One of the top sources for roof leaks is the flashing around the chimney. Making and installing flashings on the roof is part art and science and it takes a considerable amount of skill to do properly; I’ve found that the art end of the job is what gets people in trouble. The following pictures show how we do our work; the flashings we make for chimneys and skylights are bulletproof and have never caused us to return to a clients house again, I also think they are lovely to look at.
We measure the length and width of your chimney and the slope of your roof. The flashings are custom made in our sheet metal shop for your chimney. Depending on the type of roof we can make the flashings from zinc, copper, stainless steel, aluminum and lead coated copper; they can also be painted any color you wish. We can fabricate flashings of any size no matter how big or small your chimney or skylight.
Once the flashings are made they are sent out to the project with all other necessary materials. The pictures below show the old flashing and shingles being removed, some rotted wood being replaced and finally the installation of waterproof underlayment.
The old flashing is rusted through tin
new piece of 1x6 roof decking where the other had rotted
Installing waterproof underlayment around the chimney
Most elements on a slate or shingle roof are installed from the bottom up, here we start by installing the lowest flashing called the apron.
Installing the copper apron flashing
Next we install step flashings, step flashing are small “L” shaped pieces of metal that are laced in to each course of shingles as they climb up the side of the chimney.
Step flashings are installed in each course of shingles
This is the most critical piece of the entire assembly, the pan flashing does most of the work in shedding water. We form our pan flashings with a rounded bottom edge (vs. a sharp fold) to keep this area dry; creased or square folded metal can hold water which leads to corrosion and leakage. All of the seams we use are double locked and are completely waterproof, no matter what nature throws at this house the chimney will not leak.
Copper pan flashing being installed behind the chimney
The pieces that cover the step flashing along the sides of the chimney are called counter-flashings, here it is being trimmed to fit beneath the pan and over the apron flashing.
Counter flashing being installed on the chimney sides
The final step is applying a bead of high quality sealant to the joint between the new flashings and the masonry.
Completed copper chimney flashing repair
This roof will be good for another five years, when replacement of the roof becomes necessary our flashings can be reused. If your chimney or skylight is leaking we have a bulletproof solution, call any time and we will be on our way.
Tom 703-299-8888
P.S. If you are out our of our service area we can make and ship a complete skylight or chimney flashing kit to you. All you need to tell us is the measurements of the chimney or skylight and the slope of your roof and we can have it on the way to you in a day or two. Just call 703-299-8888
