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Topic:   Chimney With Issues - 1384 visits (1 today, 2 this week)

Brian Goodman
Member


Posts: 462
From:Columbus, MS
Registered: Jan 2005

posted December 17, 2005 01:40 PM         

All of these are from one chimney. I've already written up most of what I saw, but I thought this would be a good opportunity to pick the brains of Bob, Dale, et al, for more knowledge. Most of these are about 150kb, trying to keep them big enough to get a good look at without frustrating our friends on dial-up.

A general view above the roof.
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Closer up at one end.
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A good look at the top. The only name I know for the sloped mortar on top is "mortar cap". Is that right, or is there a more correct/accurate term? The big flue is for the main fireplace (wood-burner), the little one goes to the wood heater in the basement.
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A closer look at the small flue.
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One of the "shoulders" where the chimney widens out. Shouldn't there be some sloped mortar here too, to make it drain?
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I found the clean-out under a heavy piece of sheet metal at the chimney base. It had rained all day the day before, and part of that morning.
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And finally, the wood heater in the basement directly below.
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Lots of stuff to talk about. Open Fire!

Bob Harper
Member


Posts: 280
From:Drexel Hill, PA
Registered: May 2005

posted December 17, 2005 05:58 PM            

Too many problems here. Apply for more bandwidth to discuss!

So, you're into trash picking, huh??

This is a nice looking brick pile/ water storage system located on the site of a chimney. They've been having water problems for quite some time. Various mortar repairs, caulked flashing, tar on what's left of the crown wash. Still amazing nobody installed rain caps, made a proper crown wash, or treated with water repellents. Now the thing needs to be torn down to solid material and rebuilt properly. While a lot of damage is from water alone, that mortar obviously had a high lime content to fail so unilaterally. A small wash on the shoulders would help drainage if done properly. Better still, don't build chimneys with offsets in the first place.

I think for the cleanout well they should install some nice stones and plants then stock it with fish.

Old circulator woodstove: pull the chain and flush. No listed liner, cracked flue tile at top (rule out chimney fire), can't see if there's a cleanout within 12-`18" of the stovepipe breeching. While not a lot of combustibles around, would need more pics. Is the top of that single walled stovepipe at least 18" from the joists? Male end down with 3 equidistantly spaced screws per joint? Can't tell what is going on with the discoloration on the pipe in the middle but the elbow looks pretty rusted. Nice soggy walls. That breech is probably full of mud, sludge, creosote, dead animals, and G.O.K.

Looks like a wood fired water heater to me!

I'm out of breath.... Dale, your turn.

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Paul MacLean
Member


Posts: 247
From:Austin, Texas
Registered: Mar 2001

posted December 18, 2005 12:21 PM            

Brian, I'm surprised that chimney is still there after Katrina. Looks like time for a rebuild to me.

------------------
Paul in Austin
www.newdayinspections.com

Brian Goodman
Member


Posts: 462
From:Columbus, MS
Registered: Jan 2005

posted December 18, 2005 07:28 PM         

Now that you mention it, it is a little surprising. We had some pretty rough weather from Kat.

One more. This is from the other chimney on the same house. Bob, should I just recommend monitoring, or further evaluation on this one?

Click for photo (106366 Bytes)

Dan Cullen
Member


Posts: 62
From:Chicago IL
Registered: Dec 2005

posted December 20, 2005 01:29 AM            

Just a reminder to the northerners that a mortar wash doesn't work very well in freezing climates. Limestone, poured concrete, or corrosion resistant metal crown assemblies are highly preferred. Brian, with all the cracks in that second clay tile liner, shouldn't it be replaced with a flex stainless steel liner? Pieces of the clay tile falling in can block the exhaust gases and allow flame or superheated gases to contact combustibles. Were you able to stick your camera in the opening and take a shot down the flue? Did you use an inspection mirror to look up from the cleanout? Small digital cameras can take pretty good shots of areas where our heads can't fit. They can make periscopes of our arms.

