2 year old Dibiten roof with leak - what next?

Sorry for the length of the several posts - lots of photos (and I can provide more if desired), and I wanted to give the history.

I have a house with a complex roof, that I had completely re-roofed 2 years ago: Main house has a (shingled) gambrel roof with dormers, dining room and garage (shingled) more-or-less L shaped gable roof at the end of the gambrel portion and extending back past it, 3-season addition nestled in the crotch between the gable roof and the gambrel roof and extending even further to the back with a flat roof, and then two (flat) patio covers. One patio cover is L-shaped and attached to the fascia of the flat-roofed addition and to a ledger board on the back of the dining room below the gable end. The other is attached to the fascia board at the eave of the dining room roof. The covered front porch is about 2:12 slope and treated as a flat roof.

The flat roofs (addition, patio covers) are maybe 1:10 or 1:12 slope, and done with torch-down Dibiten 4 I think, 1 layer with base sheet and cap sheet with white slate flakes; there is a second layer of smooth around the perimeter of the addition roof. I think the drip edge is the same stuff they used on the shingled part of the roof. The roofing material for the patio covers extends up the fascia up to the underside of the drip edge all around.

I live in southern California (San Diego County, a little bit inland but still get cool breezes thanks to the ocean), so moderate weather year-round but lots of sun especially in the summer, and little rain. You can get away with a lot here, because when it rains, even if there is a leak there is usually an opportunity for everything to dry out before it rains again.

Anyway, it took about a year before I started noticing a wet spot on the back patio behind the addition, and as it has been raining off and on for the past 2 1/2 weeks, I finally got to observe the leak in action. Let me post some pictures of the flat roofs and then I’ll post again with a description of what we’ve found in the way of leaking.

This is the back of the house, before the re-roof. You can see man door to the garage on the left under the side patio cover, sliding door to the dining room under the back patio cover, gambrel roof with old patch, windows on the addition under the flat roof (it has a fireplace in the corner), and all the junk on our patios.

Also before the re-roof, showing the other end of the back patio cover and the corner of the addition.

Garage, dining room, and side patio cover, in progress (back patio in the foreground with base sheet only):

Back patio cover, in progress:

Addition, in progress, with back patio cover in foreground:

On the whole, I think they did a better job of workmanship on the shingled parts of the roof than on the torchdown portions.

The father of the father-and-son team kept on “forgetting” to bring the replacement shiplap board to replace one that was damaged on the addition near the corner with the chimney, and they ended up having to lift up the roofing they had already applied, in order to replace the wood. They also ended up with a 1.5" wide strip of ungranulated cap sheet where the lowest and next-to-lowest rows overlap, after moving the sheet around to install the wood. They did add more flakes to it, but it didn’t stick as well. Mainly, I’m not sure how thick the sheet is there.

OK, so here are some shots of the leak:




What I could see was water streaming down that inside corner where the patio cover meets the addition; the roofing material was disadhered from the fascia at the end (I thought water was going in there, but in hindsight I think it might have been coming out), and the OSB in the corner was quite wet. About 3 feet in, at the junction of the fascia and patio cover, water is dripping from the 2x2 patio cover lattice-pole and from the rafter below it.

Rebeccah

First thought was that the water coming down that inside corner was getting in between the roofing and the fascia board, or under the roofing through the 1/8" gap between the lower drip edge and the fascia.

Other corners with the same detailing didn’t have the problem, though. The father of the team thought there wasn’t enough coverage of the drip edge and the fascia with the roofing material, and sprayed primer on the fascia and added a small patch:



It didn’t solve the problem, though. Less water running down the inside corner with the next rain, but I got a nice video of the dripping from the rafter, and more droplet staining of the lattice pole nearby (I don’t know if I can post video, but here are a couple more photos):

So, father and son came back again, and this time the son found an area where the roofing material was not well adhered to the drip edge where two pieces of drip edge overlap near the low point of the sagging roof of the addition (all of my roofs sag). It was drizzling, so the roof was wet, and they knew they couldn’t do anything definitive about it, but they did heat up the loose edge, try to dry it out as well as they could with the propane torch, spray more sealant, and stick it back down again. The plan is to come back later when the roof is dry and apply a patch.

