3-Tab HIP Caps on Arch Shingles: Getting them to Lay Flat

If I use the proper nail positions on 3-tab caps, I will get terrible bedding: With arch shingles you can get a 3-ply step down along a HIP rafter and the cap nail can be on either side of that step. The result is cap tails that don’t lay down or is so low, the next shingle won’t seal on it due to the gap.

I’m thinking 3-tabs are just a bad idea…

The same issue still happens with dedicated hip and ridge shingles.
It especially happens on a thick grade architect shingle.
How i handle it is i remove the double laminate from the field shingle where i see it will lift up( not be a flat surface) for the cap shingle.

And then i also re/arrange the nail pattern also.
If you 4 nail instead of 2 nail in these particular areas, you can feel pretty confidant of no problems.

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Thanks, I was afraid each cap would have to be “fitted.”

I forgot to mention this is even more of a problem on HIP caps where there is an additional step between courses. (Ridges aren’t so bad since the most you can have is a 1-ply step.)

Trick with hip and ridge espically this time of year is take your time. Wait until the sun comes up, open the bundle and spread them out black side up to warm them up. Hold both sides and work them back and forth in an arc to get some curve bent into them rather than just bending them over the ridge. If you can put the bundle in inside overnight. Key is not to rush and you can get a good job.

Sure some guys will think I am crazy but had big grand manor job last year and took all the hips home and left them in my living room, then put in the truck as I needed then. 30 boxes at 62$ for 10’ I made sure they were dam good and pliable before installing.

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I’m also thinking DO NOT taper cut the 3-tabs - use the full width which will support the nail more and produce less “ripple.”


I’m in Phase 2 (finishing 2nd half of job this year) and have evolved some further thoughts on this:

  • Don’t cut the taper on the 3-tab caps - do this on the roof because sometimes, you’ll want what you just cut off to fill a low spot.

*This is the BIG ONE: Do the double 3-cap treatment where you expose the bottom cap 1/2in. BECAUSE you can really “cut out” the bottom cap where you have high spots. Unfortunately I started with the single cap treatment so I can’t do this one ALTHOUGH I have in really bad layouts, inserted little triangles under the cap where nailed, to build up low spots.

Whenever im finished capping,
I go back and see which cap isnt laying properly
Because of what you say.
I force it down with roofing cement in a caulking gun.
It is fast and easy.
It will never be a weak point in the future.
It will be a strong point.
And it is looking good immediately,
Not having to wait for the Sun.

And again, it is pretty easy to remove any little pieces of double laminate off the field shingles near the hip to hinder it.


The ones I cement down, I make little 180* bend clips in alum to hold them down.

Separating lam is OK on sunny 80*, but when it’s cooler (even 70*), that adhesive is a bear. (Of course cool weather is great for separating the glue down strips when trying to lift shingles. But if it’s not cool enough to crack them, oh baby, is that a mess…)

One other tip:

When the ridge rafter intersects a wall or dormer fascia, here one side of the hip caps get trimmed back at the wall, all the way down to the hip rafter centerline for the last cap. IF the last few courses of the main roof are 12" or less, use the 3-tabs instead of Archs for courses! It is virtually unnoticeable and it eliminates any double ply stackups.


The biggest trick is to “torch them down” heating the sealing strip with a propane torch and then bonding the next cap before you nail it. The hot tar strip solidifies in a few seconds and eliminates the need for the cap to lay perfectly flat so it can seal in the sun. The strength of the torch down bond is great.

Please tell us that you don’t get the torch anywhere near the ridge framing…Just what you need, a roof fire!

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Good point. I wouldn’t trust some roofers with a BIC lighter.

However I’m also an expert oxy-acetylene welder and know how to mange flames and heat. It’s easy to burn wiring, carpet, and interiors when welding on cars. Roofs are nothing compared.

I never really understood this thread from the start.

If the building is built plumb & square within reason and the hips are decently straight there should be no issue with the cap that isn’t being introduced by the installer.

If you want a good result hand nail your cap in the right place, that is all.

There certainly is no need for a torch fer chrissakes.

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If you just nail them down, no matter how you do it, some will not contact the sealing strip on the underneath shingle due to the 2 and 3 ply steps in the nailing and sealing areas.

The hip caps have an arch in them that gives them additional strength in regards to wind resistance, it is more important that they are fastened correctly.

Some cap shingles don’t have a sealing strip at all and 1 I can think of only has it on one side.

I know that if I used caps, it would have been a no brainer. But the roof was a hip with 4 big dormers - lots of caps - so I did 3-tab to save money. Even if I would have done the double 3-tab, it would probably have not been an issue. But I was trading time for money.