Brian Goodman
Member


Posts: 462
From:Columbus, MS
Registered: Jan 2005

posted December 20, 2005 03:16 PM         

Brian, with all the cracks in that second clay tile liner, shouldn't it be replaced with a flex stainless steel liner?

Hi Dan, I'd have to leave that question for someone more thoroughly versed in fireplace technology than myself. Me not know.

Were you able to stick your camera in the opening and take a shot down the flue? Did you use an inspection mirror to look up from the cleanout?

No, this flue has never been used and there were soooo many other issues with the pair of chimneys. I noted and photo'd the obvious, but I referred the whole mess to a chimney professional/specialist, which I'm not. Know thy limitations.

Bob Knauff
Member



Posts: 1302
From:MN
Registered: May 2002

posted December 20, 2005 06:49 PM            

Quite simply and emphatically state in the report: "TEAR DOWN AND REPLACE ENTIRE CHIMNEY IMMEDIATELY TO AVOID POSSIBLE BODILY HARM FROM FALLING BRICKS AND/OR DEATH FROM POSSIBLE CHIMNEY FIRE OR NOXIOUS BY-PRODUCTS OF COMBUSTION LEAKING INTO DWELLING FROM FAILING CHIMNEY STRUCTURE. DO NOT USE FIREPLACE OR WOOD STOVE UNTIL CHIMNEY HAS BEEN REPLACED BY A PROPERLY LICENSED CHIMNEY CONTRACTOR." All of the above text in red and bold. Note: this is not a "recommendation" but rather a statement of fact and adamant warning.

Must be my Old-Timers kicking in again, but I cannot find the thread that recently appeared in this section concerning proper masonry chimney caps and crowns and water shed. Hmmmm...

This image
Proper Chimney Crown Construction (41726 Bytes)

shows a properly constructed concrete crown on a masonry chimney. Around here, the "crown" is the tapered, cement water shed constructed on top of the brick structure and surrounding the flue liners (usualy terra cotta), overhanging the brick face a bit so moisture drops will not be directed against mortar joints or brick below, slightly notched on the underside to guarantee drops will not travel back to the brick face and with a gap created between flue liner tiles and the crown that will be caulked for weather proofing yet remain flexible for flue movement from heating and cooling and not disturb the crown itself. A chimney "cap" is the flat topped metal device, usually with screened sides to keep critters out, that is attached to the top of the chimney flue liner and is designed to keep rain water out of the flue itself. Since the flue acts like a giant rain gauge if left exposed to the sky, water allowed into the flue creates many problems in and of itself.

The contractor who built the chimney in your photo should be barbequed to death over the flue for such a crappy job!

I respectfully disagree with Dan. A mortar crown can be very effective if constructed correctly. A metal crown will tend to direct water towards brick faces much more readily than a properly constructed masonry one plus they lack the esthetics.

For safety reasons, a liner should only be installed in a safe, properly operating chimney flue. Think about it. Should the liner fail, the remaining chimney flue has to be able to handle the flow of hot gases and noxious fumes safely to daylight. If it is not up to the task serious injury may occur.

ANY flat surfaces that would catch or direct water to the chimney structure need to have some sort of taper to them to shed water away. Normally, around here, a bit of cement on top of the bricks at lower, decorative or corbeling levels is tapered at a very strong angle to do the job. Sometimes I see bricks laid at an angle to shed water but this is less desireable since over time, moisture gets between mortar joints of the slanted brick and freezes and deterioration begins.

------------------
Bob

Think Safety!

www.BeaconHomeInspections.com

Proudly serving the Twin Cities and areas surrounding Minneapolis and St. Paul in Minnesota

Bob Harper
Member


Posts: 280
From:Drexel Hill, PA
Registered: May 2005

posted December 21, 2005 04:36 PM            

Bob, I noted several things of interest:

What is a licensed chimney contractor? Do you mean a contractor licensed by the jurisdiction to make home repairs?

Also, you made a statement about liners should only be installed in a chimney that is "safe, properly operating flue". Several questions on that:

Can you define "safe"
can you define "properly operating"?

