The flue lining of a chimney is either a
ceramic, clay, or metal conduit that is intended to keep in the combustion
products and move them to the outside, protecting the chimney walls from
corroding overtime. Installing flue
liners in chimneys has been recommended for over one hundred years. In fact, ever since the 1940s, chimneys have
been tested for their durability due to increasing concerns over safety
issues. It was discovered that chimneys
that were unlined were unsafe.
Chimney Liner
Functions
There are
three main functions to chimney liners:
1.
The liner has to protect the home
from heat transfers to combustibles.
Studies have shown that unlined chimneys that allowed heat to move
through the chimney did so at such a rapid pace, that wood parts of the home
held adjacent to the chimney could catch on fire in only a few hours.
2.
Chimney liners also protect the
masonry from corrosion. In the same
studies, it was discovered that flue glasses could easily penetrate through the
mortar overtime, and the overall lifespan of the chimney would be dramatically
reduced. This is because flue gasses are
naturally acidic, and therefore can chew away at the mortar joints from the
inside, causing it to erode. The more
heat, the more flue glasses, and the faster the corrosion.
3.
A chimney liner is intended for
is to provide a rightly sized flue to maximize the efficiency of the
chimney. Modern stoves, appliances and
furnaces require a rightly sized flue in order to maximize their own efficiency. The chimney allows combustion products to
move outside of the house, but at the same time, the draft that is produced
from the same chimney allows the appliance to be supplied with combustion
air. Therefore, a chimney liner that is
not the correct size can result in heavy erosion and creosote build-up.
Types of
Chimney Liners
There are
three main types of chimney liners:
1.
The most common - clay tiled
chimney liners. These are the most popular due to the lesser expense and being
easy to maintain. However, the only downside that you have to trade off is that
they are ceramic products, and therefore they are not the most effective at
distributing heat.
2.
Cast-in-place chimney liners are
very lightweight and are installed inside of the chimney. They are very smooth
and seamless, and also extend chimney life. They are suitable for all fuels
burned in the fireplace or furnace.
3.
Metal chimney liners - made out
of either aluminum or stainless steel, are well known for their safety and
durability.
