Home Inspection

Common Roof Problems Found During Home Inspections

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Hubert Miles

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The roof is one of the most important features of a house. Not only is it a key support structure, but it also acts as the building’s first line of defense from the outdoor elements such as rain, snow, wind, and extreme temperatures. 

Over the years, it’s very common for the roof to become damaged due to its exposure to these weather conditions, and eventually, it will need repairing or replacing. If you’re buying or selling a home, it’s important to seek the expertise of a home inspector so they can assess any issues with the roof before the sale is finalized.

Common roof problems found in home inspections include a failing structure (sagging), poor installation or workmanship, leaks, missing/damaged shingles, improperly installed flashings, and clogged gutters and downspouts.

It’s not easy to determine the condition of a roof purely by its look, especially for the untrained eye. If you’re about to spend a significant sum of money on a new home, a NACHI or ASHI certified home inspector will be able to help you identify problems the roof could be suffering from, saving you some money in the process.

According to HomeAdvisor.com, the average roof repair cost is between $353 and $1,439 with an average cost of $890, but this varies considerably depending on the severity of the issue. A full roof replacement can cost anywhere from $5,351 – $10,819 or more. That $500 investment for a home inspector doesn’t look too bad all of sudden, does it?

Want to read more about red flags in home inspections? We have a list of red flags during a home inspection that can help you select a new home with confidence.

In this article, we will take a look at 13 home inspection issues to do with the roof. Let’s get into it.

The Roof Structure 

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The home inspector will assess the structural integrity of the roof during their visit. They will check for specific structural problems such as roof sagging, roof spreading, as well as rot and rust to key support points.

Sagging occurs in areas across the roof due to weakened joists that hold the roof in place. Similarly, roof spreading occurs when the downward pressure of the weight of the entire roof becomes too much and starts to move the structure out of place. Typically, these issues are many years in the making. The longer they are left untreated, the more severe the damage.

Problems such as roof sagging and spreading usually arise due to exposure to large amounts of rain and snow, especially if the drainage system is inadequate. It can also be an indication of more serious issues, such as the foundation shifting, sinking, or settling. This would require both a roof and foundation repair.

Home inspectors will assess the roof a couple of ways. Provided it’s safe and weather permitting, the home inspector will walk the roof to get a sense of the strength of the roof sheathing. Walking on the roof helps the inspector feel how much flex is in the roof sheathing particularly in key areas such as valleys, around chimneys, chimney saddles, and around roof penetrations.

The other way is through the attic space. This is an area that often tells the story the best. The attic allows you to see prior or current leak activity. You can also see whether the roof structure is built from traditional joist and rafter construction or roof trusses.

Defects in the roof structure can tell an inspector a lot about the overall strength and health of the house. Inspectors will be looking for damaged or altered trusses, proper bracing on rafters, twisting of rafters, and the condition of the roof sheathing.

The Interior 

When we think about roof inspections, we tend to think about the condition of the roof exterior while forgetting about the interior. This is a vital part of the home that can give us great clues to potential issues that could be affecting the rest of the building. 

The interior inspection includes checking the attic for proper insulation to ensure that there is no unnecessary heat loss during the winter months. Inspectors will also assess the level of ventilation in the attic, ensuring there is no build-up on mold or mildew, which are indicative of some form of water penetration.

A lack of ventilation in the roof can lead to increased condensation which had the potential to deteriorate the roof prematurely due to timber rot.

The inspector will be on the lookout for signs of leaking in the form of water stains, delaminating wood, and damp smells, all of which can cause roof decay and extensive damage.

The home inspector is also looking for water spots on the ceilings that could clue them into potential problem areas to focus on inside the attic.

Unfortunately, sometimes not all areas of the attic are accessible for inspection. This is common in vaulted roofs and flat roofs. This will often prompt the inspector to direct you to have an examination by a licensed roof contractor which could involve removal of a portion of the drywall to access the underside of the roof.

Roof Materials

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Roofs are made from a number of overlapping materials that are designed to keep the building safe from water damage while keeping it well insulated and ventilated. According to NACHI, some of the most common materials used are asphalt, metal, wood, concrete and tile, and single-ply.

Each of these materials has advantages and disadvantages and will be susceptible to different types of damage. On top of this, not all materials offer the same level of structural strength as others, while some materials may pose a potential fire hazard. For example, asphalt shingles and wood shakes are far less fire-resistant than concrete and metal. 