Also, why are you installing the liner if the above two are met other than sizing?
Where does it say in UL 1777, 441, 641, or 1738 that the chimney must be "safe" and "properly operating" before you reline it? What about after you reline it? Don't you need to re-check it to make sure you didn't make it worse?

Chimneys must be lined per the codes. They give you a choice of materials for use during construction. You can use ASTM C-315 terra cotta flue tiles or you can use firebrick in some instances. If you reline a chimney, it must be with a "listed" liner. The "listing" for chimney liners is UL 1777. The UL listing and the mfrs. instructions call for the chimney to be basically structurally sound. This means a liner is not a recognized repair for a chimney such as the one pictured in this thread that is in dire need of being torn down and rebuilt. What you are calling for is a double liner. Install one liner so the chimney is "safe" and sound before you install the operating liner. This makes no sense. Liners are installed to properly size the stack, contain the heat, smoke, and gases, provide less flow resistance, ease of cleaning, and remain patent (intact) throughout the height of the chimney. When terra cotta fails, you reline it with one liner installed to the listing. When you find an unlined chimney that is othewise structurally sound, you reline it and you're ok. Whether to insulate or not is based on the requirements of the liner and the liner listing. In most cases, heater flues do not have to be insulated. However, 100% of liners for solid fuel are required to be insulated to some degree. How much insulation is determined based upon a Level II inspection.

Liners rarely fail except in cases of misuse, abuse, damage, and chimney fires. If they do, then the annual inspection you should be having would pick up on it and the liner be replaced under warranty as long as you didn't void the warranty by doing things such as burning treated lumber, inducing chimney fires, etc.

I hope this clarifies things.

------------------

Bob Knauff
Member



Posts: 1302
From:MN
Registered: May 2002

posted December 21, 2005 06:30 PM            

Bob H.,

"What is a licensed chimney contractor? Do you mean a contractor licensed by the jurisdiction to make home repairs?"

Around here you are required to be a licensed building contractor to do any building or repairs to buildings for the public. As far as chimneys are concerned a CSIA certified chimney sweep
http://www.csia.org/

who is a building contractor is the best to hire, of course. I could have left the word "chimney" out of the descriptin but yes, a "properly licensed contractor" is required around this area. "Properly licensed" should be generic enough to cover different meanings in other locals.

See this local fellows web site. He is one of the best around here. Note his Minnesota Building Contractors license number (BC-XXXX) in the lower right corner of his home page.
http://www.1stchoicechimney.com/

As an aside here, read the article on Jacks site titled "Tops To Last A Lifetime". Its invaluable and echoes what I have been espousing on this forum for some time concerning chimney crowns.

"Also, you made a statement about liners should only be installed in a chimney that is "safe, properly operating flue"."

This was in response to Dan's question of "...with all the cracks in that second clay tile liner, shouldn't it be replaced with a flex stainless steel liner?"

I attended Dale Febs'seminar on inspecting fireplaces and chimneys recently and the statement of lining safe, working flues only, came directly from him at that time. Since he is recognized as the expert in this field I invite him to comment on it here, if he is not too full of Chrismas cookies and grog yet!

Hope this clarifies things...

Have a Mery Christmas!

------------------
Bob

Think Safety!

www.BeaconHomeInspections.com

Proudly serving the Twin Cities and areas surrounding Minneapolis and St. Paul in Minnesota

Bob Harper
Member


Posts: 280
From:Drexel Hill, PA
Registered: May 2005

posted December 21, 2005 08:00 PM            

I know Jack Pixley quite well since he is the one who passed the torch on to me as Chair of the NCSG Tech Cmte when he got ill. He had asked me to write and article on pouring concrete crowns awhile back. He runs a good operation and believes in training his people.

