Floating deck membrane leak

Old 11-01-04, 08:06 PM
Tom S.
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Angry Floating deck membrane leak

Our house is about 20 years old and we have been in it about 11 years. There is a small balcony (8' x 9') accessed through sliding doors from one of the 2nd floor bedrooms. The balcony is cut into the roofline and walled in on one side by the house (sliding doors), on one side by a wall on the back of the garage, and on two sides by 3' walls that intersect the roofline. The balcony is over the top of part of the garage. There was a floating deck layer (1" x 6" redwood boards) attached to 2" x 2" sleepers laying directly on top of some kind of membrane. The membrane acts like a swimming pool liner and goes up behind the vertical cedar siding on all sides. There is a cutout that drains into a downspout that penetrates into the ceiling of the garage and then exits through the side of the garage.

The membrane leaks and allows water to drain over the top of the drywall ceiling of the garage and then down into the garage. I removed all the decking, cleaned off all the debris and carefully washed down the membrane. It looks like a previous owner put some nail holes in the membrane and one of the seems has a small opening.

I'm trying to figure out if and how to patch the membrane and having been doing some internet research. I've been reading about EPDM membranes. Do any of you know how I can tell what type of membrane it is-it was installed as part of original house around 1983. I've read about some liquid repairs like Liquid Rubber and Liquid Roof that may work but would like to make sure before I buy or apply them. Plus I'm concerned about possibly damaging the membrane if I pick the wrong kind of repair/patching material.

I'm hoping that I don't have to replace the complete liner because that would involve removing all the vertical cedar siding and I'm not sure how easy it would be to get matching siding and match the stain.

Any help would be greatly appreciated.

Tom S.
Old 11-04-04, 01:39 PM
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If it is EPDM, it is just like we used to patch our bike innertubes, except you dont need the cement anymore. The adhesive is pre-applied.

Go to a roofing supplier (not "Home Depot") in your area and get a small roll of self adhering EPDM flashing membrane 8" wide or so.
Clean the area real good that you want to patch with unleaded gas on a rag. you want to get back down to the virgin black rubber.
Then cut the flashing into a peice that is 3" bigger on all sides than whatever you are trying to cover and round off the corners of the patch. 1 nail hole = a 6" square patch.
Remove the release paper and stick it down and roll it real good with a small hand roller. (they sell those too)...done.

peice of cake

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