Exposed Fasteners: Leaking or Condensation with a Metal Roof

Exposed Fasteners: Leaking or Condensation?

May 20, 2017 | Filed under: Metal Roofing, Roof Repair, Roofing Answers, Roofing Help, Roofing Installation

I am not a huge fan of exposed fasteners for roofs on residential applications. Probably 80% of the questions I receive about problems with metal roofs pertain to these types of panels. That said, I am happy to help when I can.

I recently received the following question from Jane:

Q. I noticed my inside ceiling insulation was wet in a strip on both sides of the ceiling where it appears that the screws were put in in the metal roofing. Since I know nothing about roofing, I am 80, I started to put silver tar on the roof, but only put it on half of the roof because someone told me that I needed to calk around each screw because you could see where some of the screws were crooked. What kind of calk is the best to use? Have I ruined the metal roof with the tar I put on? Thank you for your help.

Here is my response:

A. Thanks. There is a chance that what you’re seeing in the attic is due to condensation forming on the screws. The condensation would be the result of moisture inside the home reaching the attic and not being properly vented out. The condensation forms on the screw tips because they are transmitting cold from the outside. One thing you might do is wait for a rain on a warmer day and, while it’s still warm outside, check and see if the screws seem to be leaking. If not, then I am guessing this is actually condensation. If it is condensation, try to increase the attic ventilation.

If you do decide to seal the screws (keeping in mind that one option is to replace the screws with new, larger diameter screws), I would suggest some sort of quality butyl or co-ether sealant. You should still be able to seal over the screws you have coated.

Good luck and be careful!

todd Miller

has spent his entire career in the metal building products manufacturing industry. He is president of Isaiah Industries, an organization recognized as one of the world’s leading metal roofing manufacturers. Todd is currently Vice President of the MRA (Metal Roofing Association) and a Past Chair of MCA (Metal Construction Association). Through his website, he strives to raise the bar on standards and practices to provide property owners with the best possible products for successful roofing projects.

You may pull quotes from this article provided you include a link back to the original article on this site. You may not reprint this full article, or even a significant amount of the article, without explicit permission. To gain permission, click here.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

8 factors

8 Factors That Influence The Cost of a Metal Roof

Find Out

Before You Call a Roofing Contractor

dial cellphone

Unfortunately, most roofing contractors come in, measure, and simply give you a price. Learn more about what you want and what you need in a new roof, before you invite the contractor into your home. My Roofing Profile Selector is easy to use, and it will help you find the very best roofing solution for you and your home.

Get started