I was interested to see if you had a local licensing law for sweeps but I see it was the usual "contractor" license, which I agree with to an extent. When we recommend people use contractors with certain credentials, it is incumbent upon the one making the referral to know the qualifications of the referral. If you refer someone to a contractor who causes a mess, in some states, you could he found liable for a "negligent referral". Therefore, referring someone to a contractor who is licensed merely means this guy registered with the city and showed proof of insurance in most cases. As with any professional certification, keep in mind the cert. only proves they passed a course of instruction on that topic--it is not a guarantee. While Dale's program is by far the most complete, it isn't fool proof. I know of graduates who still do things that make you wonder. Dale is responsible for the content of what he teaches but cannot guarantee my actions as a Certified Fireplace Inspector anymore than the CSIA can guarantee the actions of a Certified Chimney Sweep. Sure, its a nice credential but I just don't want to see people build a false sense of security around those who possess this credential as though it is gold. In other words, I'd feel a lot better dealing with a Certified Fp Inspector than a CSIA Certified Chimney Sweep, all things else considered equal.

There are turkeys in every industry and unfortunately many turkeys have the ability to pass certifications yet still manage to make goofy decisions. I know I made a mistake once! ;-)

I'll wait and let Dale speak to the liner inside a "safe" chimney question.

I don't know if those Californian's know what the hell grog is but I'm sure he found some eggnogg.

------------------

Dan Cullen
Member


Posts: 62
From:Chicago IL
Registered: Dec 2005

posted December 21, 2005 08:37 PM            

Hi Bob K. Thanks for the information. Could you tell us what exactly is a properly constructed mortar crown? And perhaps you could explain why most of the mortar wash crowns that I see are cracked, loose, and allowing moisture to saturate the brick masonry below? A well constructed galvanized crown with a nice little kick at the lower edge acts just like an anodized aluminum coping or an overhanging drip edge that helps keep the runoff from saturating the brick face below. Mortar is a weak material unless it's sandwiched between masonry units or spread over stainless expanded lath.

Brian Goodman
Member


Posts: 462
From:Columbus, MS
Registered: Jan 2005

posted December 21, 2005 10:59 PM         

For what it's worth, I see a lot of variation in mortar crowns down here in sunny/humid as hell Mississippi. I see 'em two years old with big cracks and 15 years old with none at all. I've always thought it had to be due to the specifics of the mix and/or conditions at installation.

Bob Knauff
Member



Posts: 1302
From:MN
Registered: May 2002

posted December 22, 2005 03:19 PM            

Dan,

"Could you tell us what exactly is a properly constructed mortar crown?"

Rather than try to type all that information again about a properly constructed chimney crown, please go to Mr. Pixleys website:
http://www.1stchoicechimney.com/

Click on "Tops To Last a Lifetime", fill out his little form and download the outstanding brochure he offers there for free. Save that brochure, it will be a valuable reference.

"...perhaps you could explain why most of the mortar wash crowns that I see are cracked, loose, and allowing moisture to saturate the brick masonry below?"

That's an easy one as you will discover after you read Mr. Pixleys explaination. I recently saw a series of images of a terra cotta flue liner that had a hairline crack traveling vertically up one corner, top to bottom. The next photo showed that same flues hairline crack after a goodly amount of heat had been applied to it as a test. The terra cotta had expanded so much from heat that the crack was now nearly 1/4" wide open the entire height of the piece!! After coolinga and shrinking, the crack was again just a hairline. Very impressive demo.

99.99999999% of the concrete crowns I see around here have been installed so as to be in direct contact with the terra cotta flue liner, the installer thinking that made the crown water tight, I'm sure. It did, until the flue liner (and ones below it) heated. Heat causes that tpe of liner to expand in all directions. Multiply the vertical expansion by the number of terra cotta tiles in the stack and the pile can move up and down a LOT. Factor in the horizontal expansion of the tile in direct contact with the concrete crown and what chance does the poor crown have of NOT being shifted and/or cracked. It is bound to be, sooner or later but usually sooner. Once the crown is cracked, we have to deal with the freeze thaw problem also up here in the Great White North. Is it any wonder we see so many damaged crowns?

The other common error in crown construction is terminating the edge of the crown at the brick face of the structure. All water shed is then directed right down the face of the bricks and mortar below. Soon deterioration in the form of spalling, loose bricks, loose mortar and so on begins.

