• Sam Miller

Metal Roof Repair How To's

Updated: Jun 25, 2019

I wanted to write about some of the basics of repairing a leaking metal roof using coatings and what it takes to obtain a manufactures warranty through a certified contractor.

Metal roofing is Strong and LONG LASTING, and in most cases pleasing to look at. It can and will offer years of service on your commercial building with a little maintenance.
With all that being said, there are some drawbacks. Here are a few we encounter on a regular basis.

1. Rust creating pin holes
2. Gapping seams
3. Loosening fasteners that are backing themselves out or broken inside the deck

These are all treatable conditions with some specialized knowledge products and experience.

First the deck surface MUST be clean and dry. The best way to accomplish this is by power washing using at least 2-3K PSI power washer and chemical cleaning agent designed for metal roofing and then allowed to dry.

All repairs must then be addressed this is where experience comes into play, you have to know where to look and what to look for (example ) around HVAC units, roof penetrations. After all basic repairs are done you have to address ALL the fasteners, in my experience this is where the majority of a problem leaky roof lie. Now is where you need specialized products like Butyl caps, or Acrylic or (Silicone sealent if ponding water is present, rare if roof has a nice slope).

Next up is vertical and horizontal seams. Now is where knowledge is of use these cannot be treated the same way. Horizontal must be treated in what’s known as a three course method. First you must apply a generous amount of flashing grade compound, then enbed typically a 6” wide polyester cloth, then cover with a second coat of flashing grade. For verticals in some cases you can simply use Butyl tape or a Butter Grade flashing compound.

Now we come to the meat and potatoes of metal roofing coating repair.

Priming and coating. To obtain up to a 25 year limited warranty for your roof repair you have to have the deck Primed (if rusty) and up to several coats of high quality commercial grade roof coating. The quantity and thickness of each coat depends on how long the warranty applied for.

I know this might sound a little daunting and it is IF you were going to tackle this project on your own but luckily you don’t have to we are here to help.

Sam Miller, President
Kingdom Roofing and Sealcoating Inc.

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