Nesting each new row below an existing one keeps the new nails 2 inches below the existing which will help minimize any splitting of the sheathing.
How to re roof with architectural shingles.
After that correctly positionthe first shingle and properly snap a line of chalk across the roof to mark the top layer of the shingles.
51 to 124 per roofing square shingles are priced per roofing square which is equal to 100 square feet.
Attach each shingle with three nails one in the center and one each on each side.
Architectural shingles are durable less prone to curling and hide imperfections better.
Apply a cover of starter architectural shingles.
Architectural roofs should be able to and withstand more damage than 3 tab shingles.
Best solution is tearing off the old shingles first.
Instead of one layer laminated or architectural shingles have two or more layers with three dimensional tabs of varying sizes.
You can cut the layered edge of architectural roof shingles and use the cut flat piece as your starter roof single.
While both types are made up of the same essential components re roofing over architectural shingle is a different case altogether.
Use galvanized roofing nails long enough to fully penetrate the sheathing typically 1 1 2 inches for a second roof and 1 3 4 inches for a third.
The professional answer is no you should not attempt to re roof architectural shingles over existing architectural shingles.
Apply the first real course of architectural shingles so that the tabs reach the lower edge of the starter course.
The standard practice is to limit to a total of two layers of shingles.
Mark a chalk on subsequent roof layers upward.
After that you should tear off old shingles before installing a new layer.