July 2018 Blog



Haag’s 4/09 Shingle Gauge™ and 1/12 Shingle Gauge™ have very similar names.  And they do look an awful lot alike.  Both have a basic shape similar to a piano tuning fork, each with a central opening where users slide an asphalt composition shingle to estimate its thickness.  However, just as the basic two-prong shape of the gauges does not indicate that they can be used to tune pianos, the similar shape of the two gauges does not mean that they measure the same products.  If you have ever heard a co-worker or contact in the field refer to the Haag Shingle Gauges as “interchangeable” or as two sizes (one ‘’long”, one ‘’short”) of the same tool, it is important to know that the two Shingle Gauges are completely different and that ONE SHOULD NEVER BE USED IN PLACE OF THE OTHER.

But why?


First Came the 4/09 Shingle Gauge

Haag’s IAS-accredited Research/Testing lab has been monitoring the shingle manufacturing industry for over 20 years.  We saw a genuine need for a tool which could estimate the thickness of asphalt composition shingles and link that thickness to a warranty level.  Our aim was to support industry pros with measurements in the field so they can better prepare their roof repair and replacement estimates.

The very earliest version of the Haag Shingle Gauge, released in 1993, was shaped more like a key than a tuning fork.  As shingle manufacturers updated their products (effectively changing their thickness and corresponding warranty levels), Haag’s Research/Testing engineers continued to update this early key-shaped Shingle Gauge with slight re-designs in 2004 and 2006.

The first major re-design of the tool came in 2009, when the Haag 4/09 Shingle Gauge™ was released in its present two-pronged shape.  Haag engineers measured hundreds of shingles throughout 2008 and found that warranty-measurement estimates could be correlated for these shingle types:

  • 3-Tab Fiberglass (20-, 25-, 30-, and 40-year)
  • 3-Tab Organic (20-, 25-, and 30-year)
  • Laminated (30-, 35-, 40-, and 50-year)


Second Came the 1/12 Shingle Gauge

For several years, the 4/09 Shingle Gauge continued to accurately represent estimates on each new batch of shingles that was manufactured in the US.  However, 2011 was an important one for shingle manufacturers.  Most US makers of asphalt composition shingles changed their from-the-factory warranties, offering limited lifetime warranties on all products rather than warranties spaced in 5- to 10-year increments.  Haag’s Research/Testing division quickly went to work to determine if the dimensions used on the 4/09 Shingle Gauge remained useful on shingles manufactured after January 2011.

After studying hundreds of brand-new shingles from over 30 different manufacturers, Haag engineers realized that while the 4/09 Shingle Gauge™ remained accurate on pre-2011 shingles (of which there are still many installed on roofs today), an entirely new tool was needed to estimate warranties on all newly-manufactured shingles.  Thus, the 1/12 Shingle Gauge was born.

The “1/12” in the name refers to the newest version’s date of release (January 2012 vs. the earlier release of the 4/09 Shingle Gauge in April of 2009).  It was released after a year of urgent research, as Haag engineers studied the changes in the industry and implemented them into a brand-new tool.  Most important, the Haag team realized that the thicknesses of shingles provided by various manufacturers starting in 2011 no longer fit into as many measureable categories as pre-2011 shingles.  Unlike the 4/09 Shingle Gauge, the 1/12 Shingle Gauge™ may be used to estimate a single type of asphalt shingle:

  • 3-Tab Fiberglass (20-, 25-, 30-, 35-year and Lifetime)


Why Can’t I Use the Gauges Interchangeably?

Simply put, you can’t use the 4/09 Shingle Gauge and 1/12 Shingle Gauge™ interchangeably because the incremental widening of each tool’s slot is actually quite different.  The slot thickness may not look different to your naked eye, but remember:  the tool was designed with specified tolerances to measure what you can’t see with your eyes!  Though the 4/09 Shingle Gauge™ cannot estimate accurately what the 1/12 Shingle Gauge™ can, and vice versa, the inability of each tool to estimate certain shingles is not a failing of the gauges themselves.  Instead, it is merely a reflection of how drastically the shingle manufacturing industry changed its products in 2011.


 Scott Morrison, P.E., Director of Haag Research/Testing lab

Scott Morrison specializes in Structural Evaluations, Foundations, Earthborne and Airborne Vibrations, Roofing Systems, Reconstruction Monitoring and Analysis, Research/Testing, and Architectural.  He is a primary author of material in the Haag Certified Inspector courses and many of the Haag Damage Assessment Field Guides.  See his profile here.