How to construct a Chimney – A step by step guide

With winter right around the corner, it’s time to start thinking about constructing a new chimney. Whether you’re replacing an old one or adding a second one for your growing home, this is something that can be done by anyone with basic masonry skills and tools. 

In this guide, we will take you through each step of the process so that you are ready for the cold season ahead!

Safety Codes

A chimney should be built in compliance with building codes. The chimney liner was often omitted from older chimneys. As a result, this condition was considered very dangerous. The liner is a must part of every chimney nowadays.

Chimney Placement

It’s not just about the design of your home when it comes to installing your chimney and hob in the right place. According to expert like if you want a chimney that works well in cold weather, then installing it along an exterior wall is not recommended. An extremely cold winter climate can cause a cold stake of air in that chimney which makes it harder to start the fire. It keeps the chimney warm, no matter how incredibly cold it might be outside if the chimney is enclosed within the home’s structure.

Correct Height

Regardless of the chimney type you are going to build. In order to be sufficient, it must extend two feet above its peak. Moreover, it should extend at least three feet above the point where the chimney attaches to the roof. A proper height of the chimney is necessary to ensure combustion fumes are carried out of the house through its chimney. Additionally, it is a matter of safety in order to remove fire risks.

Wall Thickness

Masonry chimney walls must be minimum four inches thicker, and flue is not included in it. To protect the chimney from environmental elements, the outer walls should have a thickness of at least eight inches.


Masonry chimneys are typically the weightiest parts of a house. A footing of concrete 8 inches to 12 inches deep must be laid directly below the chimney, near the home’s foundation. There must be minimum six inches of clearance around the chimney’s edges. There is no special foundational support needed for factory-built hobs and fireplaces.


For your chimney and fireplace opening, the flue lining must have measurement and height correct and appropriate.

Factory-built appliances must be connected to a flue over a chimney in accordance with the manufacturer’s guidelines. Using the incorrect size flue can cause an appliance to malfunction. By keeping combustibles out of extreme heat conditions, the flue safeguards the home.

It is also required to keep masonry chimneys at least two inches away from all sides any explosive materials, in addition to a correct flue lining.


It is important to use insulation around and inside the chimney, if you use your fireplace as a heating source and not only for decoration.