Roofing Shingles Replacement Comparison
Getting What You Pay For When You Re-Roof Your Home

How to Install Shingles - Part 3 | Homeowners Guide to a Shingle Re Roof Replacement

The following article is Part 3 of a 5 Part Series from our of roofing articles library titled, "A Homeowners Guide to Shingle Roof Replacement".

The staff at General Roofing Systems Canada regularly contribute to our roofing article library with knowledge they gain day to day in the field. To request articles online for specific roofing informational requirements
contact us here.

Click for our shingle installation specifications. Or for a detailed look at "How to Install a Shingle Roof" properly with detailed explanations, photos, and videos from the shingle installers on the roof, visit our shingle installers roofing blog.

Roof Shingle Installations. Alberta, Saskatchewan, British Columbia, Manitoba, Ontario. Calgary, Edmonton, Red Deer, Lethbridge, Medicine Hat, Lloydminster, Fort McMurray, Saskatoon, Regina, Canmore, Cranbrook, Kelowna, Vancouver, Whistler, Winnipeg, Toronto and points between.


Introduction to Comparing Roof Shingles

Comparing roofing shingles is much more involved than just simply comparing the roof shingles themselves.

The way your shingle roof is installed is very easily more important than the shingle material used, so comparing the way shingles are installed and comparing the shingle installers is very important - as is comparing the roof shingles and materials that go in to doing a proper shingle re roof.

There are many ways to short a shingle roof installation, many shingle installers don’t even know they are installing the shingles to an inferior specification, and of course some folks just don’t want to put in the extra work required to shingle a re roof to the highest and best standard.

Or some shingle installers don't know that failing to inspect the attic space prior to installing your new shingles could easily be cheating you the home-owner out of up to 50% of the new shingle re-roof lifespan otherwise available if your attic space was functioning properly before they began installing your new roofing shingles.

Installing a shingled roof to the GRS Installation Standard does cost a little more. It does takes the shingle installers more time, it does takes an experienced shingle installer, and the shingle materials used - such as the roof underlay and roof drip edge also cost real money.

But a great shingle installer, supplied with the right accessory shingle roofing materials, can install a 30 year shingle system that will last longer than a 50 year or lifetime system that was installed just average or poorly. So who really gets the best value for their money? 

Our Philosophy and Guarantee

Because General Roofing Systems has a Lifetime Workmanship Guarantee on all new shingle roof installations, we cannot compromise our shingle installations with inferior roofing material, sub standard shingle application methods, or roofing installers with-out an eye for detail. We are tied to our shingle roof installation workmanship – we can’t get it wrong.

When you get a new shingle roof from General Roofing, we only accept one way – great shingles, the best shingle installers, and shingle installation and application specs that go far above average or "acceptable" standards.

Many prospective customers ask us to lower our shingle installation specifications due to the marginal cost increase, but we can't as we guarantee or workmanship for the lifetime you own your home. Lowering our application specifications for shingle installation would cause us to change our workmanship guarantee and we are only interested in putting on the best roof you can own, the best way we know how.

General Roofing Systems Standards of Shingle Installation and Conduct

The installation specification that GRS shingle roofers install to is the highest standard – it is very important to us and we protect the integrity of our shingle installations with extreme diligence.

Our specification of shingle installation meets or well exceeds any Building Code, Association Specification, Manufacturer Specification, and Competitor Specification.

In addition to the shingle installation specifications, the way our shingled roofing is actually installed is also very important. Our method of shingle installation is described in detail at the following link:

Or, below is a an easy to use chart that shows the difference between standard shingle installations and the GRS Shingle Installation Standards.




The Average Roofing Company or Roofer

Free Estimates


Mostly standard

Free Roof Report and Attic Assessment

Standard with GRS. Roof Reports and Attic Assessments are critical to ensure that your new shingle roof will last the duration it should. Many re roofing jobs are done with-out correcting the inherent problems in the attic first which can cause your new shingles to only last half as long as they should.

New for 2011 - Roof Rot Sheathing replacement is included in GRS shingle pricing for up to 100 sq ft also.

Often not standard.

Roof reports take time and cost roofers money. GRS provides a full roof report by an experienced roofer (not an estimator or a salesperson). The roof report outlines roof status, type, concerns, possible remediation, photo’s etc.

