What is a Chimney?

A chimney is a system for venting hot flue gases or smoke from a boiler, stove, furnace or fireplace to the outside atmosphere. It is typically vertical to ensure that the hot gases flow smoothly.

Most are tall to increase their draw of air for combustion. They are traditionally built of brick in both small and large buildings. In earlier days they were made of a simple brick construction. Later ones were constructed by placing the bricks around tile liners.

The space inside the chimney is called the flue. This can be one or more vertical passage ways. These flues may be construced of terracotta, clay or steel.

To control downdrafts, venting caps are sometimes placed on the top. These caps come in a variety of styles and are most commonly constructed from stainless steel.What is a chimney cap?

Proper design is needed to accommodate the volume and type of exhaust being emmitted by the appliance it serves. This involves correct sizing, adequate height, proper consruction and the use of appropriate building materials.

                 What is a chimney cap?

Chimney caps not only protect the inside of your chimney but are also designed to protect the mortar crown area at the top of the chimney.

Why do I need a chimney cap? The most important reason for capping your chimney is to protect the inside of your chimney from water which can lead to moisture damage.

Capping your chimney will reduce the risk of burning embers or sparks from escaping the open chimney top and landing on your roof or in your yard.

An uncapped chimney is an open invitation to birds and animals to “nest” inside your flue. These “nests” block your chimney flue and can result in a chimney fire.

How do I determine what kind of cap I need? Caps for chimneys come in many different styles and sizes. To determine what style is best for your application you will first need to know what kind of chimney you have.

If you have a masonry chimney determine next if you have a single flue or a multiple flue.

If you have a single clay liner sticking out of your masonry chimney, measure the top of the clay liner. These dimensions will determine what size cap will be needed.

What's involved in a flexible chimney liner installation?

A flexible chimney liner installation always begins with an inspection of the existing masonry chimney. A thorough cleaning of the chimney should be done prior to the installation of the chimney liner to clear any obstructions. It's best to install the widest liner possible to get the best draft possible.

Most flexible liner installations are done from the top of the chimney down, however it is also possible to do the flexibleliner installation from the bottom up. It all depends upon each unique situation and the preference of the installer. Sometimes the liner may need a little coaxing to get it all the way through the chimney, but its flexible nature allows for quite a bit of contorting.

Depending on the type of application you have, the instructions for the chimney liner installation will vary slightly. In this article you will learn the basic instructions for installing a flexible stainless steel chimney liner.

Step by step installation instructions

Preparing the liner for installation

CAUTION: Metal edges can be sharp. Be sure to wear protective gloves when handling the liner and liner components. Also make sure your chimney has been cleared of all debris before installing the liner.

1. Remove the liner from the packaging and straighten it out on a flat surface.

2. Attach the bottom termination connector (tee or other appliance connecting device). Tighten the hose clamp of the connector to the liner. Do not over tighten.

3. Find the exact length of the liner needed by measuring from where the bottom termination will stop to the top of the chimney crown. Add one foot. Cut the liner using a pair of tin snips. Be cautious as to not leave jagged pointed edges on the liner. Make sure to leave a clean edge for safety purposes.

Installing the liner

1. Make sure you have the availble manpower in order to handle the liner. Always take safety percautions when doing any work on the roof.

2. Some installations may require you to use a rope connected to a pulling cone or direcly to the bottom connector. A second person may be needed to pull the rope from the bottom of the chimney while the person on the roof guides the liner down the chimney.

3. Keep the chimney liner centered in the chimney opening to avoid causing damage to the insulation and/or chimney liner.

4. Once the bottom connector has reached the desired position, cut the top of the liner. Add 4 inches to the height that is equal to the crown.

5. For longer lengths of liner exceeding 35 feet, it is recommended that the liner be supported. This can be done with angle iron supporting the bottom connector.

Completing the bottom termination

1. Locate the point where the connector pipe will pass through the chimney to the tee body.

2. If insulated, cut away a hole in the insulation and mesh where the tee snout will connect to the body of the tee.

3. Secure the snout to the body of the tee using the attached metal band which wraps around the backside of the tee body.

4. If insulated, wrap the snout of the tee with insulation.

5. Fill in the hole around the snout with brick and mortar.

6. Complete your connection to the heating appliance following all applicable codes.More on the two part tee

Completing the top termination

1. With the bottom connector in place, put a heavy bead of silicone caulk around the chimney crown or top of clay flue tile. Place the top plate over the liner and press firmly into the caulk.

2. Tighten the hose clamp band around the liner. This secures the liner to the top plate. Optional: Top plate flashing has four pre drilled holes which can be used to tap-con the top plate to the crown.

3. Install the cap by fitting it over the collar of the top plate. Tighten the hose clamp band of the cap onto the top plate collar. Your top termination is now comple."

NOTE: If the application allows, the liner should be insulated. This is a step that is often avoided, but is a good idea. An insulated chimney liner will allow for the liner to get heated properly which allows for a better draft.