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Signs That Your Roof Needs to Be Repaired or Replaced (And How to Choose a New One)

6 minute read

By Lesley Harrison

The roof is one of the most important parts of any property. Not only does it protect the interior from the elements, but it also protects the structure of the building. Depending on the materials a roof is made from, it could be expected to last for decades with proper care and maintenance. It’s important to inspect your roof regularly for signs of damage and decay and act quickly when issues arise.

How Long Should a Roof Last?

The average lifespan of a roof depends on the material the roof is made from and its style. Asphalt shingles can be expected to last between 15 and 40 years depending on their quality. Wooden roofing typically lasts about 30 years, as long as it is properly maintained. The most durable roofs are metal ones, being able to survive extreme weather and last up to 50 years. Clay tile roofing is also durable and can be expected to last for at least 30 years. With proper maintenance, a clay tile roof could even last 100 years.

Common Signs of Roofing Issues and What They Mean

Regular maintenance is essential to keep a roof in good condition. Knowing the early warning signs of damage to your roof can help you identify what sort of repair work is required and make decisions about when a roof replacement might be a better option. Some issues, such as a buildup of debris in the gutter or a small amount of storm damage to tiles, can be fixed easily enough. Other issues are a sign of more serious underlying problems.

Pramote Polyamate / Getty

1. Mould or Moss Growth

Mould and moss growth on a roof isn’t necessarily a sign of damage. However, if the growth is left unchecked it could become a problem. Moss holds water, which means it can become quite heavy after a rainy period. In addition, the growth can get between tiles, causing them to separate and let water penetrate the roof. Moss grows back quickly, so once it’s started growing on a roof, it can be difficult to completely eradicate, but it’s important to keep it in check.

2. Missing or Damaged Tiles

It’s a good idea to inspect your roof at least once a year to look out for loose, damaged or missing tiles. Additional inspections should be performed after periods of extreme weather. Check the roof from the exterior and, if possible, by going up into the attic. Look for gaps where light can get through or tell-tale signs of leaks after it rains. If one or two tiles are missing, replace them. If there are several, this may be a sign that your roof is due for replacement.

3. Damaged Flashing

Flashing is installed around chimneys, roof vents and anything else that protrudes from the roof. Its job is to prevent water ingress. Over time, the caulking around the flashing can dry out, and the flashing itself may deteriorate and start to come away, letting water penetrate delicate areas. Loose flashing can lead to irreparable damage to your roof. If you notice signs of decay close to a chimney or vent, have it repaired as soon as possible.

4. Sagging

If a flat roof is visibly sagging, or your roof deck or rafters are starting to collapse inwards, this is a sign the roof is severely decayed. Often, sagging is caused by water penetrating the roof and the rafters being unable to handle the extra weight. If this is a localized issue, it may be possible to fix the leak and replace the damaged rafters. If the problem is more widespread, a full roof replacement may be required.

5. Falling Mortar

Mortars are usually found at roof junctions. They have a much shorter lifespan than the tiles and shingles themselves, so it’s important to check them regularly for signs of damage. Mortars can start to break down due to changing temperatures and may eventually separate from the roof and fall off. With very old roof designs, mortar was used as a bedding for tiles, so broken down mortars are a more serious problem that could indicate the roof itself is due for replacement. With more modern roofs, the mortars are easier to replace by themselves.

Understanding Your Roofing Options

Whether you’re looking for a residential roof or a roof for a warehouse or other commercial building, there are several materials and styles to choose from. Tiles and shingles have traditionally been popular for residential properties. Flat roofing is also an option, one that is becoming increasingly popular thanks to the ease of maintenance it offers. There may be restrictions on the types of roofing materials that can be used in certain areas. For example, in conservation areas in New South Wales,1 there are some requirements all property owners must abide by to preserve the look and feel of those areas.

Choosing Roofing Materials

Some common roofing materials include:

Modern properties may have roofing with solar panels built in, instead of being attached to the top of the existing roof. Each of these roofing options has a distinctive appearance, and the cost of these options can also vary significantly. Both factors, and ease of maintenance, should be considered when choosing the materials for a new roof. It may be appealing to keep a slate roof for a period property that was built with one, but if finding replacement slate from an architectural reclaimer is going to be difficult, then doing so could be an expensive option.

Tiles vs. Flat Roofing

Flat roofing is quick and easy to install and is popular in properties that are relatively small. However, this type of roof is prone to developing leaks. It’s also common for water to build up on the roof if there are any areas that aren’t perfectly flat, putting strain on the felt. A flat roof for an average-sized home typically costs around $4,000 to install.2

Sloped roofs with tiles are more long-lasting if they’re properly cared for. However, they can be costlier to install. The actual price depends on the material used, but as a rule of thumb, Australians can expect to spend between 2% and 4%3 of the value of their home on a new roof.

Beware of ‘Storm Chasers’

It’s common for property owners to inspect their roofs after a storm or some other event that causes damage. While this is a sensible move, it’s something scammers try to take advantage of. Dishonest companies call on property owners offering to fix storm damage. In some cases, these companies charge vastly inflated prices, taking advantage of the property owner’s desperation. Some scammers may simply take the victim’s money and vanish without performing any work at all.

What To Look for in a Roofing Company

When choosing a roofing company, check to make sure they’re licensed to operate in your area. Membership of trade associations such as the Metal Roofing Cladding Association of Australia4 is a good sign of a reputable company too. Most trade bodies have a public membership list that prospective customers can check to confirm a contractor’s claims. Look at reviews online, too, but always keep in mind that most directories and search engines don’t vet reviews to ensure they’re from verified customers. Word-of-mouth recommendations from friends and family should carry more weight.

Get Several Quotes Before Choosing a Roofing Company

As with any large job, it’s well worth getting several quotes from local contractors to get an idea of reasonable prices for your roofing job. Ask each contractor to itemize the quote so that it’s clear what is covered. If there’s a significant discrepancy between quotes, ask the contractors to justify their pricing. Take pricing into account when choosing the contractor, but also consider customer service, reputation, any warranty offered and the timeline in which they can do the job.

Lesley Harrison


Lesley Harrison is a technical writer and open source software enthusiast with a passion for all things "data". In her spare time she coaches youth sports and loves exploring the English countryside.