The chimney flashing on my roof leaks and I am looking for a contractor. However, since the chimney passes through a hip in the roof I realize I need someone with experience doing a more complex flashing. What should I look for in terms of materials and techniques?
Thanks!
bit
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Replies
Fold up or pull out the counters, inspect and R&R or not the steps.
If you removed the counters, replace with new copper or lead..a 1/2 wide lip lives in the kerf you just cut in the mortar joint with your diamond blade in a 4.5" grinder.
Roll your PLUGS to secure it in place, caulk with Geocel the kerf closed.
If the steps are OK, I could do it all in about 2 hrs. Depending on the site cond, and slope.
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" out of kindness, i suppose"
Towns, the original.
Materials are probably not as important as technique, and good technique only comes with experience. So look for somebody that's been doing roofs, or chimneys, for lots of years.
Chimney flashing is actually done in two steps. The flashing that is cut into the masonry, which then extends down to meet the rake of the roof on the sides. On the top and bottom sides it bends and extends up/down the roof. The second step is the step flashing. These steps fit under the rake-sides of the other flashing, and extend outward under the tabs of the shingles. Each shingle has a piece of step flash under it, and they are laid so that the water running off of them will end up "Exiting to daylight".
As for the materials, lead, copper, stainless steel, galvanized -- all should be good enough to outlast the roofing materials. And that's the goal -- get the flashing to last longer than the shingles. Then when the shingles go bad, make sure you specify that the roofer should replace any flashing that shows any wear or corrosion.
The process of replacing either one can be done without re-doing the entire roof, but it will involve carefully removing the shingles that meet the chimney. On the other hand, if your shingles are within a few years of their useful life, you might want to plan to do it all now.
Unless you're the lead dog, the view just never changes.
Here is what I see:"
The flashings you have are dreadfully close to the roof. The step flashing should be 3-4" above the sheating break at the least. We canb't see the upper back side of this chimney but if it is only about 1-1/2" above the shingles as it appears it might be, that is the worst of the conditions.
Then - I see that you have architectural type shingles on a house where the chimney and flashings appear much older. There seems to be a spread of plastic roof cement wherre these shingles meet the flashing. That and the previously noted height problem lead me to thnk that this roof was an overlay, and that instead of working the shingles properlyu into the chimney flashing, they just mudded it to the old. ANY failure of that seal could be trapping water instead of shedding it.
Boith of these call for new flashings, cutting the counterflashing into the mortar higher up than these, alnog with some shingle replacement.
Third - I see a contraction avove one flue, possibly a power vent? When modifications like this are added to a chimney, sometimes therre is an increase in condensates within the flue that can find ways of percipitating into the house in ways that appear to be rain leaking. Are you sure the leaks accompany rainfall?
Another problem that can acccompany such reto installations is that a hole is drilled someplace for a power supply to the fan. Since electricians are not roofers, they often choose the worst locations and do the poorest jobs of sealing those holes again.
Closeup photos of the top and back of this stack would help.
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Thanks for all the great feedback.Yes there is an overlay of a second set of shingles.Yes the flashing is as low on the backside as you see in the photos.The vent on the chimney is for a gas insert in one of 2 fireplaces that use a common chimney with 2 flues.The leak happens only under heavy rain (pacific northwest so lots of rain.) When I bought the house I could see out a small hole next to the chimney from inside the attic. I calked as best I could around the flashing.I am not as concerned about price as I am about a good job. Are any of the materials mentioned better than the others?... lead, copper?Thanks again.bitJust because you can doesn't mean you should.
Since the chimney is partially thru the hip not as much water washes down onto it as if it were out in the body of the roof,so it only leaks with heavy rain.
Steps for a permanent cure might be-strip shingles and caps back away saving for relaying.Remove all the old worn out lead from the brickwork.Fabricate and solder the corners of top and bottom copper "pans".Install bottom pan ,,reshingle -step flashing with new copper steps,install top pan and finish shingling.
Now cut out new reglets in the brickwork to accept new lead flashings,at least one course higher than it is now.Re mortar or sealant these reglets and you're set.
Bitman,
on my screen it looks like that chimney is surrounded by dimensional shingles. the adhesive strip on newer dimensional shingles is very aggressive-------so odds are against any removed shingles being re-used----why re-use a damaged shingle?
In your case the wormanship is going to be WAY more important than the type or longevity of the actual materials used. Lead, copper, terne, galv. sheet metal painter with tinners red,pre-painted aluminum----ALL are going to outlast the shingles on that roof if installed correctly. the actual workman is WAY more important.
just ask any candidates exactly how they are going to flash this chimney. AVOID any that don't mention in detail how they are going to cut a reglet to inset the flashing into the masonry----and avoid any who don't mention bending the metal with a sheet metal brake.
Also---it is QUITE possible that any "leak" is NOT comming from the roof/flashing. The position of this particular chimney gaurantees that the flashing doesn't have to handle much water at all.
Only leaks during heavy rains?----how about only heavy rains blowing from a certain direction?-------Take a look at the mortar cap between the flue and the brick work. I don't see one on my screen---and this is a LIKELY location for water infiltration.
Best wishes, Stephen