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daluu 11-06-2012 09:17 PM

Roof patch job ok or not?
Thought I'd get some input on this. I recently did some patch jobs on my roof. Was wondering if it should be ok for short term or if it needs more work, or I should get a roofer to fix up issues instead.

Trying to get by on the problem areas for a few years before reroof when fix all issues together, since current shingles still have a few years of life left and don't want to pay for interim repairs unless needed.

I did patch job using Henry's 208R SBS Rubber Modified Wet Patch Roof Cement combined with reinforcing fabric.

I used it to patch 4 problem areas:
  • warped weatherhead flashing that's not flush with roof pitch
  • pipe flashing gap where trimmed to meet valley flashing
  • pipe flashing trimmed and intersecting valley flashing and secured with exposed screws
  • exposed roofing nails on shingles here and there

See photos for reference.

For warped weatherhead flashing, I decided not to replace flashing and surrounding shingles myself or hire a roofer to do it (one quoted around $375 to fix that). One roofer I consulted for reroof quote and to look at my roof also suggested I could patch the problem areas like the weatherhead, which is the advice I took. You could say I probably did crappy patch job with a mix of acrylic caulk, foam gap filler, concrete crack filler to fill up gaps, then cover and seal with the roof cement + reinforcing fabric. Or should I have use roof cement all the way as gap filler as well?

Here's the weatherhead before photo

Weatherhead after photo

unfortunately, I did notice some absorbed water during one rainy day shortly after I patched. will see how it fares after more rain comes. here's pic of that event:

the pipe flashing patchin seems ok so far I think but wanted feedback, here's a before photo. Sorry didn't take good close ups of the before here. see the pipe flashings nearest the valley flashing:

here's the after photos

If the patching, or some of it will work. How long do you think it will last before I have to repatch (before I reroof a few years down the line)? I live in northern California (bay area).

joecaption 11-06-2012 09:32 PM

Want the good news or the bad news?
The good news is you did not fall off the roof.
The bad is all those repairs were done wrong.
All that gooped on tar is just going to crack, leak and make it harder for who ever has to strip that roof.
If it's the seals that have failed on the vents they sell a simple ring that just slides down over the pipe that fits tight and has a rim that's larger then the old one and will never leak.

daluu 11-06-2012 09:44 PM


Originally Posted by joecaption (Post 1046342)
Want the good news or the bad news?
The good news is you did not fall off the roof.
The bad is all those repairs were done wrong.
All that gooped on tar is just going to crack, leak and make it harder for who ever has to strip that roof.
If it's the seals that have failed on the vents they sell a simple ring that just slides down over the pipe that fits tight and has a rim that's larger then the old one and will never leak.

It's not the seal in question here (though there is related issue there). Issue is with how the pipe flashing on the roof/shingle side (not the pipe side) meets valley flashing. The installer didn't do good job of sealing it. They at one point sealed it with some roof sealant. That type dries up hard and can crack. They only put minimal amount to seal along the the surface where water can intrude. I patched a larger area to ensure better sealing coverage. Not sure how the cement I use changes over time, but right now still rubbery rather than dry hard. I do notice that where the material being sealed is non-porous, the cement will hold the water off (as standing water on top) from being absorbed into the cement or material underneath, not sure about if porous material underneath.

I did consider problem of removing screws on flashing where I cover with the cement so I placed painters masking tape over the screws and flashing area before applying cement so that at least the tar won't get stuck onto the screws so easily. I know this is potential issue on removing later on but fixing it well will require a removing flashings and quite a few shingles and installing properly, which quote from roofer was not cheap to do (as interim repair comparing to having to reroof later on anyways, not very cost effective).

Oh and falling off the roof, yea, lucky to be alive :yes:, but the roof was not very steep pitched (2:12 and 4:12), and only 1 story, so wasn't bad.

joecaption 11-06-2012 09:55 PM

A single bundle of shingles and a small box of 1-1/4 roof nails is all it would have cost to DIY.
This is what it was suppost to look like.

Notice no tar showing.
When sealing up an exposed screw or nail a simple small blob that gets flatened out with a cheap platic throw away putty knife would have been enough.

tinner666 11-06-2012 10:15 PM

Looks like you'll be diverting water under the collars now.

joecaption 11-06-2012 10:26 PM

This is a picture of the ring that could have been slipped over the pipe instead of all that other poop.

No tools, no mess. less then 1 min. to install.

JWilliams850 11-06-2012 10:33 PM

id say a bundle of shingles and replace those pipe boots instead of smearing bull all over them and you would have been fine.

daluu 11-07-2012 12:17 AM

thanks for input so far everyone. I think you all missed the point of my patch job. If it were that easy, I'd consider doing things differently. Sorry I didn't take detailed close ups of the before pics to show what I mean visually.

The patching was done to vent pipe flashings that intersect a valley flashing. The current ones (vent pipe flashing) were cut up to fit within the valley flashing, so it doesn't go over it, and it can't go under because it's at an angle unless one means to bend the pipe flashing to fit at an angle. One was left exposed where it was cut up, with shingles under flashing and valley flashing right in front of where it was cut up. So there's a small gap where heavy wind driven rain could force water down the pipe. The other one was also cut up such that there was overlap of some of the pipe flashing onto the valley flashing and they secured it by screwing the flashing together then applying some tar/sealant around the screws, some of which deteriorated off by now.

So if I were to replace with shingles and new flashing, pipe boots/collar, etc. I'd still have to address what to do where it meets valley flashing. Cut up again, somehow bend and fold over or under valley flashing, etc.

Two roofers who looked at my roof for reroof bid gave different approaches on how to fix that during reroof. One roofer suggested having HVAC contractor move those vent pipes farther away from valley flashing so they could be flashed properly w/o the intersection problem, otherwise he would just seal it up with sealant (or tar) kinda like how I did but looking better. The other roofer planned to hot solder the pipe flashing to the valley flashing so no screws/nails needed and no gaps exist between the flashings. But if that was done as a repair job, he quoted around $1250. And that I assume also needs removing the flashings to solder together, can't easily solder in place for DIY job.

As for the weatherhead flashing, to remove it would require cutting up the flashing or disconnecting utility service line to get the old flashing out since it's not a simple pipe that you can pull out nails and lift flashing up and off. I have yet to find a good contractor that would do that well and for good price. I don't have the experience and too much work to do myself. And I can't simply fit a new pipe boot/collar or flashing over the weatherhead either because it's not a simple pipe. By the way, I notice the weatherhead flashing is a LOT thicker (1.5 to 2x I think) than vent pipe flashing for some reason, making it harder to cut and remove.

joecaption 11-07-2012 08:56 AM

It's a really simple job if you can get to that vent pipe to move it from inside the attic. Someone really messed up on that one. Never should have been done that way in the first place.
The mast is done with a split boot. Just remove and cut the old one in half and replace.

About a 1/2 hour job.

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