Roof repair vs replacement

The choice between repairing and replacing a roof turns on three things: the age of the roof, the extent of the damage, and whether the damage is from a covered peril. A roofer who only installs roofs will recommend a replacement, and a handyman who only patches will recommend a patch. The decision needs a diagnosis, not a sales call.

The decision rule

If the roof is young, the leak is localised and the decking is sound, a repair is almost always the cheaper answer. If the roof is near the end of its service life, the damage is widespread, or the shingles are failing across the field, a repair is money spent on a roof that will still need replacing.

Ask the roofer to state in writing how many years a repair would buy and what would trigger a replacement. A specific answer is useful; a vague one is a sales pitch.

What a repair involves

A repair can mean replacing a few shingles, resealing a flashing detail, patching a valley or repairing the underlayment around a penetration such as a vent or a chimney. The cost is dominated by access and by how much of the surrounding material must be disturbed, which is why two quotes for the same leak can differ.

Ask whether the repair will match the existing shingle in colour and profile, and whether the roofer will warrant the repair separately from the rest of the roof. A repair that voids the manufacturer's warranty on the field is a hidden cost.

What a replacement involves

A replacement includes tear-off, disposal, underlayment, flashing, ventilation and the new covering, and each is a separate line in a proper quote. The number of existing layers and the condition of the decking are the two variables that most often change the price after the work starts.

Ask for the decking replacement price per sheet in the contract, because rotten decking is the most common surprise on a re-roof and the most commonly marked up. A quote that does not state it is an incomplete scope rather than a lower price.

Source: Freddie Mac Primary Mortgage Market Survey, as published at freddiemac.com/pmms. National averages for conforming loans; your rate depends on credit, points, loan size and property.

The published context

There is no official price for roofing, but the cost of the work is driven by materials and energy, and Statistics Canada publishes a consumer price index that shows how those categories have moved. If you own the home with equity, Freddie Mac publishes the national average mortgage rates that home equity products are priced against, and the table below is that survey.

Insurance and the order of operations

If the damage came from a storm, hail or a fallen tree, the insurer's adjuster sets the scope and the roofer prices against it. File the claim before signing a contract, because signing first hands the scope to the contractor and can reduce what the insurer pays.

If the roof is simply worn out, no policy covers it and the whole cost is yours. That is the case in which the repair-or-replace decision is purely financial, and the financing comparison decides whether the job costs a few hundred dollars of interest or a few thousand.

Financing either option

The example below uses the Federal Reserve H.15 bank prime loan rate and a standard amortising schedule. It is arithmetic from a published rate, not a quote, and it lets you compare a contractor plan with an independent benchmark.

Worked example, with the assumption stated: $12,000 borrowed at the Federal Reserve H.15 bank prime loan rate of 6.75% (published 2026-09-16) repaid over 60 months on a standard amortising schedule. That gives a monthly payment of $236.20, total interest of $2,172.09 and a total repayment of $14,172.09. This is arithmetic from a published rate, not a quote: a real APR includes fees and is set by the lender from your credit, so your figures will differ. A home equity product is often cheaper per dollar because it is secured, but it puts the home at risk on default. Compare both over the same term.

Ask each contractor for the cash price and the financed price in writing. If a contractor will not give a cash price, that is information about how the financed price was built.

Ask how the roofer will protect the property during the work. Tear-off sends debris into gutters, gardens and driveways, and the cost of a damaged window or a blocked drain is not in the quote. Confirm that cleanup and nail sweeping are included.

Ask about ventilation while the roof is open. Inadequate attic ventilation shortens the life of the new covering and is the most commonly skipped item on a re-roof. If the quote does not mention it, ask whether the existing ventilation meets the manufacturer's warranty conditions.

Get the permit question answered. A re-roof usually requires a permit in jurisdictions that enforce building codes, and a contractor who proposes to skip it is shifting the risk to you. Confirm who pulls the permit and whether the fee is in the quote.

Ask for the manufacturer's warranty terms on the shingles and the workmanship warranty from the contractor separately. The two cover different failures, and a workmanship warranty that lasts only a year is common, so read the terms before comparing quotes.

Ask the roofer to put the warranty terms in the contract rather than describing them verbally at the kitchen table.

Where these figures come from

Related pages

• Roofing costs by state and province
• Financing a roof replacement
• Metal roof vs shingles
• Loan payment calculator

Frequently asked questions