The inspector will identify the roofing material used, assess whether or not it is appropriate for the location and climate it must endure, and check to see visible signs of wear that are common for the material.

Roofing materials do have a limited lifespan. The following chart includes the estimated material lifespan. While this is a commonly accepted life expectancy, a replacement could be required much earlier. Typically, if a roofer has to replace 30% or more of the roof, a full roof replacement would be recommended. Most roofers won’t repair a subpar roof.

Roofing MaterialLife Expectancy
Asphalt Roll Roof10 – 15 Years
Built-Up Roofing (BUR)20 – 30 Years
3 Tab Asphalt Shingles15 – 20 Years
Architecture Shingles25 – 40 Years
Wood Shingles25 – 30 Years
Wood Shake Shingles35 – 40 Years
Corrugated Metal Roofing40 – 80 Years
Standing Seam Metal Roofing40 – 80 Years
Clay or Cement Tiles80 – 100 Years
Slate Tiles80 – 100 Years

Despite the life expectancy listed, all roofs require routine maintenance. This maintenance is generally needed every 5 – 10 years and includes a thorough inspection and sealing around roof penetrations or flashing as needed.

Gutters and Downspouts

According to NACHI’s Home Inspection Standards of Practice, home inspectors are required to inspect the gutters and downspouts during the general home inspection.

Problems with Downspouts

The SOPs recommend that downspout water must divert water at least four to six feet away from the home’s foundations. This is a fairly common issue that can have serious implications. If the downspout is directing water straight towards the home’s foundations, it has the potential to cause serious structural damage.

Just a few inches of rain can produce thousands of gallons of water runoff, and if the land surrounding the building has a negative gradient, or if the drainage is poor, this water has no place to go other than towards the basement, crawlspaces, and foundations.

Most gutter installers will install downspouts directly at the foundation. It’s up to the homeowner to install extension pipes, splash guards, or undergound piping to direct the water away from the foundation. Most homeowners are unaware of this until after the installers have come and are long gone.

Left alone, downspouts discharging too close to the foundation can cause localized flooding which can contribute to foundation problems after a few short years.

The downspout will also be inspected for a proper connection to the gutter and the roof structure, as well as damage that can be caused by weather conditions and impact from vehicles.

Downspouts should also avoid terminating onto other roof surfaces so they don’t cause secondary issues elsewhere. Discharging large quantities of stormwater runoff onto roof shingles will cause them to wear out faster and increase the likelihood of a roof leak forming.

Problems with Gutters

Home inspectors will examine the gutter system as part of their inspection, looking for potential problems such as clogging, rust, crack, holes, and leaks. Clogged rain gutters cause the water to overflow out of the gutter.

Sometimes, this water flows back underneath the shingles on the eaves, which can cause damage to the roofing materials and leaks in the attic. 

A clogged gutter is usually caused by a build-up of fallen leaves, dirt, silt, and it is easily removed. Homeowners should conduct roof drainage maintenance at least twice per year.

According to the Standards Of Practice, gutters should be adequately fitted and sloped towards the downspouts to prevent water runoff from being trapped in the gutters. If the gutters fail to prevent this runoff from exiting the gutters, water will collect inside the gutters causing stress on the piping to pull away from the house under the added weight of the water.

It’s a good idea to invest in gutter guard screenings to prevent gutters from becoming clogged with debris. This reduces the need for cleaning gutters which is safer for you since you won’t need to climb ladders or get onto the roof to clean the gutters.

Quality of the Installation

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A lot of the issues in our list can be attributed to a low-quality installation of the roof. A general rule of thumb is that a well-installed roof made up of high-grade materials should last around 20-30 years. However, that is not always the case, especially if there has been a faulty installation.

The inspector will check for poor quality workmanship during the installation, including the shingles, flashings, vents, gutters, downspouts, and the overall structure of the roof. Incorrect shingle placement and poor flashing installments allow water to enter the building via the roof, causing damage.

The inspector may look for low-quality nail patterns, incorrect level of overhang, poor shingle positioning, the quality of roof underlayments, and the integrity of the roofing structure.

Most installation problems occur in valleys where shingles are not properly interlaced or where improperly flashed. Valleys are where two roof lines converge. Often large amounts of water flow towards the roof valleys and even minor flaws can become a major roof leak over time.

Poor workmanship can also lead to wind damage. Wind can cause shingles that are not properly fastened to become loose or break. If the shingles are wind damaged, roof leaks can start around nail holes and along seams.

