Danger - Do you smell smoke in the house when you use your fireplace or stove? If you do, and your have more then one chimney in the same masonry enclosure, please read this site carefully!

5.17, Masonry Institute of America - "The pouring of smoke from one flue to an adjacent flue occurs where downdraft from interior suction or vertical wind currents force smoke down an inactive flue as it exhausts from the adjoing flue"

5.14, Masonry Institute of America "The top of a flue should have a height differential...as much as 12 inches to prevent smoke from pouring from one flue into the other flue"


Sadly, the chimney caps you see above were installed by "professionals" who claimed to have the homeowners best interest in mind. Instead, they failed to fix gross violations of proper chimney design and actually created a situation where smoke, carbon monoxide and other dangerous gases can enter the living area. Here is our Boost-A-Cap solution, which brings a chimney up to spec and allows for installation of two caps next to each other.

Quotes from those who know!

"Flow Reversal or Down drafting chimney -- This is the most common problem I have run into in my 20 years of business. A typical phone call comes in from a customer saying "I'm trying to light my stove and the whole house is filling up with smoke" - Craig Issod, Publisher of HearthNet

"I have a problem with reverse flow on my chimney when I crank down my wood stove in the basement. The smoke comes down the other flue for the fireplace even tho I have a damper cap on top" - Todd W, Chippewa, WI.

"Received the Boost-A-Cap on Wednesday. Super service and incredibly fast delivery. Exactly what we were looking for at a reasonable price! Terrific!"

Typical note from Customer who purchases and installs Boost-A-Cap:
I just wanted to drop a quick note to outline my experience with your product.  Last year I had three chimney caps installed by a professional chimney sweep. You can imagine my surprise the first time i fire up my upstairs chimney to find smoke coming out my downstairs fireplace filling the downstairs with smoke. Upon searching the internet I came across your site which outline why this problem occurs (three chimney caps of the same height). I called your company and was able to gather more information on why this problem occurs and had one of your professionals walk me through the best options to solve the problem.

I purchased the Boost-A-Cap product and gave it to my chimney sweep to install. Never having used such a product he refused to install it. Even after I explained what was occurring and how the product would fix the situation, but as they say you can't teach an old dog new tricks. Taking the situation in hand I followed the included direction(very simple) and installed the extend-a-flue myself. I am happy to say the problem has been solved and I am once again able to use all my fireplaces safely.

So once again thank you for your professionalism, patience and a great product. I will definitely recommend your product to my neighbors. I will also be looking for a new chimney sweep!!!