also, you did not mention having used any tarpaper under the rolled roofing.
In these photos I detail some pukers in the metal that appear they might be near the point where you first see water from below.
and then I detail where i think you have a crak or cut from a knife in the surface of the 90# and where I can see nail heads thru the tar indicating that might be a probelm now or become one in a year or so.
I never expect more than five years from a rolled roof like this. sometimes I get luccky and see ten
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Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Now you climb up there and clean up all that crayon scribble young man.Spheramid Enterprises Architectural Woodworks
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"If Brains was lard, you couldn't grease much of a pan"Jed Clampitt
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Mish,
Just a "stupid" diy but it looks to me like it is leaking at the top center then running down and spreading out across the roof. Look where I have an arrow pointing in the picture. Actually it looks like the sheathing has been wet there for a while, you can see the stains.
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
I was wondering how much overlap you have at the seams?
Bill