Have you heard horror stories about metal roofs rusting or leaking within a few years? Are you worried that your metal roof installation caused serious, costly structural damage to your roof?
At RoofSmart, we have seen the damage that can happen when a metal roof installation goes wrong. We recently helped a customer whose metal roof was leaking due to poor installation techniques and using a metal panel style that wasn’t suitable for the pitch of their roof.
We resolved the issue by replacing some panels and adding ice and water shield underlayment for extra protection in that area.
In addition, we brought in a sales expert from Exterior Metals (a local metal manufacturer) to discuss common problems he has noticed with metal roof installations in the Greater Seattle area and how to avoid them.
In this article, you’ll learn:
- 4 common issues with metal roof installations
- How to avoid or fix these issues
- How to know if a metal roof is right for you
By the end, you’ll understand the risks of installing a metal roof and, most importantly, how to avoid damaging your roof (or setting your roof up for failure down the road) during installation.
How can a metal roof installation go wrong?
Sometimes mistakes or accidents happen during a metal roof installation. Some are no big deal, but others can cause extensive damage.
Before your installation begins, it’s crucial that you learn about the potential risks so that you know how to avoid them and save yourself a lot of extra money and stress.
We asked our source at Exterior Metals what the most common issues with metal roof installations are. Here’s what he had to say:
1.) Poor Installation Techniques
The biggest issue that homeowners face when getting a new metal roof is poor installation. Metal roofs require more expertise and skill to install than asphalt shingles, so not everyone can install them.
Improper installation techniques can cause leaks or other problems in your roof down the road, costing you more money on an already expensive investment.
This is exactly what happened to the customer we described in the introduction. They hired a company to install their metal roof, but they ended up having a leak due to poor installation techniques and had to hire another roofing company (us) to come fix it.
They had clear evidence of a bad leak:
Leaks are very common in the Greater Seattle area due to the consistent rainfall. They can often lead to more extensive damage like mold or rotting wood.
How can poor installation techniques be avoided?
The best way to avoid poor installation is to vet your roofing contractor. You need to find an experienced roofing professional who can demonstrate that they’re qualified to install a metal roof.
This might seem obvious, but time and time again we get calls from homeowners who need a repair or replacement much earlier than they should because their previous roofing contractor did a bad job. An experienced roofer will do the job right the first time.
2.) Uneven Roof Deck
Some homes have wonky, crooked roof decks. Typically, this is because the house is old, and different (and usually outdated) materials and techniques were used when it was first built.
An uneven roof looks particularly bad with metal because the smooth, flat panels make any dips or bumps very obvious. Aside from looking bad, if not sealed or fastened properly the roof can leak, leading to extensive damage.
Here's an example:
How can an uneven roof deck be avoided?
This can be a difficult problem to fix. Your roofing contractor might have to add shims in the low spots or redo parts of the roof deck depending on how bad it is. This is where having a qualified roofing contractor comes in handy because they’ll know how to deal with this issue.
3.) Oil Canning
Oil canning is when the metal panel looks wavy and distorted. This is an inherent characteristic of the metal panels and the good news is that it does not cause any damage to the roof. The panels will still function properly. However, some people do not like how it looks.
Oil canning can sometimes be caused by poor installation or an uneven roof deck. It can also just happen without explanation. Because there are so many things that can potentially cause oil canning, the manufacturers do not accept it as a valid reason for rejection.
Here’s an example:
How can oil canning be avoided?
Unfortunately, once the panels are on the roof there’s not anything you can do about it. But, if you are worried that oil canning might happen and want to take precautions against it, our source from Exterior Metals recommends choosing metal with striations.
Striations are lines running up and down the panels, acting as an added design element. This helps to hide the appearance of oil canning.
4.) Using Incorrect Products
If you have an inexperienced roofer, they might use the wrong products. For example, they might use the wrong type of panel or install material that cannot be used on your roof’s slope (like the example we gave in the introduction).
Another potential issue is using the wrong kind of underlayment. Roof underlayment with a layer of granules on top can’t be used with metal panels because it can cause damage to the roof. It is meant for asphalt shingles.
Metal expands and contracts as the temperature changes. When this happens, it can rub against the granules and scratch off the primer coating.
Once that protective coating is gone, any water that gets under the metal panels can cause rusting. In a wet, rainy area like Seattle, leaks and rusting are a big concern.
If there is a place for water to get into the roof, it will. And, chances are that if your roofer was using the wrong products they probably also did a poor job with the installation, creating an opportunity for leaks. This means you’ll have to repair or replace your roof much sooner than anticipated.
How can using incorrect products be avoided?
The best way to avoid this is to find a roofing contractor who has lots of experience installing metal roofs. In other words, you should feel confident that your roofing contractor is knowledgeable about metal roofing. An experienced roofer will know exactly which materials they need for the job.
Need help finding a roofer who is reliable and trustworthy? Download our Qualified Roofer Checklist.
How do I know if a metal roof is right for me?
To help you decide if a metal roof is right for you, consider these questions:
- What is your budget?: The average metal roof installation in the Greater Seattle area costs $50,000 to $60,000. It’s important to be aware of your budget and consider if the benefits are worth the investment for you.
- How long do you want to live in the house?: Metal roofs usually last for about 50 years. So, if you’re going to be in your house for a while it can be a good investment. And they add value to your home, so if you decide to sell you’ll still have a good quality roof on it.
- Have you considered the benefits of a metal roof?: This article only focuses on the negative aspects of metal roofs. While it’s definitely a good idea to be informed about potential issues you might face, we also encourage you to consider the benefits of a metal roof before you make your final decision. For example, metal roofs are durable, long-lasting, and low maintenance.
Avoid Costly Repairs by Choosing the Metal Roofing Contractor
At the end of the day, a poorly installed metal roof can lead to costly repairs, structural damage, and frustration. This is especially true in areas like Seattle, where heavy rainfall makes proper installation even more critical.
Now that you understand the four most common issues that occur with metal roofs and how to prevent them, you can confidently move forward with your roofing project.
Your next step? Work with a knowledgeable, experienced contractor who specializes in metal roofs. To start the search, read our article “The 8 Best Metal Roof Replacement Contractors in the Greater Seattle Area”.
If you need guidance, RoofSmart is here to help—our team ensures your roof is installed correctly the first time, protecting your home for decades to come.
Schedule an inspection with us to learn how we can give your roof top-tier protection.