Brians' statement is interesting, "I see 'em two years old with big cracks and 15 years old with none at all. I've always thought it had to be due to the specifics of the mix and/or conditions at installation." and Dan, you said, "Mortar is a weak material unless it's sandwiched between masonry units or spread over stainless expanded lath."

As we've seen, all that crown damage is a design/build problem. That simple. A concrete chimney crown carries no structural weight (per se) but is mostly there to shed water. Even less than the best batch of concrete mix should stand up pretty well for a long long time provided the crown is constructed properly.

You are correct Dan, "A well constructed galvanized crown with a nice little kick at the lower edge acts just like an anodized aluminum coping or an overhanging drip edge that helps keep the runoff from saturating the brick face below." However, there IS still the issue of water sealing the gap between metal crown and flue tiles.

Besides, as I said before, I guess I am a purist and believe in continuity of architectural details on a house. A metal crown on a brick chimney, when not designed that way, is akin to placing real butcher block counter top material right next to Formica butcher block counter top material. The difference is so striking that the real wood looks bad AND the Formica looks bad, IMHO.

Check out the pics I have under this section of the forum at the Lightening Strike thread, if you haven't already. If that damage to the flues and crown hadn't been due to lightening it most certainly was due to flue movement when heated from the fireplace use, plus the subsequent freeze thaw cycles. That type of crown cracking is so common I'd bet Bob Harpers annual salary I'd find that exact same condition on any given masonry chimney structure I was asked to inspect in any season and any area of town. You know how THAT goes Dan.

Bob H., I couldn't agree with you more about licensing and "turkeys" in any trade. No specific license required for fireplace/chimney contractors that I know of, just the BC license around here. I use the generic language as stated above in my report but give the clients a list of a few contractors who I feel are qualified, beginning with Jacks company, and stress the need to make sure the contractor is BC licensed AND a member of CSIA. Jack has it pretty good though, he is normally so busy he will not travel very far from the northern "burbs" for a job. Doesn't have to! Ha!

Mmmmmmm......rum and eggnog......See Ya!

------------------
Bob

Think Safety!

www.BeaconHomeInspections.com

Proudly serving the Twin Cities and areas surrounding Minneapolis and St. Paul in Minnesota

Dan Cullen
Member


Posts: 62
From:Chicago IL
Registered: Dec 2005

posted December 22, 2005 05:59 PM            

Hi Bob...thanks for the extremely informative post. It all makes sense. Here in Chicago the galvanized crowns make up the bulk of the installs on the predominant architectural style we call, 'The Irish 3 Flat'. so they don't stand out like a sore thumb anymore. A nicely detailed, corbelled, and limestone capped chimney is a thing of beauty but they are quite rare on new work until you get out to the ritzy North Shore. My girlfriend just purchased a converted loft in 'The Cities' and I wish I had had you inspect it. Thanks again.

Dan Cullen
Member


Posts: 62
From:Chicago IL
Registered: Dec 2005

posted December 22, 2005 06:11 PM            

I just read Jack Pixley's article and thoroughly enjoyed doing so. I see from whence some of our misunderstanding has arisen. When I use the term 'mortar wash' I am referring to a sloped application of mortar such as 'Brixment' with no reinforcing, no form, and no aggregate. This is the system which I see frequently and which is almost always cracked and loose and allowing moisture to penetrate the masonry. What Mr. Pixley installs is a 'poured concrete chimney crown' a totally different animal and a great way to protect a masonry chimney.

Bob Knauff
Member



Posts: 1302
From:MN
Registered: May 2002

posted December 22, 2005 07:29 PM            

Dan,

What is 'Brixment'? Have a website for the stuff?

If you get to The Cities to visit the girl friend look me up, I'll buy you a cup of coffee!

------------------
Bob

Think Safety!

www.BeaconHomeInspections.com

Proudly serving the Twin Cities and areas surrounding Minneapolis and St. Paul in Minnesota

[This message has been edited by Bob Knauff (edited December 22, 2005).]

