Residential Chimneys

Buyline 9126


Paul Ahrens first applied his imagination to the development of new masonry chimney technology in 1924. Since that start, nearly 75 years ago, the family owned company has grown to become the largest manufacturer of chimney components and relining systems in Europe.


Today AHRENS has many locations in Germany, Austria, Switzerland and the United States that have installed over 1,000,000 chimney systems. In addition to having developed leading technology in chimney reconstruction, AHRENS has become the major manufacturer of concrete chimney accessories.

Seven decades of AHRENS research and development have produced a complete chimney product line that reflects the German attention to detail, simplicity of application and insistence on quality.


We have a knowledgeable staff on hand, waiting to analyze your situation and help you arrive at the best solution possible without obligation. We'll make sure you get our full support from the planning process through installation.

AHRENS has available the following professional evaluation and consultation services :

  • Video Inspections
  • Computer Sizing Analysis
  • Specification Assistance
  • Special Mix Design
  • Steel Reinforcement Design


The AHRENS U.L. Listed product is for low heat type chimneys with a maximum continuous appliance outlet flue gas temperature of 1000 F. (538 C.) listed in Column I & II of the NFPA 211 Chimney Selection Chart.

Appliances such as but not limited to :

  • Residential Heating Appliances
  • Commercial Heating Appliances
  • Fireplaces
  • Steam Boilers
  • Dual Fuel Appliances
Other Applications :

  • High Temp-to 3000 F. (Special Material) NFPA 211 Column III, IV & V
  • Historical Projects with specially designed mixes
  • Seismic & hurricane reinforcing
  • Vertical shaft repair (Non-Chimney)


As masonry chimneys age, the elements take their toll. If caught in time, the exterior of the chimney can usually be preserved by using techniques such as tuckpointing.

But, perhaps the worst enemy of masonry chimneys is the deterioration from within. Acidic condensation created in the combustion process can cause chimney damage that is not always visible until it is too late. Airborne pollutants can combine with the natural by-products of combustion to form these acidic and corrosive exhausts which "eat" away at the masonry.

As outdated heating systems are replaced by newer, more efficient systems, the problem is multiplied. Venting higher efficiency units into large unlined chimneys produces more acidic condensation and increases damage caused by freeze/thaw cycles. The alternative for large oversized flues is to increase the amount of heat that goes up the chimney so condensation does not occur. This alternative naturally has a negative effect on appliance efficiency and cannot be considered.

Regardless of the cause, if this deterioration is ignored, there will eventually be only one solution, tearing the chimney down and rebuilding. AHRENS offers a better approach!


AHRENS Chimney Technique is a unique two liner system for lining or relining masonry chimneys installed only by trained authorized AHRENS dealers. In chimneys old and new the AHRENS system will provide the following benefits regardless of the type of fuel being burned.

  • Properly sizes the flue to the appliance
  • Improves appliance efficiency
  • Insulates the chimney
  • Reduces and controls condensation
  • Repairs interior deterioration
  • Structurally strengthens



© 1997-2008 AHRENS Chimney Technique Inc. | All Rights Reserved
e-mail : ahrenschimney@qwestoffice.net

AHRENS Chimney Technique