4 Critical Factors to Consider when Deciding to Replace a Roof

Trying to figure out if you should replace your roof?


Roof replacement is a major expense and smart homeowners know they should maximize the useful life of their existing roof as much as possible. However, wait too long, and a couple days of hard winter rains or snow can cause more damage to your house than the cost of that complete roof replacement you were too cheap to spring for last summer.

Deciding when to do your new roof can be a complex and wrenching decision for many homeowners. This decision can be complicated even more when it comes time to sell your house; roof replacement is a common source of contention between home buyers and home sellers. Hopefully, this blog can help!

The answer to your re-roof question has a lot to do with evaluating 4 critical factors.

  1. What is wrong with the roof
  2. What is your personal ability to maintain the roof
  3. What is your desire for reliability
  4. What are the plans for the house

Note: For the purposes of this blog, we will be discussing composition roofing shingles, which are the most commonly installed roofs. These same concepts apply to other types of roofing, but perhaps less so. Some types of roofing, such as slate or clay tile roofs, have longer service lives and much more expensive replacement costs, which can change the equation slightly.

The sequence below is written a little like an identification key. Start at 1 and work your way to 4 and hopefully this blog will help answer your roof replacement question for you.

1. What is wrong with the roof? Chronic problems VS age

When plumbing vent flashings look like this the rest of the roof is likely to require replacement soon

When plumbing vent flashings look like this, the rest of the roof is likely to require replacement soon. However, this is an easy repair if there is nothing else wrong. A handy homeowner could repair a damaged flashing like this.

Roofs tend to fail for 3 reasons

  • They leak at penetrations or junctures
  • They fail because they are not correctly installed – chronic problem.
  • They get old and unreliable – age

If a roof is leaking at penetrations, such as the flashing shown above, this is usually cost-effective to repair. The roof may not require replacement yet.

If a roof is leaking due to poor installation, put your money on needing to replace the roof. Diagnosing the failure is often too difficult for a poorly installed roof. One of the most common unreliable installations is the “overlay” roof, where one layer of roofing is installed on top of an older layer. This is a complex subject that could be the discussion of a whole other blog.


This brand new roof was poorly installed and vulnerable to premature failure that could be impossible to repair without roof replacement.

This brand new roof was not fastened correctly, making it vulnerable to premature failure that could be impossible to repair without roof replacement.

If the roof is just getting old and you are worried about its reliability – go on to question 2.

2. What is your personal ability to maintain the roof? 

If you are relying on hiring roofers to repair your old roof, you want to compare the repair cost against replacement cost. Do a cost-benefit analysis. For example, if you have an $8,000 replacement cost and a $2000 repair cost, and the roof is old and close to the end of its life, you probably want to replace the roof and forego the repair.

Obviously, this math changes if you can do your own repairs on this roof for $50 in materials. If you feel comfortable repairing the roof yourself, you will not be at the mercy of waiting for a roofing company to come out after that heavy snow in January. You will be able and willing to fix it yourself, at least temporarily, thus reducing your risk and improving your ability to maximize the useful life of the existing roof.

3. What is your desire for reliability

This is something you need to decide for yourself. If you are away from home a lot, have no ability to repair your own roof and the thought of a roof leak keeps you awake at night….. I’d spring for the new roof sooner rather than later. It’s water. Roofs leak. Don’t let the stress take the joy out of your life.

Also, you need to consider the stress of roof replacement as an emergency rather than scheduled maintenance. Fighting roof replacement in the rain or snow can be unpleasant at best. Ever heard the expression: they have you over a barrel? Emergency roof replacement leaves little opportunity to compare and contrast roofing estimates and can result in a more expensive and less reliable roof.

4. What are your plans for the house? 

If you have beautiful finishes like this georgous wood ceiling, you have less tollerance for a roof leak.

If you have beautiful finishes like this gorgeous wood ceiling, you have less tolerance for a roof leak.

If you are planning on doing a 2nd-floor renovation in two years or adding a dormer, the reality is, you do everything in your power to make the old roof last two more years. Blue tarps are not out of the question. You don’t want to put on a new roof and then tear it off a few years later.

On the other hand, if you have no plans for renovation, and you have stunning finishes inside that would be damaged by a roof leak, these finishes start dictating the level of risk you can take. I inspected a house the other day with the most beautiful clear cedar ceiling that was all water stained from roof leaks. Too bad, they waited just one year too long and permanently damaged this ceiling.


When, exactly, a roof needs to be replaced can be a source of tension between home buyers and home sellers when in the midst of a real estate transaction. It is complicated by the fact that there is often not a single metric, but a host of competing factors to consider beyond simply the condition of the roof.

This is a great example of how subjective home inspection can be: you can often get more than one opinion on the exact same condition and the same condition can be viewed differently by buyers and sellers.

Home inspectors are constantly muddling into these subjective gray areas and I think we are at our best when we avoid black and white and focus on the larger picture of helping clients understand what they are buying in the larger, more general sense:

  • “Your roof is old and will need to be replaced soon.”
  • “Your roof is new, but not installed in a reliable way and may not perform as intended.”

I hope this short blog helps start a conversation about the complexity of the subject and helps you make a good decision about when to re-roof your house.

Dylan Chalk

Author: Dylan Chalk

Dylan Chalk is the author of The Confident House Hunter – a book to teach home buyers how to look at and understand houses: Cedar Fort Press www.dylanchalk.com. In June of 2017, Dylan's book The Confident House Hunter won the Silver Award from the National Association of Real Estate Editors. He is also the founder of ScribeWare inspection report software offering innovative and simple report-writing solutions - www.getscribeware.com and he is the owner of Seattle-based Orca Inspection Services LLC. In early 2017 Dylan became the Vice-President of Western Washington chapter of (ASHI) American Society of Home Inspectors. www.orcainspect.com.