Bob Harper
Member


Posts: 280
From:Drexel Hill, PA
Registered: May 2005

posted December 22, 2005 08:21 PM            

Brixment is simply their local brand of cement products.

There have been various forms on the market for over 15 yrs. to facilitate pouring concrete crowns. There are various cementitious products to use in pouring,coating, rebuilding, and repairing crowns.

Regular mortars will shrink when laid more than about 1/2" thick. You can use mortar in thicker applications such as patching holes in walls but you need to pre-hydrate the mortar first and use fiber reinforcing. You also need to really soak everything so it doesn't suck all the moisture out of the mortar which causes shrinking and cracks.

High lime mortars such as type 'O' can exhibit autogenous healing. This is simply recarbonation of the lime with CO2 from the air. Even if you coat mortars with an elastic material, you still could suffer the physical shifts described by Bob K. A lot of sweeps install a bond break of sheetmetal just under the crown to prevent the upheaval which can look that the first photo here. This is why the liner should float independently of the chimney proper. As Bob K. pointed out, there is thermal expansion both laterally and longitudinally.

When I pour crowns, I make a special concrete with air entrainment (type 1A) and glass fiber reinforcement. The air entrainment creates micro pockets within the concrete that act as shock absorbers which minimizes the forces from freeze-thaw cycles. The glass fibers not only hold it together the same way hog hair was used in plaster and stucco, but it eliminates "surface bleed". When you pour concrete, the little bubbles rise leaving thousands of micro chimneys that can introduce water, salt, etc. deep into the concrete matrix. The fibers act as magnets collecting the bubbles so they don't rise to form chimneys. Instead, they act as micro shock absorbers much as with air entrainment.

Mortar crowns are simply concrete with the aggregate missing. You know how strong that is....

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Phillip Stojanik
Member


Posts: 887
From:Houston, Texas
Registered: Aug 2002

posted December 22, 2005 09:58 PM            

Wow!

That first pic at the top of this thread really tells a story about how not to design an exposed masonry chimney structure if you want it to last. It may have taken a while to come to pass, but it’s the design of the brickwork that sealed the fate of that chimney structure from the day it was built.

That particular design does not shed water effectively at all and the wear pattern on the vulnerable mortar joints really illustrates that point. The drip/drainage plane has to be moved beyond the bulk of the vertical structure as close to the top as possible! They did not do that here nor did they provide sufficient slope to the topmost horizontal surface.

Bad design from the get-go means poor performance over time!

Dan Cullen
Member


Posts: 62
From:Chicago IL
Registered: Dec 2005

posted December 22, 2005 09:59 PM            

Bob K. I will drop you a line my next time up MN way.

Bob H. Would it make sense to apply a silane based mortar sealer to the concrete crown? Would the crete have to dry a month or so first?

Bob Harper
Member


Posts: 280
From:Drexel Hill, PA
Registered: May 2005

posted December 23, 2005 02:41 PM            

Technically, all masonry should cure for the full 28 day full compressive strength. In reality, if the rest of the chimney has cured and is dry, that time can certainly be shortened but your guess is as good as mine on how much.

Silanes work by plugging the pores with solids and therefore, are not 100% vapor permeable. You wouldn't want to wrap that chimney in plastic would you? All masonry should breathe. Having said that, there is a surge with sweeps applying acrylic based sealers to crowns. The theory is, the crown flexes but seals while the rest of the chimney breathes. Time will tell if it works.

Go to www.saversystems.com for a lot more info. and some great products.

HTH,
Bob H.

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Dan Cullen
Member


Posts: 62
From:Chicago IL
Registered: Dec 2005

posted December 25, 2005 12:33 PM            

Bob H. I thought silane based masonry sealants were sold largley on their ability to prevent penetration of liquid water through the masonry exterior while allowing moisture vapor to escape from the inside out. If you're concerned with moisture entering the pores of the poured concrete crown it seems like a few rope weeps at the base of the crown might be in order as well as a silane application. Can't point to any technical data to back me up...just kinda off the cuff thoughts on the matter. BTW, concrete achieves 90% of it's strength in 28 days. But I'm sure that varies with mix, weather, etc.

