How to fix a leak in a metal roof

If you’re having trouble with a leaking metal roof, there are a few things you can do to solve the problem. In this article, we’ll discuss the common causes of leaks, Equipment you’ll need, and how to repair a leak using butyl tape. We’ll also go over the various techniques you can use to make your roof waterproof again. And, we’ll also go over some of the most popular leak repairs that you can try.

Contents

• 1 Common causes of a leaking metal roof
• 2 Equipment needed to fix a leaky metal roof
• 3 Common places for leaks on a metal roof
• 4 Repairing leaks with butyl tape

Common causes of a leaking metal roof

A leaking metal roof can ruin valuable items and can be costly. When left unchecked, water can collect and cause building components to rust and rot. Standing water inside a building can also encourage microbial growth. If you catch these problems early, they can be repaired or replaced without further damage. This article will discuss common causes of a leaking metal roof, and how to prevent them.

A leaking metal roof may be caused by many different problems, but the most common is defective flashing. Flashings are thin pieces of metal installed on the edges of a roof. These flashings are designed to prevent moisture from entering joints and additions. Installing them correctly is crucial to preventing leaks. A leaking metal roof can also be caused by a failed sealant. Whether the flashings are made of metal or plastic, you should have them professionally installed to prevent water damage and costly repairs.

Equipment needed to fix a leaky metal roof

Before you begin repairing your leaky metal roof, you need some basic equipment. You will need a drill with screw drill bits and a hammer. You will also need rubber-to-rubber contact cement and a paint roller. You should also have a utility knife and a cutting tool for scraping off the damaged fiberboard. Having these tools on hand will save you time and strength when you’re working on your roof.

When you begin repairing your metal roof, you should take care to properly protect any pipes and air vents. Pipes that come through the metal roof need to be protected from water, so they should be fitted with stack flashing. Most stack flashings are rubberized materials that sit flat on the metal roof and squeeze around the pipes. The movement of the metal roof will test the sealant. Be sure to carefully check all parts of your metal roof before you begin.

Common places for leaks on a metal roof

One of the first things you should do if you suspect a leak is to lift the panels surrounding the spot where the leak originated. When looking for the source of the leak, you should be aware that water will often move upwards and sideways on metal roofs. As such, look for signs of dents, punctures, and loose metal panels. These signs can indicate that there is a problem with the roof sheathing.

Another area where a metal roof might develop leaks is around the curb. While flashing is installed all around the curb, water will still get through at some point – especially if it’s situated on an uphill slope. Your roofing specialist should check this area regularly. Leaks in a metal roof can also happen at seams. When panels overlap, they must be sealed before they are installed. Otherwise, water will leak uphill against gravity and surface tension.

Repairing leaks with butyl tape

When you’ve got a leak, but don’t know what to do, you can repair it with butyl tape. This tape is a versatile solution for a variety of purposes, including RVs and roof repairs. Its advanced adhesive and waterproof properties make it an excellent choice for a variety of applications. You can use it on windows, water pipes, and glass in addition to roof repairs.

Butyl tape is widely used for waterproofing projects, such as kitchens and basements. It can be made thicker to increase strength, stability, and airtightness. Apply pressure to the butyl tape to help it conform to the leak area. If any adhesive oozes out of the seam, use a plastic card or knife to cut it off. After applying the tape, wipe it with soapy water to remove any residue.

Every year we provide framing systems that allow a new metal roof to be installed over an existing metal roof. Sadly, in many cases the roof is being replaced not because it had reached the end of its useful life but rather because it had been improperly repaired. These repairs take many forms but most are along the order of tar, caulk, or other exotic conventional roof coating material that is rolled, sprayed or smeared on the metal panels with the promise of a long term “fix” to the leak problem.

Metal roofs are the longest life, most maintenance free roofs on the market, but any roof can and will eventually develop a leak. Metal roofs however are a specialty in and of themselves and contractors that do not specialize in metal roofing will frequently make incorrect and/or seriously damaging repairs. Another important aspect is that most newer metal roofs have 20- to 40-year finish warranties. Improper repairs can easily void these warranties!

Assuming your metal roof has a leak where do you start?

1. Where is the roof leaking? What unit or point in the building has the leak appeared? Approximately how far from the eave going toward the ridge and from one building end along the eave is the drip showing up? Remember metal roofs always have a pitch and water always runs downhill, so the leak is typically at that point or upslope from that point.

Ok, I have the information I need, now who should I call?

1. First and foremost, call someone who specializes in metal roofing. The typical “roofing contractor” may be highly skilled with shingles, built-up or single-ply systems but metal roofs are totally different. Metal buildings commonly have the manufacturer's logo and name on the peak or somewhere on the building. Call them for a recommendation; they will have a network of builders and installers they work with. This will also protect any remaining warranty you may have. Don’t inadvertently void your warranty.

2. If the building is too old or there are no markings remaining, I would suggest any local metal building contractor or metal building erector. Another great resource is the Metal Building Contractors and Erectors Association (MBCEA). This is a group of qualified metal building specialists that work continuously to maintain the highest quality of workmanship.

But my roofer friend says he can handle the job. No problem, right?

1. Ok, maybe, but ask a lot of questions first. A roof repair does not mean you put caulk, silicone, tar or other foreign material on the metal panels! If a fastener has failed, it should be replaced with a new over-sized long-life fastener not covered with goop! Caulking or coating fasteners, panel side-laps or panel end-laps is not a fix - it is how you significantly shorten the remaining life of your roof!

2. Remember, metal roofs move constantly. It doesn’t matter if they are screw-down or standing-seam, they move. Because of that, metal roofs also have their own specialized group of accessories for pipe penetrations, roof openings, snow retention and other roof-mounted equipment. Never allow another contractor - i.e.: plumbing, electrical, mechanical or other profession - to penetrate your metal roof. They don’t understand them and they will not do it correctly. They also not properly trained on how to walk on a metal roof. Uncontrolled foot traffic can do serious damage to your roof.

Conclusion

1. Understand that if you have a metal roof, then you have a top-of-the-line roof system. It requires a company that specializes in metal roofs to repair it if you have a problem. Get the right guys to guide you on repairs. Ask questions as to how they intend to make the repair; have them provide pictures.

2. Caulking or coating over problems on a metal roof will quickly cause a myriad of other problems: some voiding your warranty, others creating life-shortening and double expense problems for your roof.

3. If you need to modify the roof, add openings, equipment, etc., get a specialist; shortcuts here are not good. Metal roofs have specially designed accessories that allow for movement and proper sealing. Conventional roofing products are not designed for use on metal roofs.

4. If the roof truly has reached the end of its life, replace it with another metal roof. That’s what the building was designed for. Use a retrofit system that is fully engineered and can document that it will comply with the latest building codes for wind and snow loads. This will enhance your insurability and resale. It will also give you the lowest, long-term cost for your investment.

5. Check out those tax credits, section 179 of the tax code may allow writing off up to $1 million. This will make the whole retrofit process much easier.

Dale Nelson is the president and co-founder of Roof Hugger LLC, which is a division of the LSI Group that includes Logan Stampings and BPD Clips. Founded in 1991, Roof Hugger is a nationally recognized manufacturer of retrofit framing systems for metal-over-metal reroofing. Nelson, who has played instrumental roles in a variety of trade associations and efforts to further the reach of the metal construction industry, began his career in 1973 in the general contracting field. For more information about Roof Hugger, visit www.roofhugger.com.

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