Problems with Roof Shingles

Most residential roofs are covered with shingles. Even if they were installed perfectly, they still succumb to wear and tear and can become damaged over the years.

If the home has asphalt shingles or wooden shakes, watch out or any evidence of them curling at the edge. This is a good indication that the shingles are coming towards the end of their usable life and would need to be replaced in the not so distant future.

The same can be said for evidence of buckling or blistering shingles. Large amounts of moss and lichen could point towards a decaying roof underneath and should be inspected further.

If shingles are missing from the roof or appear to be broken, this is bad news. Alarm bells should be ringing in your head if you see this, as it means that water may have been penetrating the roof for some time. 

It’s a good idea to have moss and other organic debris professionally removed. Never let anyone pressure wash your roof. Pressure washing a roof will do more damage than good. A professional roof cleaner will spray a non-toxic biodegradable cleaning solution on the roof and remove it with a soft wash similar to that of a light rain shower.

If some shingles are starting to curl or break, it’s safe to assume that other shingles are weak as well and could become wind damaged at any time. Remember, if 30% or more of the roof is damaged, a full replacement is the best option.

Problems with Chimneys

Home inspectors will perform a visual check of the chimney and will look to see if there are any large and obvious signs of obstruction. There are a wide variety of things that can cause blockages, such as dead animals, birds nests, leaves, branches, and so on. These blockages can become dangerous if they are left for too long as they allow toxic gasses, such as carbon monoxide, to build up in the home. 

Chimneys accumulate a substance called creosote, which is a by-product that collects when you burn wood and other substances. When the smoke travels up the chimney, the creosote sticks to the sides and can cause blockages as well. Unfortunately, creosote is a flammable substance and must be removed regularly with routine chimney maintenance. 

IF a home inspector sees a buildup of creosote on the flue walls, a recommendation should be made to have the chimney flues cleaned and inspected by a chimney sweep.

Older homes are likely to have brickwork and masonry issues which could cause a safety hazard. Neglected chimneys will crumble and eventually collapse if they aren’t given enough maintenance. Chimney joints can be repointed to sure loose bricks and degraded masonry joints between bricks.

Masonry chimney caps are prone to cracking which also leads to water intrusion that can damage the flue. Many older chimneys have open flues that allow rain to enter the chimney and potentially rust out the damper door. Most of these chimneys have missing rain caps and vermin screens.

Issues with the Roof Flashings

The roof flashing is one of the most important aspects of the roof when it comes to keeping water out of the house. If the flashing is installed properly and still functions as it should, rainwater will be directed away from the vulnerable areas of the roof and into the drainage system.

If the flashings become damaged, the likelihood of a leak drastically increases. Home inspectors will pay close attention to problem areas of the roof such as valleys, chimneys, skylights, and dormers. If the flashings are inadequate in any of these locations the home inspector will note this on their report.

Step Flashing

For rooflines that but up against brick masonry walls, we commonly see problems with step flashing. Step flashing is the practice interlocking pieces of metal flashing folded into the mortar joints in the brick masonry. Often the step flashing doesn’t extend up the wall high enough and doesn’t overlap enough to shed water properly.

Kick-out Flashing

For rooflines that but up again siding, the flashing should have a piece of kick-out flashing along the wall. This kick-out flashing is used to shed water away from the siding. This flashing is often not present particularly on older houses. Oddly, even in roof replacements on older houses, roofers fail to install it with the new installation.

Drip Edge Flashing

Drip edge flashing is another flashing that is used in roofing to protect the fascia boards. This flashing is laid over the transition between the fascia and roof and help support the overlapping lip of the shingles.

The drip edge flashing also helps stormwater runoff flow into the gutters and not behind the gutters. The back wall of the gutter piping should fit directly under the lip of the drip edge flashing.

Encroaching Vegetation

As part of their inspection of the exterior of the property, the home inspector will assess nearby vegetation such as plants and trees that encroach too close to the house. 

Fallen trees and broken branches can cause significant damage to the roof of a property. In addition to this, leaves that for from the trees can clog up gutters, downspouts, and chimneys, causing a knock-on effect of several other issues. If leaves are left on the roof for too long they can lead to mold and the deterioration of the shingles on the roof.

In addition to this, if there is a low hanging branch near to the house, there is a chance it could wear down the shingles or break the shingles, stripping off the important layers of asphalt and compromising the integrity of the roof structure.