Today it was sunny, so I went up on the roof and looked around and took some more pictures. I found another drip edge overlap spot where the roofing material appears loose:



The spot that they heated and re-adhered seems pretty well stuck for the moment.

Also, that 1 1/2" strip between the first and second rows of cap sheet doesn’t really seem to cover the drip edge well:




I suppose these cracks are probably normal?

Rebeccah

So, now what exactly is my question?

Well, I guess the real question is, what would you recommend at this point?

  • Should I just keep after them on the patching?
  • Is the drip edge the right kind, and if not, should they pull it all out and redo it? Let me go find a photo with the drip edge before they covered it up…
  • Should the whole flat roof (on the addition, at least) be redone, given the questionable first-second row overlap?
  • Should I consider putting another layer on top?
  • Should I have another company come out and assess?

Thanks for any input.

Rebeccah

The drip edge goes on top of the roofing membrane then it get stripped in .

The leaking is definitely where the torch down does not adhere and completely cover the eve-drip metal.

The metal itself is incorrect.
The top flange should have its own overhang before it drops down to the 90 degree angle.
Its also installed improperly.
They didnt know how to fasten it down properly.

I also always put a starter strip.
The starter strip is upside down torch-down material
that i cut into strips. 8 inch or even 6 5/8 wide strips.
This is
Installed after the base sheet and before the perimeter metal.(eve-drip)
This sandwiches the metal perfectly
Its not possible for water to run back under the metal and get back in.

They didnt know to completely cover the eve-drip.
The side laps( 3 foot laps, the rakes)
Should over hang the eve metal because
It shrinks back away from it in the future and causes this problem.
I try to overhang my side laps over the eve metal approx 1/2 inch.

It sounds like you are very reasonable and have a good relationship with this roofer.
But i am angry looking at these photos
The only way to fix it as it sits
Is to burn an 8 inch strip all the way around the perimeter. Let it overhang about 1/2 inch.

Honestly, this installer is just not that smart…
First he burns the material an inch back from the edge.
Then when he goes to fix it, he overhangs it about 2 inches.
I would be so mad i would want to fight.

He shouldnt have took on this job.
He had very little experience with this.
I wouldnt want him repairing all this.
He doesnt know what to do
He didnt see the problem to begin with,
So he wouldnt be proficient in properly solving it.



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It is acceptable to di it a done here sandwiched between the base sheet and cap sheet. Although I wouldn’t do so with a nailed base like this.

Seems to me they looked up how this was supposed to go and didn’t know how to actually do it.

The starter strip you do is not a standard detail with any commercial roof manufacturer for their 20-40 year warranties, and the fastening in the drip edge is fine except he used nails which can back out vs screws. You want staggered fasteners on a 3" flange for your drip. Also T-drip or drips with an overhang are almost never used on commercial flat roofs.

They seemed to know what to do just did a poor job. The drip edge should not have a raised edge, they were way too stingy with with the asphalt primer, which is part of the issue. The raised parts are where the drip is overlapped and they didn’t angle cut the flange or lock the drip together properly. When you have a gravel stop like this you also must use SBS Caulking on the edge of the sheet against the metal, bleed out is not enough.

They dog eared the corners like they should, biggest issue is the exposed selvage edge. This means you have little to no lap on some of these sheets.

My best guess on the cause of the leaks from the pictures is the poor priming of the metal has some edges not adhered and the raised drip is forcing water back in and it is running down the nails. This is one of the reason a lot of drip edges are set in mastic. Most likely the leak is on the upper part and running down into that corner getting between the drip and the nailed base.

Your fix would work regardless in this case if we are right.

