Home Chimneys??

[jttheclockman]

For those in the know about chimneys, a few questions. First I am talking homeowner chimneys. Forgive the not knowing names. But what are the red blocks that line the interior of a chimney. They are square and stack on top of each other and then block and or brick is built around them.

The reason I am asking is there now a law that if you replace your boiler or hot water heater and it is piped into the chimney then you need to have a steel liner inserted??? I have conflicting reports that if you chimney is lined with terracotta bricks then it does because they can leak gases. But if you have these red blocks and for a lack of a better name clay blocks you do not. Anyone with knowledge of new rules when installing a new furnace and or water heater. Or do you know the rules to when you need to install a steel liner?? I will be needing to do this next year. Thanks.

 

[Dieseldoc]

John: Contact the city/county permit Dept where you live , I sure they will update you on the regulations, and issue you a permit for doing the job.

 

[lorbay]

John they are called flue liners. The code for here in BC Canada any chimney or flue that will have a gas appliance inserted into the chimney shall have a liner installed from appliance to chimney cap.
Lin

 

[monophoto]

I suspect that this is very much a matter of local codes, and the best way to get a good answer is to contact the building inspector who has jurisdiction over your area.

But that said, if you are having the system replaced by a reputable contractor, he will almost certainly be familiar with the local rules and will recommend a suitable solution.

 

[Ted iin Michigan]

John - In the wayback times flue gasses (the products of combustion in our furnaces or hot water heaters) were pretty hot. That heated up the masonry chimneys (like yours) and that created an updraft which carried away all that stuff. As the furnaces and hot water heaters became more and more efficient, the heat in those flue gasses was captured and used to heat the house or hot water - a good thing. But the resulting gasses going up chimneys were a lot cooler and the water vapor and other things in the flue gasses condensed on the inside of the cool masonry chimneys (a bad thing). Those other things created mildly acidic conditions which ate away at the mortar binding the stuff together and also the liners (tiles). This resulted in the deterioration of the tiles which then fell into the chimney and over time blocked the gasses from escaping. Another bad thing which then forced carbon monoxide into the house. Lots of tragic stories there so, in response, many (not all) local codes have been rewritten to require the installation of a flue liner (stainless steel is common). There's not as much mass in a flue lioner so they heat up faster and carry away the products better and they resist corrosion better.
We always said there is always a story behind a rule. Most often a sad one.
Bottom line - best to comply with code.

 

[Fuzzy63]

John, If you have building inspector in your area they would no the codes for your area.
Gary