According to both ASHI and NACHI standards of practice, it’s recommended that large trees and branches should be between eight and 10 feet away from the structure. This is the help protect the roof and to prevent moisture damage to the foundations caused by the tree’s long-reaching roots.

Indications of Roof Leaks

As you can see from our list, the majority of roof issues that we have raised surround some form of water damage or leak. This is for good reason, as water damage in the home can be devastating. 

According to industry estimates, the annual cost of insurance companies from water damage is around $2.5 billion, and the average home water damage claim is roughly $7000. This is why home inspectors keep a keen watch for any indications of leaks throughout the property, especially in the roof. Here are some common signs that the roof may be leaking:

  • Missing, cracked or damaged shingles
  • Water spots or water stains in the interior of the roof
  • The presence of mold or mildew
  • The pooling of water on the roof
  • Inadequate flashings/improperly sealed valleys
  • Ice dam build-up
  • Condensation in the attic

Roof leaks often start slowly, which makes them hard to notice as the attic is one of the least frequented rooms in the whole house. If these leaks go undetected for quite some time, they can cause considerable damage throughout the property and leave you with a heft repair bill later down the line. Not something you want from your new house.

Lack of Overall Maintenance

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Even though the roof is a particularly difficult area of the house to clean, it’s important to conduct regular maintenance to make sure that everything is in full working order. As mentioned, the roof is the home’s first line of defense against the weather, and if one or more of the aspects of the roof has issues, it will likely result in some form of water penetration to the home.

Not only that, but taking good care of your roof goes a long way towards maintaining the value of your house, saving you thousands of dollars in repair bills, and making the sale process a whole lot easier when that time comes around. The home inspector will be on the lookout for any signs of poor quality maintenance on the roof, such as:

  • Damaged gutters
  • Loose flashing
  • Missing and damaged shingles
  • Tree branches, leaves, and other debris on the roof and in the gutter
  • Rust
  • Mold and mildew
  • Neglected chimneys
  • Ice dam formation

Signs of Pest & Other Animals

If there are problems with the roof, such as missing shingles or an open chimney flue, there’s a chance that the homeowner could be welcoming a whole bunch of unwanted guests into the attic. In general, the roof and attic space is a pest’s paradise. It’s dark, cool, and offers plenty of food in the form of textile and wood. Here’s a list of some of the most common pests that can be found in the roof and attic space and what that means for the home inspection:


Birds can nest in several places on your roof, and even your chimney. While this may not seem like a problem at first, bird’s nests can cause clogs in gutters, downspouts, and chimneys. On top of this, most species of bird have acidic droppings which can damage key support structures and rot the shingles on the roof.


Nobody wants to see vermin in a house they’re about to buy, but they are far more than just an unpleasant sight. Rats and mice burrow through your roof and can chew their way through insulation, pipes, and even your electrical system. This presents a risk of electrical fire and structural damage, and that even before we get to the diseases they carry!


Certain species of bees love to build their hives on roofs. If they can make their way through the shingles they will start to build their new bee colony which can cause damage to the roof structure, especially if left unchecked. Carpenter bees will bore holes in wood facia to set up hives inside the eaves.

Termites and other wood-eating insects

Termites are the number one enemy of homes in the USA. They are known as the silent destroyer, quietly eating away at key support structures such as wooden joists and load-bearing walls. The roof and attic space is a great place for termites to feed, so home inspectors will be on the lookout for any evidence of these pests.

Termites will often feed through the floors, walls, and attics. While they live underground, they travel to and from through mud tubes. They can construct elaborate tunnels inside walls and may never be noticed unless you are trained and know what to look for.

For more information on common and major issues detected in home inspections, see our articles Common Home Inspection Issues & Their Repair Costs and 7 Major Home Inspection Issues Home Inspectors Report


While a home inspector can pick up on the vast majority of these issues, they are not obligated to determine the structural integrity of the roof or to give you an estimate on its potential longevity. 

If you want to receive a more detailed assessment of the roof then you need to hire the services of a dedicated roofing expert or a structural engineer. They will be able to give you a more thorough analysis of the roof, which can come in handy if you suspect the property may have issues in this area.

Thanks for reading!

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Hubert Miles

I've been conducting professional home inspections since 2002. I'm a licensed Home Inspector, Certified Professional Inspector (CPI), Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.
DISCLAIMER: The content published on HomeInspectionInsider.com is not professional advice. You should consult with a licensed professional and check local permit requirements before starting any project.
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