I have architectural shingles. I noticed on a few of them that the some of the lower portions of the top layer of the shingle are loose, as shown.
What is this condition called? If I search for delamination, I get results about the seal between two different shingles failing.
Should I just re-adhere with roofing tar/adhesive? You can see where the original adhesive was at the bottom and mid-points of the shingle. Any other thoughts?
Its delaminating like you said. The shingle is made of two mats that are adhered together giving the shingle its dimension. This is a manufacturer defect and more commonly happens on steep or Mansard roofs. You can try and make a claim with the manufacturer if you know what kind of shingles you have.
Best thing is get a couple tubes of roof cement and put a dab under any loose spots so they don't end up sliding on you.
It doesn't come fully attached. The black line at the bottom is an asphalt strip that is sticky when hot, the sun heats it and it sticks the pieces together.
This is a bit of a special case because of where the shingle is located and thus the smaller size and odd shape and that is why the problem happened here. And at the bottom so water flow down the valley is greatest here
Clean out the dirt and put some roofing asphalt between them especially on the right side where the valley is located so water won't be forced under when running down the valley and all will be well
It’s called “self sealing” shingles (or lack thereof).
Shingles are made to self seal to each other by having the sun heat them up (including the asphalt strip on the underside) and the weight of the shingle will cause the asphalt to press into the lower shingle.
When the shingle is hung at more than about 6:12 or in a cool environment, then the weight does not affect the shingle and it does not stick to the lower shingle.
Often “hand tabbing” is required. Hand tabbing is merely “hand applying” a glob of asphalt about the size of a quarter to the lower shingle about every 12” on center and then stepping on the upper shingle to squish it flat.
Without the shingles sticking together, they are susceptible to “blow off” in high wind areas.
In your case, use a single glob for the small shingle. Do not coat the entire area, because the shingle will heat up from the sun and need to move and expand.
It was probably installed in cold weather. Being in a valley it most likely sperated when the installer pushed it in to valley. When was roof installed
It appears the layer of shingle material adhered at the factory is coming apart. Use roofing tar or even roof caulking which is also an adhesive. Watch out for this continuing to happen as it may require replacement under the manufacturers warranty.
You should be able to make a claim if its several pieces sounds like the lamination never did its job to stick to the other part of the shingle. Could be due to the way it was made from the company its worth the shot to make the claim.
That tab appears to have been lifted by the roof covering installer to place a nail underneath it, possibly due to it being near an intersection of slopes. Normally a nail would not have gone under the upper tab of a laminated (dimensional) shingle. That nail should have gone THROUGH the tab being lifted in the photo, and within the "nail line" area a few inches up the slope, where the shingle above would have concealed it.
