Chimney Operation Satisfaction

Rain entering the chimney

Exhausting high efficiency gas can erode liners

What is the most active part of your home yet never moves, it’s the chimney, 24/7/365 thousands of cubic feet of air travel through it, some clean some not so clean. No homeowner should assume their chimney can be used without a thorough examination, both exterior and interior. Rain, flue gases, and freezing moisture cause erosion and deterioration to chimneys. Breaks in the chimney liner even small ones-can reduce the chimneys ability to vent all the products of combustion gases and condensation to enter the home structure.


While viewing the Chim-Scan screen from the heart or chimney base, homeowners can view the condition on their fireplace and/or chimney. The Scan operator can point out vital information about the chimneys interior condition. In gas and oil central heating systems early detection of condensates within the chimney can help prevent additional costly home repairs. As indicated in the photo below the condensates from high efficiency units can literally eat way the chimney liner casing. The liner chips falls and can possibly close off the connector pipe!

In the past, the examination of the chimney interior involved either an ineffective flashlight and mirror or the expensive disassembly of part of the the chimney to see problem areas. Now with the Chim-Scan video inspection service, it is easy to obtain an accurate evaluation of your chimney’s interior in a non-destructive way. Your chimney professional will be able to show you these precarious conditions, if they exist:

*Improper new construction

*Chimney fire damage

*Improper prefabricated chimney connection

*Deterioration from gas appliance connections

*Cracks, even hairline cracks, in flue liners

*Broken or mission tile liners and mortal joints

*Deterioration of the smoke shelf or damper

*”Quick-Fixed” thimble holes

* Hidden Breaches

*Nest, limbs and other blockages

75% of mortar has been eroded away due to weather
Open Mortar joint – Exhausting combustibles into wrong area outside the chimney

Pyrolized creosote and cracked flue liner

Increased use of fireplaces and wood heat has resulted in an increase in chimney fires. When conducting a sudden occurrence in investigation, a Chim-Scan video inspection service can give you the reliable information you need. An examination soon after the mishap can determine the cause of damage. Whitened mortar joints, blaze marks, missing mortar, cracks and discoloration in liners and buckling of steel liners are indications of sudden occurrence chimney damage.

Your inspection may provide several reports formats: a written report on a chimney evaluation form or digital photographs and reports which can be emailed.

A video inspection of a chimney interior offers both the Fire Investigator and the Insurance Adjustor these important benefits:

* You get detailed information, obtained by only inches away from the chimney walls.

* You get complete documentation in a variety of digital formats.

* You save time on claim processing by getting reliable information easily. If requested, an estimate for repair may be offered by the inspecting company


Vertical Crack in Corner of tile

Unlocked/disengaged Prefabricated chimney Liner

Exhausting high efficiency gas can erode liners

Accurate information is important is important for making decisions about a chimney. National Fire Protection Agency (NFPA) 211 codes – 2013 edition requires companies to do a Level II inspections when a home is sold or new heating appliances are being installed. Chim-Scan equipment allows the operator to do Level II inspections and document the findings. If you are a homeowner having your chimney swept, ask for a video inspection. Seeing the interior of your chimney will give you added peace of mind and a general knowledge of your chimney system. So ask for it by name, “I want a Chim-Scan done on my chimney!”

If you are a fire inspector or insurance adjustor, your evaluations should be based on accurate and documentable information. Take the guesswork out of a chimney evaluation by hiring a chimney professional who has Chim-Scan video evaluation system.

Is that open space between liners that big a deal?

Unlocked/disengaged Prefabricated chimney Liner

Ok why do I need to know about open spaces in my chimney? All I want to know, is the chimney is safe to use.

Well that’s a valid question to ask, but it does require a little understanding of what your chimney does. Remember smoke, heated gases and some sparks use the chimney for a passageway from your fireplace or appliance to the great outdoors. Having gaps in between the liners could put yourself or your home in harms way by letting these things escape!

Think again.

Let’s look at this closely. If you have a chimney liner that has 7”x7” interior dimensions and a 1/16th inch gap between the next liner, the open area equals 3 sq. inches. Place 9 more liners on top of this, with the same 1/16th of an inch opening, collectively you have 30.38 sq. inches. This is larger than a 6” hole. So that “not so bad mortar joint”, may not be serving you or your chimney very well.

In another example, let’s ramp it up a little by taking a 13”x13” liner, which is common for a fireplace chimney. Consider a one inch gap between the liners, which is not uncommon. We have 52 sq. Inch open area in one liner joint area. That’s larger than an 8” hole. Add 4 more liners to the top of this one and you have a whopping 260” sq. Inch opening, larger than a 18” round hole.

Get the idea?

Chimneys operate under a negative pressure or vacuum, so how can we expect the chimney or fireplace to operate with gaps? If this was your vacuum cleaner you would notice if it wasn’t working well.

Consider this example chimney in newer home construction or renovation of an older home. This could become a real problem in performance and energy efficiency. Tighter homes compete for air so who is going to lose the battle for make up air? Your Chimney! Even though there may be a brick or block to surround the liners, it will still leak air into the chimney. This can contribute to the summertime damp/smoky odor you may experience from time to time.

Also remember when smoke and hot gases cool, they condense on the walls of the liners and roll down to the gap and can enter into the interior chimney cavity. (Not good!)


Something to keep in mind

There are national recommendations from the building codes concerning this issue. Even though the codes do explain in detail how clay liners are to be joined, (NFPA 211 or IRC) both code bodies understand that the smallest hole can create a loss in performance when trying to exhaust smoke and gases from a fireplace or appliance. Gaps can create uncertainty, on how the fireplace or appliance will operate under all conditions. Smoke and gases can move into other areas within the chimney cavity creating more uncertainty.

Uncertainty is not your friend.

Remember you have a variety of solutions to stop the leaking, whether a chimney reline, resurface or joint repair. If you were wondering if gaps are a big deal, yes they are!

What the sweep is telling you!

*Your chimney falls below recommended building codes.

*Even though the chimney may appear to operate, it is doing so in a limited availability. And the condition will only prematurely deteriorate the chimney at an accelerated rate.

*If you’re asking “is it safe to use,” I can not offer you any peace of mind in its current condition.

Todays technology and higher demands for efficiency and performance are now ramped up higher than before. So yesterdays though process will not work with todays reality.

Here’s a demonstration to easily explain this problem.

* Take a beverage straw and make a small hole in it.

* Place a draw into beverage and draw on it.

* Once the beverage drops below the hole, there should be a sound coming from the straw plus you’ll work twice as hard to draw the beverage through the straw.

* This simple concept is the same with the chimney.

Now, do you understand why there’s smoke standing on the front of your fireplace?