When to replace a roof

The decision of whether to repair or replace a roof is a major one. Not only is a new roof a significant expense, “keeping a roof over your head” is something that will keep you and your family safe, warm and dry. You want to make well-informed decisions and know that you won’t be overspending on something you don’t need.

There are a few factors we consider when determining whether your roof needs replacing or repairing.

  • How old is your roof?

First, we look at the age of the roof. Most roofs are designed and built to last around 20 to 25 years, depending on the materials used, the installation method, the climate, and how well you look after your roof. That’s right … you need to look after your roof. Read more on that below.

There will come a time when wear and tear over the years make it uneconomical to continue to spend on repairs. At Sumich Plumbing & Drainage we’ll always try to repair something before replacing it whenever possible. But we also know that, like cars or appliances, there comes a point when continuous repairs are more costly than replacement.

In short, if your roof is only five to 10 years old, then you should be able to get away with repairing instead of replacing your roof. If it’s 20 or more years old, you’re possibly looking at a roof replacement project. Anything in between is where it’s not as clear cut. If your roof is around 15 years old, it’s best to get a professional to assess it. Get in touch with our team today for roofing services.

  • Is there visible external damage?

If you can see noticeable damage to your roof – missing tiles or shingles, chipping paint, rusty areas, loose panels, moss or mould – then it’s time to do something about it. You wouldn’t want any loose tiles or panels coming off and hurting someone or causing damage to the property below. And you don’t want existing wear and tear to get worse and beyond repair.

The decision to repair vs replace part or all of your roof depends on how much damage or wear and tear there is. There is no magic formula or percentage, but if a larger portion of the roof tiles is damaged, or there is a large section of sheet metal that needs work, then we look at the likelihood of the same damage affecting the rest of the roof. You might be better off replacing the entire roof.

  • Is there visible internal damage?

If there is water damage on your ceiling that you can see from inside the house, that is a clear sign that either water is coming in from the outside or that there are issues with the internal plumbing from an upper level of the house. The Sumich team can assess which of these it is.

Visible internal damage includes water stains, leaks, wet timber in the walls, mould on the ceiling or walls. There is a high chance that these signs of internal damage are clues that there is actually external damage to the roof or the drainage around it (such as gutters, spouting, flashings, etc).

Again, there is no mathematical equation or ratio that tells us whether it’s time to replace a roof. But the professionals at Sumich Plumbing & Drainage have over 30 years of experience in Auckland and will look at a combination of factors.

The age of the roof, plus the amount of damage inside and out, plus the likelihood for more damage or wear or tear all factor into the decision-making process when it comes to deciding whether to repair or replace your roof.

  • Have you been looking after your roof regularly?

Unfortunately, it isn’t a case of “out of sight, out of mind”. If you ignore regular cleaning and maintenance, you’ll likely end up with unwanted repair bills.

Roof maintenance consists of checking for loose tiles and repairing or replacing them as needed. It might include cleaning, particularly if your roof gets hit with a lot of bird poop. If your roof is old, there may be sections that need rustproofing or paintwork. The gutters and spouting need to be monitored and cleaned regularly. And the flashings and joints need to be checked and repaired as needed.

Roof repairs, roof maintenance and roof replacements are specialist areas for the Sumich Plumbing & Drainage team. We have been maintaining, repairing and installing roofs all over Auckland for over 30 years. You can rest assured you’re talking to experienced professionals when you give us a call

Get in touch for a no-obligation quote.


There are a number of plumbing and drainage companies in Auckland, so why choose Sumich?

Founded by owner-operator Chris Sumich in 1991, Sumich Plumbing & Drainage has one of the most experienced teams operating in Auckland. Our team has a combined experience of over 100 years and we’ve seen a comprehensive range of scenarios and solutions over the years. Clients trust us to give honest, transparent advice and service.

As registered members of the New Zealand Plumbers, Drainlayers & Gasfitters Association, we are professional, licensed Auckland plumbers for all of your plumbing, drain laying, gas-fitting and heating needs. Give us a call to see how we can help.