'Cracked' 3-tabs

Tinner I took a quick look and could not find the thread that had the pics of the leaking 3-tabs.

You were right in being surprised that knowbody seemed to care much about it. I was thinking about it today… Where was the water coming thru? Left, middle, or right? I wonder what damage is down when racking a 3-tab if the installer pulls to hard to lift the shingle to place his nail. Is it cracking the fiberglass mat in there allowing water come thru?

You said you have seen this before, were they all racked or were any of the stepped?

Maybe you missed some pages?

They weren’t cracked. Water just runs through the backs of the shingles. I don’t recall if they were racked or not. Irrelevant in this case. Every keyway allowed plenty of water through them.

A close up of the keyway.




Not really a big deal. Didn’t leak on sunny days.

Well that’s roofing for you
When it’s raining you can’t fix them
and when it’s sunny you don’t need too.

Thanks stormer and tinner. I was calling them cracked because thats the only thing that makes sense to me. Ok, so is there water running thru shingle… that is a big deal to me. I have been roofing for ten years and have only replaced a roof prematurely because of a bad install not a defective shingle.


Do you know what manufacturer made these shingles? I know you said they were fiberglass but I am very interested in finding out more info.
I can also see this was a very low slope application which does not excuse the seepage problem.

I’ve pulled afew of these off now. No visible defect. Felt wet as all get out. Big stains on the felt at each keyway.
This just happened to be the first time I had a camera ready. My phone with a removable card! Never leave home without it.

I have also tracked leaks in dimensionals to a butt joint. Several in fact. In each case, a flashlight couldn’t be seen through the shingle. Water going through though.

This is the reason I contacted the manufacturers and asked about dutch laps. Two spoke off the record and said dutch lap would be preferred, and may be the future method of choice.

I DL’d my house!

Tinner, do you have any pics of the dutch lapped roof you did? How does it look? Lumpy? How far did you lap at the shingle ends?

Lumpy is in! TRG caught the only thing I didn’t do to make it uniform. He was the only one too. And it is something I really wanted to do, but it is too time consuming already to do one that way.

If you plan one, be prepared to spend 20% more for shingles, and about 30% more time.



Be prepared for some to call you a JL too!
My roof does get me jobs by people that want a dimensional looking roof though.

Ok, so how far is the dutch? 3"? Now how to combat the water wicking a little under the field shingle’s on anything under 6/12?

Now what about those old dim shingle’s that had the factory made dutch lap. They lapped 1/2" and always a dragon tooth sticking to far out on the right and a single layer on the left. What do you think of those? I’ve never seen them new, just a few TO’s.

Well Roofer, it varied. TL used a 3/8" dutch lap when they came out. Worked fine.

I didn’t want much hump. I only lapped over single ply ends. After wrecking a few shingles, I learned to leave both ends, if necessary unnailed until I knew which way I would go. Sometimes, I tore the top piece off, and lapped the entire spot to hide the line.

Side wicking doesn’t seem to be a problem. I tried it with a hose. Squirting water under would make it drop, unimpeded onto the back of the lower shingle, where it had a 1/16"-1/8" tall channel to run out. No wicking like when it got intoa keyway or butt joint.

Here is a 2-1/2 or 3/12 I did on the GC’s house. He built it and insisted on the shingles. I used Elks, 4" exposure, 6" DL. It’s sat under 14" of snow once or twice, and weather Tropical Storm Gastone which dumped 15" in 8-9 hours. Just a layer of Tamko I&W under it, I believe. HHD nails. I drop in to see him sometimes and check it.

They were the Timberline.

BTW, For my first 30 years, I really tore into anybody DLing anything! But T-lock, Sears, and a few others had it. And in 40 years, I honestly have to say I’ve yet to find a leak caused by DL.

Slate are done that way on many jobs, and I’ve seen the specs to lay slate in the valley without any underlay, just lapped in and rolled up the sides in DL fashion. Haven’t tried it yet.

With the water wicking thing I mean on the bottom edge. It seems that the bottom-under side of the shingle is holding water when the roof is damp. Light mist today and I was installing a few bathroom vents today… When you go to pry up the shingle water runs out… I’ve only seen this on easy walkable pitchs. The water seems to run under each shingle a little just like it does on the shingle at the gutter edge… One of those things I find alarming.

Shingles have always done that. Just don’t use felt,eg, nails. They’ll be dust in 6-7 years.

I think your roof looks good. I maybe would have done an open valley with it.
This whole idea is very interesting to me. I plan to do my own roof next year maybe I will try.
About the nails, Tinner, you are about the only one I know who uses hot-dips, and I have started to use them too, only consistently on low pitches though. I have torn off lots of old roofs with no leaks with EG nails. Most of the nails had only a small amount of corrosion. Have you had or seen a lot of problems with EG nails? outside of a butt joint?

DL was fine for T-locks and 3-tabs,but IMHO not for arcs…my 2 cents

I’ve tron off too many that needed repairs and all the nail heads were rusted off. If they’re nailed right at 5 1/5", there’re going to stay wet and rot off.
Now, I just use either 1" eg or copper nails for felting.