Will a Metal Roof Cause Mold?

by | Apr 28, 2022 | Roofing, Water/Mold Damage

If you’re considering the upgrade to a metal roof, then you’re likely curious whether or not it’s prone to mold build-up.

After all, once you’ve got a mold problem on your hands, it can be difficult, time-consuming, and expensive to fix.

In short, metal roofing can cause mold due to trapped water vapor. But there are ways to prevent, or at least reduce the risk of mold build-up.

So, this article will discuss everything you need to know about metal roofing and mold – helping you decide whether it’s the best roofing material for you.

If you’re looking for a roofing company in Danville, Kentucky, then contact the team at Jacob’s Ladder today for a quote.

Call (859) 379-9137

It’s all about the installation

Typically, metal roofs should not cause mold. However, often, many contractors and roofing companies cut corners to save time and money. Unfortunately, the result is a no moisture barrier, causing a build-up of mold and rust.

Some contractors install brand new metal roofs on top of old asphalt roofing with no barrier for moisture or strapping. Therefore, when it gets hot or cold, the roof will sweat and the moisture has nowhere to go.

Now, you can install a metal roof on top of existing asphalt shingles, but this must be done correctly with room for the roof to breathe and what is known as a moisture barrier (alongside other specifications).

A metal roof showing signs of mold has likely already reached a stage beyond repair. Or, at the very least, a very expensive repair job (this is because the metal underneath has already rusted and the mold has spread).

How to eliminate the build-up of mold for your metal roof

Whether installed over existing asphalt shingles or not, there are various things you/a contractor can do to eliminate the build-up of rust and mold for your metal roof.

For example:

  • Work with an experienced and reputable roofing contractor
  • Ensure a waterproof membrane is installed
  • The use of proper screws and washers prevents leaks
  • Reduce condensation

We will now explain each of these pointers in more detail below.

Work with an experienced and reputable roofing contractor

Firstly, you should not try to install a metal roof yourself, unless, of course, you have the required experience.

Typically, you should look for a roofing company that specializes in metal roofing, such as the team at Jacob’s Ladder. Choosing a reputable company is a sure-fire way to ensure a quality job that will last.

If you’re unsure, you should ask for testimonials, proof of existing work, and a quote.

A good roofing contractor will know what they’re talking about, and this should come across in their communication.

Ensure a waterproof membrane is installed

As previously mentioned, a lack of a waterproof membrane is one of the main culprits when it comes to mold on metal roofing.

There needs to be space for the roof to breathe and disperse moisture correctly. If not, then you will suffer not only mold issues, but also rust. This is especially true if you live in a coastal area, such as near the beach where there is lots of saltwater in the air.

The use of proper screws and washers prevents leaks

Believe it or not, there are special screws and washers that should be used for all metal roofs.

These neoprene washers and special screws are not only more UV resistant than standard options, but also help protect against leaks. But these screws should only be installed in the high points at each rib and below the strappings.

Reduce condensation

It’s no secret that a build of water vapor and condensation causes mold. So, if we can eliminate, or at least reduce condensation, then we can effectively prevent a build-up of mold.

For a metal roof, condensation is better managed by insulating a roof, so panel temperature never reaches the dew point. Furthermore, other insulation options such as fiberglass are available to help keep the metal roof below the dew point.

Contact a professional to install your metal roof to prevent mold entirely

Having a metal roof does not mean you will have a mold problem. But if your roof is installed incorrectly, then you’re likely to suffer a series of problems, including rust, mold, and the build-up of other bacteria.

So, choose a reputable metal roofing contractor, and you’ll enjoy your brand new metal roof for years to come, all with little to no mold issues.

Contact Jacob’s Ladder today to get started.

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