Architectural vs 3 Tab Shingles

As both a home inspector and a semi-nerd, I always like to collect and analyze data. One benefit of this is that I can identify trends and look for anomalies during an inspection. For example, the most common plumbing DWV (drain, waste & vent) system I see is scientifically known as (C8H8·C4H6·C3H3N)n, better known as Acrylonitrile Butadiene Styrene(ABS) which looks like hard, black plastic pipe. Over 95% of the homes I have inspected contain some amount of ABS. It’s not just a plumbing material either: did you know that all Lego blocks are made of ABS? You can see a small bit of this pipe sticking out of the roof on almost all homes when looking from the street, so this statistic doesn’t surprise me.
 
Probably the second most common thing I see is asphalt roofing shingles and like ABS pipe it provides the best combination of quality and value. Again, probably 95% of the homes I inspect use asphalt shingles, although this number will drop in the future as metal roofs are becoming more popular. There are two types of asphalt shingles: organic and fiberglass, with most now using fiberglass as organic shingles were generally not made after 2006 and completely discontinued in 2011.
 
Now let's take a look at the two major types of asphalt shingles for residential roofs: 3-tab and architectural. I have not begun to track shingle style yet but both are common in Nova Scotia.

 3 Tab Shingles
They are so named because they have three tabs on the bottom part of the shingle. They have a flat, uniform design and look like the picture below. The main advantage of 3 tab is that they are lightweight and generally more affordable.

Architectural Shingles
These can also be known as dimensional shingles and are thicker, being composed of a more random, textural look that can look more like other materials such as slate. Typically these shingles are more durable and last longer but with the disadvantage of a higher initial cost. In my experience, most homes (my own included) use this type of shingles. 

3 Tab Shingles

Architectural Shingles

It's Not Quite THAT Simple
There are also various grades of shingles available on the market. Unfortunately, determining the grade of shingle is beyond the ability of a home inspector but it is important to note there is no such thing as "bad" shingles. I always like to joke how every company has a "good, better and best" but never "crappy, less crappy and mediocre". In this case, the former is a good representation of the products on the market and a quality installation is far more important to a long lasting, leak free roof. ​