Almost every roofing call in Calgary starts the same way. Something happened, a stain on the ceiling, shingles in the back yard after a chinook, or a neighbour who just got a whole new roof paid by insurance, and the homeowner wants to know one thing: do I patch this, or do I replace the whole thing?
The honest answer is that a repair is the right call more often than most roofing companies admit. It is also the wrong call more often than most homeowners want to hear. The difference comes down to five questions, and you can answer four of them yourself from the ground.
The five questions that decide it
1. How old is the roof? Age is the single strongest signal. A builder grade asphalt roof in Calgary typically gives you 12 to 18 years before the shingles start losing their protective granules in earnest. Under 10 years, repair is almost always correct. Past 18, you are paying a roofer to fix one part of a system that is failing everywhere at once.
2. Is the damage in one place, or everywhere? A tree limb that tore open one slope is a repair. A roof that has shed granules on every southern and western face is not. Look in your eavestroughs and at the bottom of your downspouts. Granules that look like coarse black sand mean the shingles are losing the layer that shields them from ultraviolet light, and that happens across a whole roof, not in one patch.
3. Has it leaked more than once, in more than one spot? One leak is an event. Two leaks in different rooms is a pattern, and it usually means the underlayment and flashing are at the end of their service life. Chasing pattern leaks one at a time is the most expensive way to replace a roof.
4. Are the shingles brittle or curling? Healthy shingles flex. Old ones snap. If corners are curling up, lifting at the edges, or cracking when they are gently bent on a mild day, the asphalt has dried out, and no amount of sealing brings it back.
5. Is the decking still solid? This is the one you cannot check yourself, and it is the one that changes everything. If water has been sitting on the plywood underneath, the sheathing may be soft or delaminating. Nailing new shingles into soft decking guarantees you will be back on the roof in a few years.
The 30% test
When the first four answers are mixed, use the money to break the tie.
Get a written repair quote and a written replacement quote for the same roof. If the repair costs more than roughly 30% of the replacement, and the roof is past the halfway point of its expected life, replacement is usually the better purchase. You are not just buying shingles at that point. You are buying fresh underlayment, new flashing, a new warranty, and a clock that starts over.
| Situation | Usual Answer | Why |
|---|---|---|
| Roof under 10 years, one damaged area | Repair | The rest of the system still has most of its life left. |
| Roof 10 to 15 years, wind damage on one slope | Usually repair | Worth doing if matching shingles are still available. |
| Hail bruising across several slopes | Replace, often through insurance | Bruised mats fail early even where they look intact. |
| Repeat leaks in different rooms | Replace | The underlayment and flashings are done, not just the shingles. |
| Roof past 18 years, heavy granule loss | Replace | Repairs cannot restore shingles that have lost their surface. |
| Soft or rotted decking found | Replace that section at minimum | Fasteners do not hold in compromised plywood. |
Where Calgary changes the math
Most roofing advice online is written for milder climates. Three local forces push Calgary roofs toward earlier replacement than the warranty on the package suggests.
Hail. Southern Alberta sits in one of the most hail prone corridors in the country. Hail does not always punch holes. More often it bruises the shingle, crushing the mat under the surface so the granules let go months later. That is why a roof can look survivable from the driveway and still be finished. We cover the warning signs in our guide to hidden hail damage.
Chinooks. A 20 degree temperature swing in a single day makes shingles expand and contract, works fasteners loose, and repeatedly melts and refreezes snow at the eaves. That freeze and thaw cycle is what drives ice dams and the leaks that come with them.
Wind. Sustained chinook winds find every shingle that was not sealed properly. If you lose shingles in the same spot after every strong wind, the problem is the nailing pattern or the starter course, not bad luck.
Repairs that are genuinely worth doing
Do not let anyone talk you into a replacement when you have one of these:
- Flashing failures. Around chimneys, skylights and wall junctions, the metal fails long before the field of the roof does. Replacing flashing and re-sealing is standard repair work.
- A small number of blown shingles on a roof that is otherwise in good shape and young enough that matching material is still made.
- Exposed or backed out nails popping through shingles. Common, cheap to fix, and a real leak source if ignored.
- A single failed pipe boot. The rubber collar around a plumbing vent cracks with ultraviolet exposure, and it is one of the most common leak sources we see. It is a small job.
- Eavestrough and downspout problems being mistaken for roof leaks. Water backing up over the edge soaks fascia and looks exactly like a roof failure. Our guide to soffit and fascia explains how that system works.
When patching is the expensive choice
Delay has a price, and on a roof it compounds. Water that gets past the shingles does not stop at the plywood. It soaks insulation, which loses its R value permanently, then reaches drywall, framing, and eventually the finishes you actually care about. What starts as a shingle problem becomes a decking, insulation and interior problem, and the bill grows at every step. We walk through that cost curve in the real cost of delaying a roof repair.
There is also a sales angle worth knowing. If your roof is a year or two from replacement anyway, a repair now buys very little time while spending money that does not come off the replacement price later.
What a proper inspection should tell you
A useful roof inspection is not a walk around the yard. Before you accept either recommendation, you should be handed:
- Photographs of the actual damage, taken on your roof, not stock images.
- A stated shingle type and approximate age, since that anchors every other judgement.
- A note on decking condition wherever it could be observed.
- The condition of flashing, vents and pipe boots, which are separate from the shingles.
- A written quote for the repair and, where relevant, for replacement, so you can run the 30% test yourself.
If a contractor will not put the recommendation in writing with photos, that tells you something useful about the recommendation. Our guide on choosing a roofing contractor in Calgary covers the rest of the vetting.
Frequently asked questions
Can I just replace one slope of my roof? Sometimes, yes. Slope by slope replacement is legitimate when damage is confined to one face, for example a single hail hit on the west side. The trade off is a visible colour difference, because new shingles never match weathered ones exactly.
Will a repair void my manufacturer warranty? A competent repair does not. Improper work can. Manufacturer coverage assumes the system was installed and maintained to their specification, which is why the repair should be documented. See how roof material warranties actually work.
My neighbour got a new roof from insurance. Should I file too? Only after someone confirms you actually have storm damage. A claim for ordinary wear and tear gets denied, because Alberta policies cover sudden damage rather than age. If you did take hail, the process is in our Alberta roof insurance claim guide.
How long does a replacement take? Most Calgary homes are a one to two day job for the roof itself. See how long a roof replacement takes for what happens on each day.
Not sure which one you need?
If you are weighing a repair against a replacement, the cheapest next step is to have someone look properly and show you photographs of what they found. We serve Calgary and the surrounding towns, and we will tell you when a repair is enough, because a roof replaced two years early is money you did not need to spend.
Call (587) 969-2720 or request a free assessment.