HOW TO REPAIR A METAL ROOF

Metal roofs are very durable with a long expected lifespan; however, due to storm damage or rust, they may occasionally need repair.

If you suspect that there is a leak in your metal roof, then you may need to make a repair. Your goal is to make any repairs before the water damage affects the structural integrity of your roof.

First, you must decide whether the entire section of the roof must be replaced. If that’s the case, you may need to call a roofing specialist who can remove and re-install a metal sheet on the roof of your building or home.

However, in most cases, the leak in your roof can be fixed by making small repairs. In short, metal roof repair can be a weekend DIY repair project.

Storm Damage

The expected lifespan of a metal roof – especially a steel roof – can be anywhere from 30 to 50 years for any building.

However, all metal roofs have seams where the pieces of metal fit together. It’s at these seams where most of the damage from rain or snow can occur.

Water damage that’s allowed to accumulate over time can lead to rust forming on your roof, which can then result in the formation of holes and leaks in your roof and damage to the building.

Materials

For metal roofing repair, you will need the following materials:

Once you have obtained these products, you will need to follow a five-step guide on how to repair metal roofing for a building.

Step One: Survey the Roof

If you suspect that there is a leak in your roof, you will need to get up on the roof with a ladder to determine the full extent of the damage.

Often, you’ll also see things like loose nails on the roof, a gutter that has been misaligned or patches of rust. It’s easy to fix these.

For example, just pull out and re-nail the loose nails. However, what you are particularly looking for are any holes or leaks. Rust is often a warning signal that a hole is nearby.

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Step Two: Fix the Rust Patches

Rust is a relatively common problem, but also one that requires quite a bit of manual effort to remove. You will need to remove the rust with a wire brush or a piece of steel wool. Once the rust has been completely removed, prime the surface with a metal primer and follow up with a top coat.

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Step Three: Fix the Leaks

The key to fixing any building leak is roofing cement. Roof cement can be made of different materials, including:

  • Asphalt (i.e. bitumen)
  • Plastic
  • Silicone
  • Polyurethane
  • Urethane

While it’s common for some roof specialists to use products like asphalt or plastic (which is made from ground up asphalt), the best option is urethane, which offers the best protection against the UV rays of the sun.

The problem with silicone material, for example, is that it allows UV light to penetrate, and that means it can break down easily.

Once you’ve selected the type of roofing cement that you are going to use on your roof, it’s time to apply it over the leaks that you have found.

You have two options here: if the roofing cement is from a can, you will need to apply it with a trowel or putty knife. If it is from a caulk-type tube, then you can apply it with a caulk gun.

The key is to smooth over any hole or damaged area with this roofing cement. Some roofing specialists prefer to apply one layer of roofing cement, lay over a thin layer of roofing mesh for added protection, and then cover that up with another layer of roofing cement for an extra-durable seal.

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Step Four: Reseal All Roof Seams

As noted above, the areas of the roof that are most susceptible to leak damage are where the seams of the roof interconnect.

As a result, your next step is to reseal all the seams and then to reseal all the edges along the flashing using urethane roofing cement. Pay particular attention to any ridges or valleys of your roof where the metal forms a new plane.

Also, look for parts of the roof around chimneys, vents or flashing where you suspect water damage could be leading to new holes or leaks.

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Step Five: Replace Any Damaged Flashing

While you are up on the roof, also look for any signs of damaged flashing. Again, this is important because the flashing helps to create a watertight seal between each overlapping region of the roof.  When you see any damaged flashing on your building, you will need to replace it.

flashing-to-the-roof

Choosing the Right Sealant

The choice of which roofing cement to use is an important one. Regardless of which product you finally pick, you need to be aware that this roofing cement will eventually deteriorate over time.

The choice of sealant is a big determinant in how fast it will deteriorate. Thus, it is important to keep in mind the quality of your products.

For that reason, many roofers will tell you that silicone sealants are not roof-worthy for your building. Silicone is a clear sealant that allows UV light to penetrate and breaks down easily.

This can cause cracking and dry rotting, which makes the sealant ineffective within a short period of time.

On YouTube, you can see videos of roofers demonstrating the effects of a silicone sealant – they can literally peel back the silicone and see the rust that has been accumulating under the silicone sealant.

If that’s the case, then the process of metal roof repair becomes slightly more complex; you will need to scrape off all the silicone, get all the rust off by grinding it down with a steel wire brush, and then overlay a bitumen or urethane patch.

So, the better choice is one that is pigmented (to better withstand UV rays), and those options are polyurethane or urethane-based.

A urethane sealant is preferable because it is more elastic and moldable than polyurethane. Thus, it can better fill in any cracks or gaps you may have on your metal roof.

Also, always make sure that the roofing sealant that you choose offers maximum UV protection, since UV rays are a big factor in the breakdown of any sealant layer.

When to Repair the Roof

The best time to make repairs to a metal roof is on a sunny day when there is no risk of any moisture or water interfering with your repair process.

Remember

The enemy of a metal roof is moisture, and you will need to take every step possible to prevent any water or moisture from causing future cracks or leaks.

Water that penetrates a sealant, no matter how strong, will lead to rust and metal damage much quicker than you might expect.

Inevitably, though, the time when metal roofs begin leaking is after a major storm or during the winter when hail or snow damage may have finally led to a hole or leak.

Thus, you will need to take every step possible to clear away any standing pools of water, remove any ice or snow, and then begin the repair work.

Safety Considerations

Any time you get up on a roof, you will need to take extra safety precautions. Do not go up on your roof during periods of high winds.

Wear safety gloves to protect your hands when scraping or grinding away rust. Make sure that you are wearing shoes with plenty of grip and traction to prevent any slips or falls.

And always make sure that the ladder you are using fully extends to the level of your roof. When taking materials up to the roof, it’s best to put them into a bucket or some other container so that you keep your hands as free as possible.

Conclusions

Even the most durable metal roofs, such as those made from steel, will need occasional repairs. This is especially true if you are living in an area with severe weather conditions, such as extreme cold or strong rain storms accompanied by strong gusts of wind.

By surveying your metal roof from time to time, you will be able to reseal and fix any leaks or holes that may be forming. The sooner you can fix these, the more you can preserve the full value of your metal roof.

When looking for potential holes or leaks, focus on the seams of the roof or any area where two overlapping pieces of metal form a new plane.

For most homeowners, repairing a metal roof is a weekend DIY project that can help to maintain the value of a home for decades.

Just always remember to use the highest-quality products, since this will guarantee that your repairs will last as long as possible and prevent future problems from happening.