Roof Repair or Replacement: How to Decide
Most roofs that get replaced could have been repaired a few years earlier. Most roofs that get repaired forever should have been replaced. Here is how to tell which one you have.
Every roofer in Kane County will give you an answer to this question, and a fair number of them will give you the answer that suits them. We would rather hand you the reasoning so you can check it yourself.
There are four things that decide it. Age, how many layers are already up there, what the decking is doing, and whether the failures are in one place or everywhere.
1. How old is the roof, honestly?
Asphalt shingles in northern Illinois give a realistic 20 to 30 years, and the range is wide because orientation matters more than most people expect. The south and west elevations weather noticeably faster than the north side of the same roof — it is common to find one slope with years left and another that is finished.
If you do not know the age, there are ways to find out. A permit search at your village will usually turn up the last reroof. Sellers' disclosures from your purchase sometimes list it. And a tear-off edge at a rake or a valley will show how many layers are up there, which narrows it down.
Under 15 years: almost always a repair, unless there is storm damage or an installation defect. 15 to 20: usually a repair, but worth planning for. Over 20: the calculation changes — see below.
2. How many layers are already on it?
Illinois practice, and most local village codes, allow a maximum of two roof coverings. Hampshire states it explicitly: “not more than two applications of any type of roof covering shall be allowed.” Campton Hills and West Dundee say the same.
So if you already have two layers, a third is not an option. The roof has to come off. That is not bad news — a tear-off is the better job anyway, because it lets us see the decking, install proper ice-and-water shield at the eaves and valleys, and fix the ventilation at the same time.
If you have one layer and the shingles are still sound, a repair keeps its full value.
3. What is the decking doing?
This is the one nobody can answer from the driveway, and it is the one that most often changes the number.
Soft spots underfoot, sagging between rafters, daylight visible from the attic, or dark staining on the underside of the sheathing all point to moisture that has been getting in for a while. Decking that has gone soft cannot hold a nail, and shingles fastened into it will lift in the first serious wind.
Ask any contractor bidding your roof for a per-sheet unit price on decking replacement, in writing, before work starts. That way if the roof opens up and there is rot, the cost is something you already agreed rather than a number invented on the day. We quote it that way as standard.
4. Is the failure in one place, or everywhere?
Localized failures are repairs. A leak at a chimney, a cracked pipe boot, a section of lifted shingles at a rake edge, ice dam damage at one eave, a valley that was never flashed properly. These are specific, findable and fixable, and the rest of the roof is doing its job.
Distributed failures are replacements. Granules in the gutters everywhere rather than in one downspout. Shingles curling or cupping across whole slopes. Bald patches on multiple elevations. Brittle shingles that crack when lifted. Those say the mat itself has reached the end, and patching one area just moves the next leak somewhere else.
A useful test: if you have paid for three repairs in five years, you are on a replacement schedule already, just an expensive one.
What repairs and replacements actually cost around here
Published Chicago-area figures for August 2026 put the average roof repair at $1,030, with most homeowners paying between $346 and $1,728 (Angi). Illinois contractor tiers run roughly $150–$500 for a minor leak repair, $300–$1,500 for moderate work like shingle sections and flashing, and $1,000–$3,000 or more where there is structural damage. Hail damage repair specifically runs $700–$4,000.
Replacement is a different order of magnitude — roughly $400–$600 per square (100 sq ft) installed for architectural shingles in this market. We publish the full breakdown, with every source named and dated, plus a calculator, on our roof replacement cost page.
The arithmetic that matters is not repair versus replacement today. It is repair cost divided by years of life it buys, against replacement cost divided by 25. A $900 repair that buys eight years is good value. A $900 repair that buys eighteen months is not.
One more factor: whether a storm is involved
If your roof was under a documented storm, the calculation changes again, because part of the cost may be an insurance matter rather than an out-of-pocket one.
Kane County took two derechos and a tornado outbreak in 2026 alone. We keep a dated record of every event with National Weather Service sources, town by town, so you can check whether your address was under one.
Wind at 60 to 75 mph breaks shingle seal strips without necessarily removing shingles. The roof looks intact from the ground and fails in the next storm. That is exactly the kind of damage that is worth documenting while the claim window is open.