Lay the second row of shingles.
First row for roof.
Set out the first second and all the rest of slates on a pitched roof.
This 1 2 tab has to be cut off where it hangs off the left edge of the gable roof.
The bottom edge of the starter and first row of shingles was damaged from hurricane harvey going through are area and i wanted to repair to keep from having.
And while this shortcut did protect the roof deck at shingle joints and cutouts it unfortunately left that first course of shingles unsealed and vulnerable to wind uplift.
These shingles are instrumental in making sure the asphalt shingles are correctly laid out on your roof.
The exposure on the first course of slates may be reduced by dropping the chalk line for the top of the second course of slates in order to increase the headlap on the starter course.
The sealant on an upside down three tab shingle ends up far too high up the roof to effectively seal the first course of the finished shingles.
If these first shingles are not installed correctly there will be problems with the entire set of shingles.
The height distance up the roof of the starter slate must be at least 3 inches greater than the vertical exposure on the first course of slate.