Bob Harper
Member


Posts: 280
From:Drexel Hill, PA
Registered: May 2005

posted December 27, 2005 07:07 PM            

Hi Dan. Yes, the Hoover Dam is still curing so it hasn't technically reached 'full' compressive strength yet. However, 28 days is the generally accepted rule for most masonry and concrete. Yes, the mix, weather, pour conditions, etc. all effect the cure. They have cooling water piped through the Hoover Dam to control the massive heat from the exothermic reaction of hydration.

Maybe you're right but the last I saw was that silanes blocked the pores with solids. The Chimney Saver product I referred you to is a modified polysiloxane. It works by changing the electrostatic charge of the surface to the same polarity as water and thus repel. This gives it excellent gap filling properties while breathing 100%.
Yes, some sort of drip edge needs to be formed in the overhang. While placing rope in the forms works, it tends to move and leaves an irregular channel. Most newer forms have the drip edge molded into them. Using older flat forms, I used to cut the groove with a mini grinder and diamond blade.

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Dale W. Feb
Member


Posts: 99
From:Thousand Oaks, Ca.
Registered: Jan 2001

posted December 28, 2005 09:44 PM            

In response to the question regarding our class information. The chimney structure, (the brickwork) must be structurally sound (not to say that I am a structural engineer) in order for the liner system to be properly applied. If the structure is damaged, it must be repaired or replaced prior to the installation of the liner system. All listed liner system hold this requirements based on the UL 1777 standard. The liner is not considered a structural element of the system.

There are questions regarding the mortar crown, wash or cap (whatever you wish to call it in your region). If you create a drip edge, will this help? I would say yes under perfect conditions with no wind. Unfortunately, very few storms arrive without wind-driven rain. The key to a good crown is the application and finish. Most installers fail to wet the brickwork prior to application. This pulls the moisture out of the mortar/concrete and results in shrink cracks and lifting of the edges. If you have not noticed, the quality of masonry construction has greatly deteriorated. Take a close look at some of the brick building built in the 1600s. If you notice, most of the mortar joints are tooled or compressed with a finish tool. This tool runs the mortar joint as pressure is applied. This compresses the mortar and brings the moisture to the surface. It is this action that provides the best protection and long life of this product. In my area, I don’t believe that anyone tools the bed or head joints at all. I’m not sure if they even own the tool. This same application can apply to the mortar crown or wash. This smooth surface created by compression leaves a long lasting surface if properly applied with proper materials.

The chimney in the picture shows fairly even expansion outward away from the heater flue. This to me indicates freeze and thaw, rapid expansion of the flue liner, or a lightning strike. Since this is a heater flue, it is not likely that there was any form of chimney fire. What is clear is the large amount of moisture entry traveling down around the outside of the flue liner for the heater. This is supported by the patterns behind the heater. It appears that moisture is traveling between the clay flue liner and the exterior brick structure. Is this chimney in an area that is susceptible to freezing?

This could have also been a lightning strike. Bob had talked about not standing in front of the fireplace during a lightning storm (due to potential physical injury). The reason for this is because lightning goes in and must exit. Where it exits is the big question. Is it at the base close to grounding or does it blow out the brickwork at the top? Each event will be slightly different. Even if I had dry-stacked these bricks without mortar, they would not move out away from the liner without a driving force. Just tired thoughts from a cold ridden victim. I’ll add more when my head is clear.

I hope you all had a great holiday and wish you a happy New Year.

Dale W. Feb,
Executive Director
Fireplace Investigation, Research & Education Service
Moorpark California & Richmond Virginia
Ph. (805) 552-9958 Fax (805) 552-9123
“Preparing For The Future” www.fireservice@earthlink.net www.F-I-R-E-Service.com www.FIREexchange.info

[This message has been edited by Dale W. Feb (edited January 05, 2006).]