FAQ

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Improper chimney sizing is primarily an issue when venting appliances. A very common example of this is the fireplace insert or woodstove which is vented without a proper liner into the smoke chamber of a typical fireplace. This is a real problem. This type of installation is commonly referred to as a slammer.

Slammers are notorious for creating dangerous messes of creosote which can ignite into a chimney fire. Chimney fires are very dangerous things. In addition to pass through heat which can ignite the combustibles surrounding or adjacent to a masonry chimney, burning debris can exit the chimney and ignite a home from the roof down.

The way to eliminate the problems created by a slammer type installation is to properly vent all appliances with a liner sized to each appliance. One may also want to consider updating any woodstove or fireplace insert which was not produced in the last 15 years. During that time incredible strides has been made in woodstove design making available woodstoves which when installed properly, burned properly, and cleaned annually are much cleaner and safer than those which produced larger amounts of creosote in the past.

As required by the national standard for masonry fireplace construction (NFPA 211), all masonry chimneys must have at least a flue tile in good condition installed within the masonry structure to exhaust combustion gases of the fireplace or appliances attached to them. If those flue tiles are improperly installed (misalignment is the most common problem), cracked from sudden thermal expansion, or missing due to poor chimney design the chimney is sub-standard and potentially dangerous.

In the case of a traditional wood fireplace or woodstove, creosote is able to pass though cracks or openings in the flue tiles and be absorbed into the porous masonry structure of the chimney. If this occurs, a chimney fire will not be contained inside the flue tile vent system with dangerous results a real possibility. In addition to possible creosote problems, cracked, missing, or poorly installed flue tiles can allow exhaust gases to seep though crack in the brick structure of the chimney into a home. This situation has the potential to lead to a carbon monoxide poisoning situation.

All natural draft chimney function due to temperature differences between the outside of the home and the exhaust gases. The draft created by this temperature difference draws the exhaust gases produced by a fireplace or appliance safely out of the chimney.

Most all fuels have as a by product of combustion elements which can condense when they come into contact with cooler surfaces. In the case or wood fired appliances and fireplaces, creosote is the condensing by-product. As shown in the picture to the right, creosote condensation can be substantial when conditions are right for condensation to occur. Creosote is the fuel for chimney fires. The best way to ensure a chimney fire will not occur is to not have the fuel for it in the first place. In the case of natural gas or propane fired appliances the primary condensate is water. This condensation can speed up water damage to a chimney via the freeze / thaw cycle. Permanent damage to a chimney can be cause cracks in the structure of the chimney leading to structural failure or exhaust gases seeping into living space.

The key to a condensation problem relates both to proper sizing of a vent system and its proper design and construction. This condition is a cool or cold flue. A cold flue which does not heat up properly is a surface ready to hold condensation.

Some have made claims of the superiority of one type of 316 stainless verses another. The simple truth is 316L and 316Ti are both excellent products. 316L has virtually the same amount of Titanium for high temperature stability as 316Ti but it also includes Molybdenum. This is what gives 316L greater corrosion resistance against low temperatures.

Low temperature corrosion is the most common reason why chimney liners fail over time. That is why we have chosen 316L as our stainless steel of choice for both our INTEGRITY™ (formerly CHIM-FLEX®) chimney liner and components, commonly called fittings. Unlike other systems that will mix and match the stainless steel, INTEGRITY™ chimney liner systems provide unbeatable protection from the top of your installation to the bottom.  

There are a number of ways to lock, or seam, a strip wound tube (which is what flexible chimney liner is). Some have made claims that the higher number of layers in the seam makes a better the seam. Just because there is a higher number of layers in a seam, material can still be cheated or pulled out of the seam to stretch inventory dollars. More material in the seams means it’s more expensive to produce; which is why this is the most commonly cut corner when producing chimney liner.

The machine we've chosen to manufacture our INTEGRITY™ (formerly CHIM-FLEX®) chimney liner creates a proprietary 7 layer locking seam. This type of seam construction and our manufacturing quality controls put more material where it counts, in the seam! More material in the seam gives our chimney liner more strength to withstand the rigors of shipping, installation, and thermal expansion and contraction which occurs from use.

The wall thickness is a key element in the flexibility and durability of chimney liner during the installation process. Too thin a liner may be suspect to shipping and installation damage; cheaper liner systems are usually manufactured from this wall thickness. Too thick a liner may be too stiff and difficult to install while adding unnecessary expensive to an installation.

We have chosen .0055 for our wall thickness because it is the perfect balance of flexibility and strength. CHIM-FLEX is the only chimney liner in the industry to be manufactured from this material thickness. Highly flexible, light weight and extremely durable we like to call it the Goldie Locks thickness. It's not too thin; it's not too thick, it's just right for every installation. .0055 also gives CHIM-FLEX the ability to easily be ovalized and taken back to round on the job site. Perfect for unexpected and narrow situations which means you can avoid expensive transition fittings which add undue cost to installations.

Our manufacturing tolerances are to .003 of on inch. The same tolerance and precision used in the aerospace industry! Simply put, this means INTEGRITY™(formerly CHIM-FLEX®) fittings fit right and fit every time.

INTEGRITY™chimney liner components, commonly called fittings, are all CAD (computer aided designed) and CNC (computer Numeric Coordinated) cut and formed for a perfect fit and finish. This is a big deal. Our commitment to highest quality components means a major commitment to equipment, technology and highly skilled labor force to ensure every part is identical to the one that was built before it; year in and year out.

Because we use CAD and CNC technology, INTEGRITY™components have also been purposefully designed by our engineers to be aesthetically appealing too. We don't just think of chimney liner systems as a commodity, we think of them as an investment in your home. If a liner system looks cheap, chances are it is. Aside from product quality, this is the most overlooked aspect by others in the venting industry today.

Steel mills create expanded metal mesh by a slitting sheetsof metal while it's still hot. Then the metal is stretched, or expanded, to create more material from a single sheet. This expansion creates a very inconsistant product with extremely sharp edges. Expanded metal mesh is very cheap to produce which is why it is used by almost every manufacturer, except to RLH Industries, Inc.

Our CNC punched mesh starts with a finished, single sheet of metal. We then program our machines using CAD to create our design; then our CNC turrret punch presses literally punch our mesh pattern into the solid material. This gives us the ability to form our products from a single piece of metal.

It is more expensive to produce because the inset portion of the mesh can not be used. However, our CNC punched mesh is extremely consistant and much stronger than expanded metal mesh. In addition, CNC punched mesh allows for a smooth, burr free edge that gives our stainless steel and aluminum fittings a look and feel that is only available with an INTEGRITY™(formerly CHIM-FLEX®) chimney lining system.

Underwriters Laboratories, Inc (UL) developed the 1777 standard for the US and S635 standard for Canada for testing chimney liners. UL subjects its submissions to days of rigorous testing and follows their listings up with ongoing quarterly inspections of the manufacturing plants to maintain the listing integrity.

Unlike UL, other testing agencies do not conduct ongoing inspections of the manufacturing facilities after the initial listing. This makes it easier to those manufacturers to cheapen their products comprosing safety along the way. Other testing agencies also allow chimney liner to be tested for only a part of the full standard and not to the entire standard set forth by UL.

INTEGRITY™(formerly CHIM-FLEX®) chimney liner systems are tested and listed by Underwriters Laboratories, Inc (UL) to their stringent UL 1777 standard for the US and ULC S635 standard for Canada for stainless steel chimney liner and 441 for aluminum chimney liner.