How to Fix a Metal Roof Leak

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The fact that metal is the lightest roofing material makes it your best roofing choice. So naturally, you ought to know how to fix any leaks on it to maintain its pride.

You can fix your roof by;

  • Replacing the screws
  • Installing a roof coating over the present metal roof
  • Installing a spray foam
  • Removing the old metal roof and replacing it with a new one

Don’t struggle again with fixing your metal roof while we can enlighten you on every basic detail you require to fix it. Let’s teach you how to locate a metal roof leak, its causes, and its methods, and give you a step-by-step guide to fix your roof.

How to Locate a Metal Roof Leak

Most metal roofs normally have some usual areas where leaks occur, and searching those areas first is the best way to locate leaks. Below is how you should look for metal roof leaks.

On the Transitions

In the transition areas, you should focus mainly on minor details, especially valleys. Common transitions are:

  • Pitch changes
  • Valleys
  • The transition from one roof plane to another of identical material
  • The transition from one roof to another of a different material

what do you look for:

  • Missing or loose screws. Also, check the alignment to see if it’s missing some screws
  • Gaps of butyl tape or the sealant
  • The orderliness of seams on the place the metal roof panels meet another
  • Gaps or untightened trims on pieces

The Termination Details

Some common terminations include:

  • Ridge cap
  • Counter flashings
  • Hip cap
  • Coping cap on the wall

On the terminations, you should look for the following:

  • Any loose or absent pieces of a hip cap, ridge cap, or coping cap
  • Ensure there is no water running under the caps
  • Check the counter flashing where the roof stops into the parapet wall

Ensure you inspect when the roof doesn’t have snow or ice, and the panels are dry.

The Roof Penetrations

Some common penetrations are:

  • Skylights
  • Chimneys
  • HVAC curbs
  • Plumbing vents

On the penetrations, you should look out for the following:

  • Any gaps in metal trim at the corners of HVAC curbs
  • Any broken seals on the flashings
  • Compromised sealant around the flashings

The Body of the Roof

If you’ve missed leaks on the roof’s penetrations, transition, and termination, the body is the next probable place. You confirm these leaks by checking for the following:

  • Rust in holes
  • When a standing seam roofing panel slides from contraction and expansion
  • Punctured holes in the roof
  • Loose, extremely tight, or missing screws

Some advice is to always start with the easy parts to locate. Where you can’t easily reach, use binoculars.

It’s rare to miss your leak from these areas. However, if you can’t locate one, seek the assistance of an expert.

Causes of Metal Roof Leaks

Metal roofs have been known to be durable, but these several causes can lead to leaks.

  • Metal surface rust. Rust might not necessarily mean leaks, but again shouldn’t be left untaken care of, or it can be the reason for leaks through holes. You can use a rust inhibitor to prevent rust from spreading on your roof.
  • Deflection. The roof might leak when metal panels are crimping or creasing or have holes. The deflection is mainly caused by foot traffic. The deflection causes water to stagnate, which in the end, causes roof leaks.
  • Punctures. Punctures and tears on HVAC units are caused by dragging and hitting on metal roofs. Damage to these units causes serious roof leaks through creases, crimps, and holes.
  • Movement. It causes leaks when you use repair materials that aren’t flexible, and hence the patch is immovable, so water holds there. Instead, you should use materials that allow your metal roof to move, thus allowing water to flow effectively.
  • Open laps. When they’re not properly installed, seams and metal panels lift and leave an open area where water penetrates.
  • Missing roof parts. With time, parts of roofs fall off from wind, deterioration, or debris. Any openings like gutters, edge metals, foam closures, and downspouts will likely allow water in, hence leaks.
  • Incompatible materials. The use of these materials causes corrosion and hence leaks. Therefore ensure you don’t use these materials on your roof.
  • Fastener issues. The metal panel typically has two attachments– the clips and fastener with rubber washers. Clips hold to purlin, and the fasteners are covered when the metal laps on metal panels get seamed together and have a sealant below.
    Fasteners with rubber washers are placed at a distance of 2 sq ft. with time, fasteners get off and leave behind holes between the metal and rubber washer, leaving behind open water penetration areas.

Other Causes of Metal Roof Leaks

Here are several other common causes of metal roof leaks:

Metal Roof Screws

Metal roofing screws are the number one cause of leaking roofs. The primary duty of screws is to compress the rubber washer to roof panels to prevent any from getting into the roof. However, if these screws are installed incorrectly, they cause major roof leaks.

For instance:

  • Over-inserted screws. If you over-press the screws, they break the rubber washer, which weakens your seal
  • Poorly inserted screws. This means the rubber washer is not compressed, so your screws and metal panel can’t create a gasket
  • The wrong angle. For example, a rubber washer can’t stay flat on the metal panel. The screw can’t completely seal in that angle

Also, correctly installed screws can degrade, losing their seal, which becomes challenging to separate leaking screws.

The Stack Flashings

Most of the stack flashings are rubber sealants that are flat on metal panels. They usually seal the roof and squeeze the pipe area to seal any penetrations.

However, expansion and contractions often destroy seals made by stack flashings, thereby causing leaks.

Different Methods to Fix Metal Roof Leaks

If you’re looking for ways to fix your metal roof, we’ve provided a few options that can be useful to you:

  1. Replacing all screws and fasteners
  2. Installing spray foam on the roof
  3. Installing a roof coating over the metal roof
  4. Using a metal roof sealant
  5. Replacing the entire roof

Replacing All Screws and Fasteners

Damages on screws and fasteners are a major cause of your roof leaking. When the screws back out, they offer a passage for water into your home.