Other option is to have the roofer get some one part liquid flashing from Firestone and put that down over the exposed selvage edges and the leaking area with embedded polyester, then embed granules before it dries. Use an SBS caulk to seal the drip edges and see if that stops the leaks. The laps should also be probed in that area to make sure water isn’t getting in a lap too.

1 Like

When Home Depot starting selling Torch applied Modified, every carpenter, painter, plumber, landscaper, sheetrocker…became a professional installer…
…almost forgot, the guy at the drive thru and the bank teller…

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Thanks, roof_lover. Let’s see if I get it:

I seem to remember reading the metal for torchdown drip edge needs to be thicker and steel rather than aluminum for heat stability, and pre-primed for the asphalt to stick to it, is that right?

I had told them a couple of times that I didn’t want the vertical portion of the drip edge flush with the fascia when we were discussing the shingled portion of the roof. It was my understanding the drip edge should overhang about 1/4" and this helps limit capillary action/wicking from the bottom of the drip edge. The job took longer than planned and had a lot of complications, and at some point my attention/energy flagged and I started getting very selective about what I nagged them about.

I had thought they were going to do this. Now that I look at the photos I took, it’s clear they didn’t.

Sigh.

So this would just be added on top of everything that is there now, the way that little patch is? It doesn’t matter if the perimeter is higher than the field?

I spent a lot of time interviewing roofers for this job. Between the steep gambrel roof, the flat roof, the patio covers that I didn’t want to have to completely rebuild, my questions about ventilation, and my desire for metal valleys (very unpopular among roofers here in San Diego county), it was tough to get one that I thought could do a reasonable job for a reasonable cost, and I had time pressure because I wanted to install solar panels while I could still get the 30% Federal tax credit. I wanted a permit pulled, and I knew (and was correct) that the entire deck of the shingled roof was going to have to be replaced, so it ended up being an expensive roof - nearly $30,000, and the flat roof portions fell short of my expectations anyway.

So, you would recommend I hire a different company to burn an 8" strip around the perimeter, overhanging 1/2"?

Thanks again,

Rebeccah

Thanks, Dtris.

Not sure what typical differences are between commercial and residential construction. What is T-drip? A 30-40 year commercial quality roof for my 3-season room and patio covers would not have been in budget.

[quote]
They seemed to know what to do just did a poor job. The drip edge should not have a raised edge, they were way too stingy with with the asphalt primer, which is part of the issue. The raised parts are where the drip is overlapped and they didn’t angle cut the flange or lock the drip together properly. When you have a gravel stop like this you also must use SBS Caulking on the edge of the sheet against the metal, bleed out is not enough.
/[quote]
They had a spray they used on the fascia board and also a tube of black sealant - which are you referring to when you talk about “asphalt primer”?

What direction should the flange of the drip edge have been angled? More overlap at the edge, or more overlap toward the middle of the roof tapering to little or none at the edge? How are you supposed to lock the overlapping drip edge together?

What do you mean by, “when you have a gravel stop like this”?

What is “SBS” caulk?

This is the same concern I had about that 1 1/2" strip with inadequate gravel. is this worth putting a whole second layer over? Is that even feasible?

[quote]
My best guess on the cause of the leaks from the pictures is the poor priming of the metal has some edges not adhered and the raised drip is forcing water back in and it is running down the nails. This is one of the reason a lot of drip edges are set in mastic. Most likely the leak is on the upper part and running down into that corner getting between the drip and the nailed base.

Your fix would work regardless in this case if we are right.

[quote]
Does “your” fix mean roof_lover’s fix of 8" strip around the perimeter?

By “exposed selvage edges” I assume you mean the black stripes along each lap of the Dibiten cap sheet, including the 1 1/2" one and the 1/4" to 1/2" ones?

I don’t know that I would trust that embedding polyester in liquid flashing and then embedding granules before it dries is in the repertoire of these roofers.

Rebeccah

Aaaaaaaaaaaaaaaaaaaaaaaaaa

Thanks again, roof_lover. I’ve made online requests for inspections/quotes from two companies. One has replied, and will be out here on the 24th.