The Roof Attic inspection is mandatory with GRS prior to the shingle installers starting work.

Quotation in Writing


Mostly standard.

Workmanship Guarantee

Yes – We maintain a lifetime shingle installation workmanship guarantee. Our shingle installers know they are working under the best shingle guarantee the shingle re-roofing business has to offer.

Often not standard. Many do not have workmanship guarantees and most won’t put it in writing. We put our lifetime workmanship in writing and is on all of our quotations, on our website, and on all of our company materials. There is no mistaking our claim to stand behind our work.

Manufacturer Warranty

Yes – We always meet or exceed the shingle manufacturer specifications. The GRS Standards of Shingle Installation far exceed the Shingle manufacturers.

Some shingle roof installers do not apply to the manufacturer spec and the warranty is then potentially compromised.

Building Code Requirements

Yes – We always meet or exceed the building code requirements. Here again we far exceed the requirements wherever we install shingle roofing.

Some shingle installers do not apply per the building code especially when the profit margins are low. Check your local building code.

Liability Insurance

Yes – We carry a 5,000,000.00 commercial liability insurance policy. This is very important for protecting our clients should something occur while our shingle installers are on site.

Many shingle roofers do not carry insurance, and if they do, many are not insured properly. It is expensive to carry a large commercial liability policy, but it protects our clients and workers.

Workers Compensation

Yes – We are registered and in good standing at all times with WCB. Here again, this is crucial for client liability.

Many shingle roofers do not carry WCB, and in some cases they carry it, but not for their workers.

Licensed & Incorporated & BBB Registered

Yes – We are a licensed and provincially incorporated,provincially registered company and are members of the BBB.

A business license is mandatory, Better Business Bureau is optional, and Provincial Registration of some sort shows good business practice.

First Aid Certification

Yes – All of our shingle installation staff (unless new) are certified in first aid as part of their standard training protocols.

First aid is a provincially legislated requirement and unfortunately many roofing crews when asked are not certified.

Fall Protection Training

Yes – All of our shingle installation staff are trained and unless new are certified in fall protection.

Fall protection training should be the first thing a roofer does in terms of training, and sadly, a great many are not trained formally.

Service after Installation

We maintain a 24 hour, 7 day per week, 365 day per year roof repair / service program.

Service after installation is one of the most challenging things we hear from client inquiries. So often the shingle installer has left the scene and not to be found to service their sub standard shingle installation work.

Roofing Certification

Yes – All of our staff (unless new) are formally trained in all areas of roofing certification.

Roofing certifications are so important. They ensure the roofers that are installing your roof shingles have fundamental principles of roofing and waterproofing in place. Here again, sadly most are not certified.

Safety Procedures

Every site has a tool box meeting, a fall plan developed and executed, and hazard assessments executed by each shingle crew every day.

Safety procedures are followed most of the time by most of the shingle roofers in some provinces and then in some provinces that we do installations in we find that very few roofers are heeding the realities of the danger our profession has.

Starter Course Shingles and High Profile Shingle Cap 

3 Tab (it's our preference for shingle starting).

GRS installs High Profile Architectural Shingle Cap standard as of 2011.

Many are using the new break a-part starters as they are less expensive. We don’t use them as the break tends to be not straight and at the gable it is important to have a very straight edge. Additionally, the coverage area of the break-apart starter is less than 50% that of a 3 tab shingle.

Storm Nailing

Storm nailing is a GRS Standard (minimum 5 - 6 nails per shingle)

Not Standard

Nailing pattern when installing shingles, removing nails from deck when removing old shingles. 

The GRS standard is the nail pattern to be minimum 5 - 6 nails, with each end being within 1 inch of the end of the shingle and at least 4 - 5 nails must be in the double laminate strip of the shingle, nails must be flush and straight.

We also mandate the removal of all old nails from the roof sheathing when re roofing prior to installation of new shingles.

Not Standard. The nailing pattern when installing shingles is so very critical as wind lifts the edges of the shingles and if the nails are not right close to the edge for the shingle that gives the wind opportunity to get lift on the shingle. Also, the laminate strip nailing is critical because a nail outside of the nailing line that has not hit the laminate does nothing – absolutely nothing to keep the shingle on the deck when the wind comes up.

