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Use EPDM liquid rubber to seal roof gutter leaks:
This article describes using liquid rubber or EPDM liquid rubber to seal leaky on-roof gutter systems such as built-in eaves-trough gutter leaks or on-roof yankee-gutter leaks.
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Reader Question: 5/30/14 Virginia said: how can we repair eaves trough guttering that is leaking into the walls?
We have an old house built in the early 1900's while redoing the walls we found out trough guttering has been leaking into the walls, needless to say before we can continue on with our project we will now need to address the guttering issue I read in an article a person repaired their yankee roofing with a liquid membrane called EPDM Liquid Rubber and butyl tape in areas where needed would this method work to repair metal trough/integral guttering on our home? Thank you
[Click to enlarge any image]
[Originally posted at our contact page.]
Reply: use with caution for a temporary repair
I am not expert on the liquid rubber applied coating solution for leaky gutters, though indeed it has been attempted.
As noted at YANKEE GUTTERS, we have indeed been ab le to make successful temporary patches (good for 1-5 years) in leaky eaves trough & yankee gutter systems using a combination of mesh and flashing cement (GUTTER REPAIR, LEAKY JOINT), and using glue-down EPDM roof flashing tapes as well as glue-down patches using roofing material & flashing cement. An example is shown in our page top photo of a patch going into an aluminum K-style gutter.
However in performing forensic examination of failed metal-lined yankee gutters and eaves trough gutters it became quite apparent that although the flashing cement approach can make a temporary seal, too often the sealant used is actually corrosive to the metal roofing or worse, loosens, traps moisture below the patch, leading to an accelerated failure of the roof or gutter system.
For badly-damaged eaves trough or yankee gutter systems or for systems subject to significant thermal or other movement, I'd worry about any coating's ability to withstand significant thermal movement in the gutter and its parts.
However some EPDM coatings (see list below) are described as usable on metal roofing so may work as well in re-lining a leaky gutter system.
Where are EPDM rubber coatings typically used?
Typically EPDM rubber coatings are recommended for use on weathered metal roofing (Galvanized steel, aluminum, copper), rubber roofing, concrete (little foot traffic), sprayed urethane foam, wood (primed), fiberglass, PVC, acrylic).
Indeed the manufacturers (such as GAF) assert that the coating can stop roof leaks. But the intended use is on a rubber roof not on metal roofing. These coatings and similar ones intended for built-up roofs (BUR) as well as modified bitumen roofs, are applied thin (typically a gallon for 100 ft) - in an approach that's not going to give a thick, resilient, stretch-tolerant gutter liner.
The Yankee gutter I show above, on a home in Poughkeepsie New York, was originally constructed using a galvanized metal lining. Leaks over many years had been repaired using flashing cement, tar, and various stick-on products. Seeking a more durable repair, we decided to remove the old gutter, much of which was rotted, rebuilding the entire system with new treated wood yankee gutter boards and brackets, lining the entire assembly with copper.
Where are EPDM rubber coatings not recommended?
Watch out: if your leaky eaves trough or yankee gutter has already suffered repair attempts using tar, flashing cement, or some other materials, attempting to coat those materials with liquid rubber EPDM products may not work.
EPDM rubber coatings may not work on asphalt roofs without a primer, are not recommended on modified asphalt rool roofing in very cold climates, are not recommended for use on stainless steel surfaces unless the surface is first prepared by sanding, are not used on glass surfaces, will not adhere to silicone or silicone-caulk, are not durable on areas subject to heavy foot traffic.
Steps in Using EPDM rubber to seal a leaky eaves trough gutter or yankee gutter
If the gutter is sound you could give it a try, but as the liquid rubber (some of these products are an acrylic paint) white EPDM roof coatings I've examined are intended for re-coating a roof surface I'm not sure the coating alone will withstand the stresses of expanding and contracting metal in a yankee gutter.
A second class of liquid EPDM coatings are intended for tank linings that, if thicker and if specified for tolerating thermal movement might have a chance.
If you are going to try this approach you'll want to hire a professional, or if it's a DIY project, focus on roof and ladder safety before even thinking about the work itself.
The gutters will need to be completely cleaned and dried, and any gaps, openings, cracks will need to be patched. I use flashing tape or butyl flashing tape or rubber roof repair tape that is rated for use with EPDM figuring that it will be compatible with the coating material.
Finally, the EPDM "rubber" coating is painted uniformly throughout the yankee gutter surface.
Watch out: Understand that it's the patches that you applied over any damage first that will make this repair work at all. Don't count on the coating material to bridge gaps and holes in the gutter.
Watch out: too for leaks at the end drop connection of the downspout to the yankee gutter. This is the most common area to leak on roofs, or one of the first ones. The interior of the end drop downspout connection will probably need to be repaired or replaced where it passes through the house eaves or soffit. otherwise your gutter may not leak (for a time) but its water will still leak into the soffits.
My approach has been to re-line the gutter with modified bitumen, EPDM (rarely), or copper (expensive).
Watch out: finally for new gutter leaks. In my OPINION, no coating-type repair of a gutter is likely to last more than a few years. The Yankee gutters we re-lined in the article above had been patched repeatedly, in fact so many times that it became difficult to maintain the original slope in the gutter bottom.
The layered patches told a story of recurrent leaks and made tracing the exact leak point difficult. Patching and sealing is (in my OPINION) a short term band-aid repair that may make sense particularly if you're trying to stop gutter leaks until time to re-roof the home - a time when it's more economical to do everything that's needed on the roof at one time.
Where to buy EPDM Rubber Coatings
Roof Gutter & Downspout Articles
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