Why is there foam in my gutter??

Today I received a call from a homeowner who had a GAF roof installed about 5 months ago by another local company. Every time it’s rained since the roof was installed, he finds foamy water in his gutters. He was a little concerned as to why this is happening and whether it would hurt his plants, so he called the company that installed the roof and was simply told “this is normal”.

Unsatisfied with this answer, he started calling around and reached me. In the few years I’ve been here, I’ve never heard anyone mention this issue. I apologized that none of our roofers were here at the moment for me to ask, but suggested he contact GAF directly.

Since I prefer to give helpful answers rather than pacify clients with “it’s normal”, I couldn’t just leave this alone even though he was not our client. I also felt it was important for me to know the answer for anyone else who may ask, so after some unfruitful searching online, I decided to ask our rep at Owens Corning.

He replied that during the manufacturing process for all shingles, a soapy water is used to cool the shingles and prevent the bundles from sticking together. Sometimes too much is applied and it leaves a heavy residue. Then when it rains for the first time after installation, it foams up and looks like your shingles are being washed. This is nothing the homeowner has to be concerned about as it will not stain surfaces or harm plants, and should only happen the first or second time it rains. (The homeowner said this has happened during every rain for the last 5 months, but it’s been a relatively dry spring so it may just not have rained heavily enough to have washed it all away.) He also informed me that in very rare instances, the copper used in shingles to prevent algae can cause the water to foam.

I called the homeowner back to tell him what I’d learned. He had already contacted GAF who will be sending an inspector out, but he was very surprised and thankful that I’d taken the time to call him back with answers. I told him it was a new question for me so I wanted to know the answer, and wanted to make sure he got the answers he was seeking. He said he appreciated this and wished the people who installed the roof would have told him this.

It felt really good to have an opportunity to provide him with answers after his roofer couldn’t. I did not initially have the answers he needed, but was able to get them within minutes of asking our rep. I work with a knowledgeable, wonderful crew, and our company has formed great relationships with our vendors and manufacturers. I am surrounded by the best team I could ever ask for, which in turn helps me provide better service. It’s things like this that make me love working here.


-Shannon Gassaway, Office Manager