Drip Edge Flashing


Often not standard

Rake Edge or Gable Flashing

Standard if appropriate to roof.

Very rare standard. Many roofers don’t want the added expense and time, our thinking is that it finished off the look of a high end application very well.

Color Flashing

Standard (Vents, valley metal, drip edge, rake edge, goose necks, skylights, and EVEN at wall with shake to shingle re roofing as profile of shake roof will likely be much higher than new shingles and the old galvanized metal flashing now shows poorly).

Often not standard. For many roofing companies, colored flashing are an upgrade.

Very few shingle re roofing companies we have ever seen will place colored flashing in the gap that shake re roofing leaves at the wall area from the height difference between the shingles and the shakes.

Replacing all vents, rubbers, etc.


Often not standard. We see it as a great way to finish off an installation. Our roofers will even spray paint your chimney stack etc to match if you wish,but whenever possible will install colored flashing for low maintenance.

Valley Flashing Metal


Often not standard. Again it is an issue of cost and time to install, however, metal in a valley is crucial as shingles break down over time and a leak in a valley is a catastrophe.

Ice and Water at Eaves



Often not standard. It should be standard as many building codes call for it, and in areas like Calgary with the freeze-thaw syndrome it should be standard as the ice backs up in gutters and then under shingles at the eave.

44” Ice and Water at Eaves

Standard Commercial Grade

Rare standard.

Ice and Water in Valleys


Often not standard. Often this is not standard, the problem is that when the shingles or the valley metal fail (if valley metal was installed) there is nothing there to stop the water from going in to the roofing system. A leak in a valley is the worst place to have a roof leak.

44” Ice and Water in Valleys


Rare standard.

Ice and Water to Valley after Valley Metal is Installed



Almost never done. GRS installs ice and water to the valley first, then the valley metal, and then re install another layer of ice and water on the edges of the metal valley. It becomes a monolithic roof installation and there is no way it can fail.

Synthetic Premium Underlay to Entire Roof

Standard, we never use tar paper.

Often not standard. Many companies unfortunately see this as a cost they’d rather not incur and install the shingles right to the bare sheathing on the roof deck or they use an inexpensive brittle tar paper.

Wrapping complete roof 100% in underlay



Rare standard. Most shingle installers see it as overkill to concern themselves with bringing underlay right up to a ridge for a part roll situation or wrapping it around the hips etc, they prefer to cut it at the hips – we don’t, we wrap it and then cut to ensure the complete roof deck is wrapped in underlay.

Underlay to roof even if steep.


Rare standard. Most companies go with the manufacturer spec on this issue. GRS does not. The issue is simple, when a high wind takes your shingles is not it better to have the protection of a roof underlay even if it is steep and would likely run most water often, but it is not a guarantee.

Ice and water “neck tie” to every vent, stack, etc


Standard and radically enforced

Rare standard. It causes our roofers to slow down and really think about the opening… every single opening is looked at from a waterproofing perspective and most roofing companies won’t require their roofers to do this. It solves 90% of our after service issues.

Lowering each field shingle 1/16”

Standard and radically enforced

Very unusual standard as it costs much more as we use much more material, but it keeps blow offs from occurring.

Caulking under the flange of vents, goose-necks, etc



Unusual. Many roofers miss this and it is an important component to thinking in terms of waterproofing instead of water shedding. GRS caulks the underside of every vent, goose-neck, etc.

After installation inspection


Not always standard. Some roofing companies will inspect installers work to varying degrees, and some of those will inspect the first few roofs a crew does for them and then slack. GRS inspects each and every roof, it does not matter how long an installer has been with us. Not only do we inspect, but we photo the inspection for each specification we hold as very important and the report is available to you the client anytime you wish.










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Re Roofing and Shingle Installations by GRS in the following communities;

Calgary, Red Deer, Edmonton, AB, Fort McMurray, Lloydminster, Saskatoon, Regina, SK, Medicine Hat, Lethbridge, Canmore, AB, Cranbrook, Kelowna, Vancouver, Whistler, BC, Winnipeg, MB, Toronto, ON and points between. British Columbia, Alberta, Saskatchewan, Manitoba, Ontario.

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