Drip, drip, drip - not a quick, easy fix

House Doctor | Gary Dymski

June 1, 2006

FlexWrap flashing tape from Tyvek, a DuPont company, helped fix the pesky leak in Gary Dymski's garage ceiling. (June 1, 2006)

My wife has impeccable timing. There I was, enjoying a near-perfect Saturday night. It was mid-winter, with about 5 inches of fresh white stuff blanketing the ground. I was burrowed into the recliner, with logs snap-crackle-popping in the fireplace and a hockey game on the tube.

Returning from a search of our spare refrigerator in the garage, my wife had two bolts of bad news. "What do you want first?" she queried. "The bad or the real bad?"

"Give me the bad."

"You're out of Molson Canadian," she said.

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Watching "Hockey Night in Canada" without an ice-cold beer is like Thanksgiving without turkey. "So what could be worse?" I said, providing her an opening for the second bolt.

"You have a leak. Water is leaking from the ceiling in the garage."

Of all the do-it-yourself repairs in all the homes I've owned, nothing is more frightening than water leaking from the roof. Especially in winter.

That night, I put a bucket under the leak. I also made a quick visual inspection of the rooms above the garage, a bedroom and an adjoining bathroom. From the wet spot on the garage ceiling, it was all but obvious the leak was from the roof overhang. But I wanted to be sure there wasn't a plumbing problem upstairs. With no leaks under the vanity in the bathroom and no damp spots on the carpet in the bedroom, my initial analysis appeared sound.

That was almost six months ago. Not until a recent weekend was I finally able to find and stop that leak. One reason it took so long was the leak's location. Cutting away wet drywall on the garage ceiling exposed wood framing and sheathing. I could clearly see water was not seeping into flooring, insulation, interior walls and carpeting, so there was virtually no chance for mold or moisture damage. During rain and snow, water would simply drip, drip, drip to the garage floor. Without a sense of urgency, I could afford to wait. Plus, who wants to climb on a roof in winter?

Well, with winter long over, the leak was driving me nuts. I picked a sunny Sunday morning to tackle the repair.

Several months of watching the leak helped me determine that it probably was originating from one of two areas: the metal flashing where the roof overhang meets the exterior siding or the sheathing behind my vinyl siding. There was a small chance the leak could be coming from the bedroom window, but I doubted it. Windows have weep holes that allow water to drain from the sill and outside track. After I cleaned the sill one spring day, the weep holes allowed water to drain freely. And there was no water dripping from that hole in the ceiling.

The only way to find the leak was to remove the siding and the rigid foam board beneath the window. Removing the siding also would expose the flashing.

Once I climbed the ladder to the overhang, I needed only a few items - a vinyl-siding removal tool, a hammer and a pry bar - to pull off the siding and foam insulation board. The siding tool disconnects two pieces of siding with little effort. The tool's curved point slips between the two pieces at one end, and as it slides along the joint, the pieces separate. Vinyl panels are held loosely in place on the exterior wood sheathing by flat-head roofing nails. I used the pry bar and hammer to pull out the nails.

With the siding - about four or five panels - and foam board removed, I quickly was down to the Tyvek, or the weather-resistant barrier that covers the wood sheathing. A kind of housewrap, Tyvek helps keep water and air from penetrating the siding. The barrier acts as a windbreaker; it's not waterproof, but it helps insulate the house.

Both the Tyvek and the flashing, located at the bottom of the wall where it meets the roofline, appeared sound. The Tyvek was free of holes or rips, and the flashing covered the seam between the wall and the roof edge. To be sure, however, I slowly poured a couple of buckets of water along the flashing. The ceiling, which, remember, had been exposed from the inside of the garage, showed no moisture.

Just to be sure, we tested the window again. While my wife slowly poured water along the sill and the outside track, I waited in the garage below. I could hear the water washing over the shingles and into the gutter. However, none of it dripped through the exposed hole in the ceiling.

There could be only one other explanation. Using a utility knife, I cut vertically into the Tyvek, which is paper thin. I made my cuts along the wall, almost exactly above the exposed hole in the garage ceiling. Peeling away the Tyvek, I found the source of my trouble. Two pieces of wood sheathing were now exposed, and between them was about a 1/8-inch gap. I reached into the open window and grabbed a wet sponge from the bucket. My wife was waiting in the garage, and, seconds after squeezing water from the sponge into the gap, we identified the leak. "That's it," my wife called out.

The gap was letting water from wind-swept rains or melting snow into the garage. Sealing the gap would be easy. I had some Tyvek tape (about $12 a roll at home centers or building supply stores), along with a few strips of Tyvek FlexWrap, a tape-like, moldable flashing that is designed to seal such gaps. I had picked up the FlexWrap samples at a recent trade show, figuring it might come in handy for this project. Cutting the Tyvek from the base of the window to the bottom of the flashing, I exposed the length of the gap in the sheathing. I covered it with FlexWrap, then put the Tyvek back into place and sealed its vertical cuts with the Tyvek tape. I also used a few small dabs of black roof caulk to seal crimps in the flashing where it attached to the sheathing.

Once everything was sealed, I reattached the foam board and siding. I then tested the repair by shooting streams of water from a garden hose across the windows and the siding. As water ran down the overhang, I watched from the driveway to see if anything dripped from the hole in the garage ceiling. Success. Dry as the desert.

It had been a long, hot day on the roof. I had started in the late morning, and now it was nearly 6 p.m. Even with daytime temperatures only in the mid 70s, the sun had heated the shingles so I couldn't lay on them. I spread out an old furniture pad to keep from being toasted on the roof. As I wound up the hose, I exhaled deeply. My wife emerged from the garage with her hands behind her back.

"Here." It was a cold bottle of Molson. "You know, there's a playoff game on tonight," she said. "It starts in about an hour."