Therefore the solution is; anytime you spot any of these backings out, then you should remove them and replace them with new ones. Unfortunately, this solution is not easy since it’s tiring to inspect screws and fasteners one by one.

Installing Spray Foam on the Roof

Installing a polyurethane foam spray is one of the greatest options for repairing your leaking metal roof. The reason is that you can install it over the existing metal roof panel.

Other benefits are:

  1. Increased-R value. The R-value of spray foam is 6.5 inches in thickness. This R-value reduces the energy costs of your metal roof for the period it lives. Spray foam easily pays back its installation cost by the energy cost it saves over time.
  2. Closed-cell insulation. The closed cell properties of a spray foam ensure that water remains intact when there is any damage, like cracks. Unlike in the case of open-cell insulation, where when there is a crack, water moves all over, thus affecting a larger area.

Install a Roof Coating Over the Metal Roof

You apply coatings by spraying or rolling the material over your roof. If you’re using an elastomeric coating, you can easily apply it on your present roof.

An advantage of using coatings is there are only a few damages sustained. The reason being you only remove the damaged areas.

To install a roof coating, you need to prepare your roof to accept the coating by:

  • Replacing any metal roof system present that can affect your coatings adhesion
  • Thoroughly cleaning your roof
  • Using rust inhibitor primer
  • Adding more coat on screws and fasteners
  • Doing adhesion tests with several coatings
  • Adding more coatings on seams

Note that different coatings come with different warranties. You can determine the warranty duration by the thickness of the coating.

For example, a 10-year warranty is 20 ml of coating on your roof, and a 20-year warranty is 30 ml of coating installed on your metal roof.

Using a Metal Roof Sealant

Sealant is an effective way to fix metal roofs, especially if it has high polyether solids or silicone. The advantages of sealants with polyether are they blend nicely with metal roofs and have fantastic adhesion to metal surfaces.

Sealants with silicone are great in high-temperature areas. They’re even better when they’re a dark UV-absorbing color. 

Replacing the Entire Roof

As much as this is expensive, it can also be an option for fixing leaks on your metal roof. For instance, removing and replacing a new metal roof can cost roughly $15 and $20 per square foot.

How to Fix a Metal Roof leak – Step-By-Step Instructions

A metal roof repair is delicate since you don’t want to make matters worse, assuming you’re fixing it. This is why we’ve prepared the steps below, so you don’t mess up your metal roofing.

  1. Clean the affected area
  2. Scuff the metal
  3. Measure the metal roof repair area and cut a patch
  4. Install and secure the patch
  5. Paint the patch to match the roof

Clean the Affected Area

The first crucial step is cleaning. Regardless of the reason for the holes causing the leak, you should thoroughly clean the area.

You can use cleaners to ensure your surface is clean and free of algae or any film. Ensure you wipe away the cleaner residue, so it doesn’t compromise the capability of your roof repair.

Scuff the Metal

After cleaning, use a wire brush to scuff your metal surface, where you will make repairs. Scuffing helps the sealant bond with the roof.

You should only use the wire brush on the area to be patched. If the scuffing goes beyond the area, the brush might remove the protective coating of your metal surface, causing deterioration.

Measure the Repair Area and Cut a Patch

Cut your metal roofing material according to the size of the area you’re patching. The patch should go at least 2 inches beyond the edges of the repair area.

After cutting and fitting the metal patch, ensure you round its corners with an emery cloth or file. This prevents sharp corners from forming an area to gather snow or ice.

Install and Secure the Patch

Apply a urethane sealant to the repaired metal surface, and maintain it inside the outline marked by the pencil. Apply repeatedly on the area to ensure no gaps at the edges.

Press the metal patch on the area tightly. Until you have a sealant, squeeze from the sides. If there are areas where the sealant is not squeezing out, it means there are spaces where water can penetrate. Therefore, apply more sealant on the gaps to ensure no spaces. 

Once the patch has been pressed on the repair area, fix it onto the roof panel using your pan head sheet metal screws.

  • Have the screws on a space of three to four inches around the patch
  • The screws need a distance of one inch on the edges so they apply uniform pressure to the edges and sealant
  • Have the screws long enough to hold the patch to the metal roof panel
  • Never screw a patch down on the roofing panels into the rafters or roof decking

After a secure patch attachment, use your putty knife to retool the sealant oozing from the edges. This ensures that the sealant securely seals the edges of your patch and avoids moisture coming through.

Allow the sealant to dry as instructed by its manufacturers. Most take one or more days to hold temporarily and about a week to cure fully.

Paint the Patch to Match the Roof

Lightly brush using your wire brush over the patch and the metal panel. Next, paint over the metal and to the panel’s surface below.

Ensure the sealant is fully cured before painting. Also, ensure the paint is suitable for the sealant you used.

Fix Your Metal Roof to Avoid Unnecessary Leaks

A metal roof is made to protect your house from external weather conditions, but when it gets damaged, you definitely can’t enjoy the inside of your home.

In addition, when a roof is not taken care of, holes will form, causing leakage.

When you’re fixing the roof yourself, confirm you have the right tools for the job like:

  1. Metal snips
  2. Wire brush
  3. Paintbrush
  4. Putty knife
  5. Cordless drill
  6. Emery cloth or a file
  7. Pencil
  8. Caulk gun

Contact an expert immediately if you can’t fix the roof from the above knowledge. You shouldn’t add damage to your already delicate metal roof.

Metal roof systems are strongly recommended to be reviewed yearly to catch problems before they develop further damage.