Chimney Leak in Oconomowoc, WI Requires A Long Term Fix
After trying the standard contractor ‘fix’ (which is to apply caulk or tar), this Oconomowoc, WI homeowner sought out a permanent fix. GSB Services, LLC was contacted to provide an estimate. We thoroughly explained how chimneys and roofs work together, how to properly flash them, and the importance of waterproofing large stone chimneys. On this chimney, we proposed removing the existing galvanized steel one piece flashing from the chimney and the surrounding shingles and properly installing a new two-part chimney flashing using prefinished steel.
We removed the old rusted steel flashing which had been leaking into the living room area of the house and staining the beautiful lannon stone fireplace. After removing the surrounding shingles we installed an ice and water shield underlayment on the roof and extending up the sides of the chimney. This is an important step. Without the waterproofing membrane up the sides of the chimney, ice damming and wind driven rain can allow water to seep in. It is also important to have a level of craftsman ship here. The corners need to be cut and folded precisely to create a water tight barrier in the underlayment.
Next we installed the front piece of base metal called a wall apron or apron flashing. This metal was fabricated out of prefinished steel in a medium bronze color to match the weatherwood shingles.
Following the apron flashing, we installed the step tin shingles. These are fabricated from the same prefinished steel material. The function is to tie into the roofing shingles and extend up the side of the chimney. The shingles are interlaced with each course of step tins used. The last course is tied in with the saddle flashing at the back of the chimney before the roofing continues. It is important that each course of shingle have its own step tin flashing for a proper installation.
The last part of the base flashing is the saddle or cricket flashing. Large chimneys need to be able to divert the water that builds up behind them to the sides. This is part of the building codes. The cricket or saddle provides a raised area in the center to accomplish this. The prefinished steel flashing is then fabricated to fit with this raised center and divert the water to the corners. Notice again how the step tin flashing is tied into the saddle flashing. We also installed another layer of ice and water shield underlayment at this time. The rest of the shingles were then installed.
After the base flashing was installed, it was time to install the counter flashing. Counter flashing is the part of the flashing system that is attached to the chimney and flashes over the top of the base flashing forming a water shedding surface. It is important that there are two parts to the flashing system to allow for expansion and contraction and the natural settling that houses experience. This required our cutting into the mortar joints with a diamond bladed saw. This allows us to form the counter flashing panel with a lip that locks into the mortar joint. The side pieces were formed out of individual panels.
Finishing off the flashing with a high quality terpolymer sealant insures that this chimney will last for years. We got pretty close on the shingle match, too, even though the roof was 5-7 years old. We also recommended cleaning the lannon stone, waterproofing the chimney with a clear sealer that seals the chimney from moisture soaking into it, and coating the top crown with a crown coat (a further waterproofing measure). The customer will do that work in the future. We did this repair in 2009 and it has remained leak free.
Do you want help with your hard to solve chimney leak? Tired of contractors offering to tar it or put more caulk up there? We have the real solutions that will last the life of your chimney. Please feel free to get in touch with us.