InspectAPedia®   -   Search InspectApedia

Stone chimney with stone c himney crown (C) Daniel Friedman at InspectApedia.com Stone Chimneys
Stone chimney flashing options to avoid or stop leaks

Stone chimney construction, inspection, flashing details, leak repairs.

This article series describes chimney inspection on the roof, reporting on flashing and leak problems, and inspecting and diagnosing cracks in the sides of a brick chimney.

Above: this stone chimney was flashed with copper during construction, using multiple stepped counter-flashing let into reglets cut into the sides of the stone chimney. This chimney also sports an unusual stone top crown; That flat stone laid over the fireplace flue was placed to stop water entry down the flue when the homeowner abandoned use of her fireplace.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

- Daniel Friedman, Publisher/Editor/Author - See WHO ARE WE?

Stone Chimneys & Stone Chimney Flashing Methods

Stains on chimney exterior, Smallwood NY (C) Daniel FriedmanHere we discuss common problems found at stone or stone-faced chimneys, with particular attention to options offering answers to "what's the best way to install or repair flashing around a stone chimney".

Above: rust stains down a stone chimney in Dutchess County, New York. Notice that the chimney has lots its chimney cap (possibly the original source of those red rust stains), and that the flue extends quite a bit above the stone surround.

On closer inspection the top crown or seal around the flue was mostly missing as well, and water was leaking into the flue, risking frost damage and potentially causing a fire or carbon monoxide hazard at this home.

[Click to enlarge any image]

Details of Flashing a True Stone or River Stone Chimney

Some roofers or masons use the following solutions to avoid leaks around a stone chimney:

Red roof stains traced to chimney (C) InspectApedia

Photo above: rectangular stone chimneys are easy to flash because of their rather straight mortar joints. The red stains below this stone chimney are discussed separately

at CHIMNEY STAINS & LEAKS

Also see CHIMNEY CAP & CROWN DEFINITIONS for more examples of rust damage at chimney tops, caps, and crowns.

Stone cap over a chimney extends past chimney face (C) Daniel Friedman at InspectApedia.com

Also see DISPUTE RESOLUTION on ROOF JOB PROBLEMS

Watch out: for homes built in an earthquake zone, stone chimneys can be particularly hazardous as they were often built without adequate steel reinforcement, as we see in my photo of a collased stone chimney following the Northridge earthquake.

Chimney crushes car (C)  Daniel Friedman

Those details are at EARTHQUAKE DAMAGED CHIMNEYS

Research on Stone Chimney Construction, Flashing, Troubleshooting, Repair

Question: What should I do about ongoing flashing leaks at my stone chimney?

Stone chimney leaks at flashing (C) InspectApedia.com Todd2020/09/23 Todd said:

I purchased a home in Franklin, NC early last year 2019. The person who inspected the home notified us there was a leak around the chimney.

We decided it was best to have the whole metal roof replaced. It has been just over a year now and we still have a leak around my chimney.

The company we hired has been out to my house several times to try to fix the leak and it is still leaking.

They cut into the river rock around my homes chimney to create a metal box. They never replaced the old metal flashing around the chimney when they first came out to install a new metal roof.

I even told the person who first came out to give an estimate there was a leak around the chimney.

So they decided instead of replacing the flashing they would install a metal box around are homes chimney. I feel the metal/tin they're using isn't the proper material to be used sense I have gone online to do some research.

I have read online, that when a roofing company does this they should solder the edges together.

I was told by the roofing company we hired that the metal they are using can't be soldered.

The box they have build is screwed together on each edge and sealed. What should I do?
- Todd

This Q&A were posted originally at ROOF JOB DISPUTE FAQs-2

Moderator reply:

Todd:

Because your chimney is made of hard, rounded river stone it's nearly impossible to actually saw a reglet into the chimney into which the counterflashing can be sealed.

Use of metal flashing around a chimney on a metal roof is perfectly normal and reasonable, though some metals are easier to work-with and form to the chimney than others.

Common leak points at flashing around a stone chimney (C) InspectApedia.com ToddIt's not necessary to solder the edges of roof flashing material and except for working with copper that's not normally attempted. In fact on a metal roof, without special precautions, soldered joints in the metal can lead to flexing as temperatures vary, causing the solder joint to break and fail and leak.

Most critical is the physical arrangement of the flashing, with the counter-flashing properly cut into the chimney at its top, sealed at that location, and properly overlaps at the bottom.

Screwing flashing together might be needed at some locations but of course proper use of sealant between overlapping flashings and sealant around any cuts or screw openings may be important - moreso in some screw opening locations.

It is particularly difficult to flash around stone chimneys because the stones form an irregular surface making mating of the counter-flashing difficult, and because stone is so hard that the usual approach that works well with block or brick chimneys - sawing a kerf into the chimney into which the top of the counter-flashing is inserted - is difficult.

Roofers used to use lead flashing around such irregular surfaces because it could be deformed to better fit the surface. Because we now avoid using lead entirely that's not an option.

Pay close attention to how the counterflashing top edge is sealed against the chimney and look more closely inside, opening the ceiling if necessary, to find exactly where the leak is occurring. Otherwise we're a bit in the dark on this one. On your photo I've indicated some common trouble spots that may leak at flashing around a stone chimney.

 


...

Continue reading at FLASHING, CHIMNEY MISTAKES & LEAKS - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

Suggested citation for this web page

STONE CHIMNEYS, FLASHING, LEAK REPAIR at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to CHIMNEYS & FLUES

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

Questions & answers or comments about chimney flashing leaks & defects that are found by an on-roof inspection.

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification
when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Comment Form is loading comments...

Citations & References

In addition to any citations in the article above, a full list is available on request.



ADVERTISEMENT