A heavier shingle doesn't necessarily make a better shingle.
Many years ago roofing contractors would compare shingles by weight, the heavier the shingle the better. Lighter shingles were always the lower quality shingle that would not last.
Most shingle manufactures don’t even list weights today. Weight is no longer a factor when choosing a shingle.
Today 95% of the shingles are made with a fiberglass matt. Fiberglass is much better at withstanding the elements. These tough fibers make up the base material to form a stronger, lighter, thinner product. The newer products have a much longer life span. Fiberglass shingles have a “Class A” fire rating and will not burn. Fiberglass will not absorb water either, keeping the product light weight.
Manufacturers use quality high grade asphalt on the top of the shingles. In the past, asphalt was applied to the top and bottom of the shingles.,wasting a lot of the asphalt underneath the shingles where it did nothing for the effectiveness of the shingle.
Using less filler in the asphalt and high quality limestone results in more protection from severe weather. Less fillers contribute to a thinner better shingle.
Adhesive strips help lock shingles in place allowing for higher wind warranties. The adhesive on the back of the shingles seal the shingle down and prevent it from blowing off in strong winds and storms. Better products hold shingles in high wind without being thick and balky.
For a nice finish we use colorful mineral granuals to reflect the sun's rays. These come in a large variety of vibrant colors so you can choose beautiful shingles that enhance the beauty of your home and, most importantly, they last a long time.