To see our Technical document with the full story, including clarifications on the life expectancy of various asphalt shingles (including the “lifetime” type)

Click Here




Weatherproofing, Sealing or Glueing Roof Shingles...

Glues Shingle Granules!

The natural weathering process of an asphalt shingle roof can be stopped

Roof shingle weathering occurs from: A) water infiltration into the asphalt, which then leaches out the oils from the asphalt, resulting in a drying out process that weakens the asphalt’s bond to the granules, B) temperature changes that result in normal shingle expansion and contraction that cause microscopic cracks in the asphalt, which will eventually loosen and dislodge the granules, and C) the winter evening freeze thaw cycles common on the Island, that also break the granules away from the asphalt base. These combine to expose the asphalt to UV rays through the loss of the protective granules. The UV rays then dramatically accelerate the weathering process, and the ultimate destruction of the shingles.

The tiny granules, which cover the asphalt on a shingle, do not weather: they are ceramic covered stones, which can last a lifetime when kept sealed or glued in place on the shingle. 

Thanks to our technology we can stop the weathering process on the roof by simply coating or glueing the shingle with our clear acrylic spray-on shingle protectant. Dr. Shields Canadian Roof Armor stops water infiltration into the asphalt, and bonds the granules to the shingle. It is now apparent that this procedure will at least double the expected lifespan of a shingle or torch on roof. Instead of a shingle roof lasting up to 20 years on average, when weatherproofed, we now expect 40 to 50 years. We have doubled our original 5 year warranty to our new 10 year warranty covering the durability of our customers roof shingles. This has obvious cost saving benefits, and greatly reduces our carbon footprint by not sending old roofs to the landfill.

Weatherproof (Seal) your roof with "Dr. Shields Canadian Roof Armor" and you’ll add years, and save thousands. Exclusive to Vancouver Island, Gulf Islands & the Lower Mainland, Canadian Roof Armor stops granule loss in its tracks. With over 1,000 sealed roofs, BBB (“A+”) accreditation, and a 10-year guarantee … Now 6 years of shingle weatherproofing behind us, we have gone back to inspect the shingles on the roofs that we weatherproofed 5 years ago using "Dr. Shields Canadian roof Armor" and are pleased to announce; we have found no breaking down in the roof shingles or degradation of the roof sealer. You can trust The Great Canadian Roof Doctor to add years to the life of your shingle tile or torch-on roof. 

So, Don’t Re-Roof, Weatherproof!

“Weathering” is a general term used to describe the effects on shingles of long-term exposure to the elements.

Weathered shingles aren't necessarily damaged shingles, although weathering will eventually damage shingles past their functioning point. Weathering is a natural process that causes shingles to deteriorate over time. The rate at which shingles weather can be affected by a number of things such as the following:

Shingle Quality

Low-quality shingles will fail before high-quality shingles. Quality can vary widely among manufacturers, and even within a single manufacturer’s product line.

Structure Orientation

South-facing roof slopes have shorter lifespans due to increased thermal cycling and UV exposure. Some portions of the roof are affected by prevailing winds more than others.

Degree of Roof Slope

Flatter roofs have shorter lifespans because they shed moisture more slowly and are more directly exposed to UV radiation than roofs with steeper pitches.


Harsh climates shorten roof lifespans. Wind, moisture and thermal cycling all contribute to deterioration of roofing materials.

Thermal Cycling

Climates with large daily temperature swings shorten roof lifespans because they cause greater amounts of expansion and contraction. This increases the roof’s rate of deterioration.

Roof Color

Darker roofs absorb more heat, which shortens shingle lifespan by accelerating the loss of volatiles and increasing thermal cycling.


Homes at higher elevations are exposed to more UV radiation, which deteriorates most roof-covering materials, including asphalt shingles.

Roof Structure Ventilation

Poor ventilation of the roof structure shortens shingle lifespan by failing to keep shingles cool, resulting in accelerated loss of volatiles and greater amounts of thermal cycling.

Quality of Maintenance

Failure to repair damage and keep roofs clean can result in damage and deterioration from moisture intrusion and wind.


Asphalt Shingle Lifespan

Asphalt shingle lifespan is strongly affected by weathering. Even though the rate at which shingles weather varies, they still go through a generally predictable lifecycle.

The lifespan of asphalt shingles is related to the rate at which they deteriorate. The long-term deterioration pattern of an asphalt shingle can be broken into three parts:

Incipient deterioration

Accelerating deterioration

Decelerating deterioration

Incipient deterioration is the first stage. During the incipient stage, deterioration takes place very slowly.

As time passes, deterioration starts to worsen, and shingles enter a period of accelerating deterioration.

By the time the deterioration curve begins to flatten out and the decelerating period begins, the shingles have reached the point of functional failure.
They’re no longer protecting the roof and are trying hard to turn back into the raw materials from which they’re manufactured. 

All this can be stopped by simply weatherproofing the shingle with Dr. Shields Canadian Roof Armor. 



Let’s examine the life-cycle of asphalt shingles from the time of manufacture onward.


Shingles start to age and deteriorate as soon as they’re packaged. This is the beginning of the incipient stage. The deterioration process is very slow at first, and is mostly driven by oxidation, the chemical processes taking place within the asphalt, and sometimes also by heat and pressure, depending on storage and transportation conditions.


Deterioration accelerates dramatically once the shingles are installed and exposed to weather. The asphalt layer is new and hasn’t yet had a chance to cure, so this rapid aging continues for a short time until the asphalt layer becomes tougher. This period typically includes minor granule loss as excess granules adhered during manufacturing separate from the shingles and are washed away by runoff.

 Slow, Prolonged Aging

Once the curing period is complete, shingles enter a long period of aging at an ever-increasing rate.
At first, the pace will be so slow that it won’t really be visible. Deterioration starts on a very minute scale with micro-cracks in the asphalt, the loss of a few granules, dissipating volatiles, and chemical changes in the asphalt.

The rate at which aging increases depends on a number of factors, such as shingle quality, roof orientation, slope, and other factors. This is the end of the incipient period and the beginning of the accelerating slope.

 Accelerating Deterioration

During accelerating deterioration, these factors become more important. Multiple factors can combine to drastically extend or shorten the service life of the shingles.

As they approach the end of the accelerating-deterioration slope, all shingles will have common failures that aid in the breaking down of the shingle properties back to their natural organic state. 


Weatherproofing saves (roof) lives! 

When the shingles are caught in time before they reach the curling, cupping or cracking stage, you can save their lives by weatherproofing them with our exclusive clear acrylic spray-on shingle protectant. Do it yourself or have us do it for you. 


RX: Prepare shingle roof surface for weatherproofing (sealing) first clean by removing all moss dirt and algae, using a low pressure directed water spray. Next, apply "Dr. Shields Canadian Roof Armor,” to the exposed area, to rejuvenate, beautify & protect shingles from weathering, granule loss, and the drying out process of the asphalt, this application will greatly extend the lifespan of roof shingles.