Can A Brick Fireplace Be Load Bearing?

Can A Brick Fireplace Be Load Bearing? (Five Factors)

Whether your chimney is loadbearing/structural or not should be a major concern.

If you want to make major changes to the chimney or remove it completely, you should first investigate whether the stability of the roof, ceiling, or the rest of the building will be affected.

So, Can A Brick Fireplace Be Load Bearing?

Yes – chimneys do serve as load bearers in some situations. For any element on your home to qualify as a load-bearing structure, it should (among other things) be an active structural part of your building holding most, if not all, of the weight exerted by elements above it. The load-bearing element should proceed to release the weight (plus its own) to the foundation structure beneath it. Oftentimes, load-bearing elements such as walls are constructed first at the beginning of the home’s construction.

This may sound counterintuitive but load-bearing chimneys are not limited to supporting overhead weight. They can – in very rare cases – be used for floor joist connections as well.

Still, just because your chimney has ticked all the right boxes to qualify for a load-bearing role doesn’t mean it’s competent enough for the role. There’s just a lot of unrelated factors to consider.

So What Makes A Load Bearing Chimney?

1. The Local Code Permits It

The first thing to look at before anything should be your local building code.

Building requirements for the construction of chimneys vary between regions, but a few requirements stay the same across different regions.

For instance, most codes demand that neither flue nor chimney liner should change shape or size within 6” (about 150 mm) of either rafter, floor components, or ceiling components.

However, some codes are explicit, either restricting or permitting the owner of the building to offload the overhead weight on the chimney.

So, if you are planning to use the chimney for this purpose, consult your local building code and even hire an experienced engineer to provide further guidance.

2. You Will Only Use Silicate Bricks Inside/Outside The Chimney

Ordinary chimneys with no load-bearing role are typically built using calcium or clay bricks.

Of course, each brick comes with unique durability depending on the detailing of the chimney and/or mortar.

The interior of these structures doesn’t require extra reinforcement.

Load-bearing chimneys, on another hand, use slightly different kinds of bricks on the inside (sometimes both on the inside and outside).

The interior of these structures is often made of silicate bricks.

This group of bricks is preferred for two reasons – they hold up against the overlying load better than traditional bricks and endure the searing heat rushing from below just as perfectly.

Note that how the silicate bricks are installed can vary between regions depending on the codes among other things.

For instance, some places may restrict silicate bricks to the interior of your chimney rather than both interior and exterior.

However, whether they are inside or outside, it’s pretty standard for a structural chimney to have a corrosion-resistant, acid-resistant sleeve made of stainless steel in the duct.

3. A Chimney Can Be a Structural in Absence of a Beam (But Must Be Built for The Job)

The easiest way to identify a load-bearing wall is to look for the presence of beams.

If you don’t see one or several beams running across the roof them, then you can conclude you are dealing with a bearing wall.


Because beams are normally tasked with offloading the overlying weight to the farthest support points and finally down to the foundation.

So the presence of beams would mean the job has been taken care of.

The same concept applies to your chimney albeit in a little intricate way.

See, there are only two situations when a load-bearing chimney would be necessary:

  • When a load of considerable weight such as a water tank or air conditioning equipment is housed somewhere in the attic but close to the position of the chimney
  • When the roof or joists are considerably heavy close to the position of the chimney in such a way that it would be more sensible to let the chimney support that section than add a load-bearing wall or beam

Considering that beams are seldom installed in residential buildings (unless the home is storied and must support great overhead weight), both of the above 2 situations are very likely.

These situations call for a chimney specially built chimney for the job.

Firstly, the walls of your load-bearing chimney must be built from concrete or solid brick plus the aforementioned silicate bricks (can be inside but preferably outside).

Secondly, and most importantly, the thickness of the walls of the chimney should be at least 4” (or 12” thick if it consists of stone) up to the point it rises past the ceiling or position of the load.

4. Structural Chimneys Are Taller and Sit On Ordinary Footing/Foundation

Only tall chimneys can be structural.

Short chimneys are undesirable even if load-bearing is out of the cards. For instance, short chimneys don’t draw as efficiently as their tall counterparts.

However, when it comes to load-bearing roles, tall chimneys are highly advantageous as well but there’s a limit.

For the chimney to perfectly dissipate the overlying weight to the foundation or nearby wall, it needs to be about 12 feet tall.

Chimney foundation is another factor to put into consideration.

For the structure to effectively support whatever type of overlying load, the footing should be better than ordinary.

Footings for such chimneys and their accompanying masonry fireplaces must be built from solid masonry or concrete, at least 12 – 14” thick.

It can be a little thicker depending on the size of the load. Furthermore, it should extend more than 6” past the face of your foundation wall or fireplace on all sides.

Just as important, the cross-sectional part of the chimney needs to be roughly the same size as the area of the outlet of the stove but should not be three times larger in any circumstance.

5. More Evidence That A Chimney Is Load Bearing

  • The chimney is on the exterior wall at or near the middle. Exterior walls can be load-bearing in their own right but can be reinforced with a chimney
  • The chimney is perpendicular to your floor joists. If it’s close to beams, then chances are very high it’s structural.

Signs That The Chimney ISN’T Load Bearing

  • The base (or breast) meets the bare minimum requirements for an average chimney
  • The floor joists run parallel to the wall that holds the chimney. This is especially true if the chimney is on the exterior wall.

Note that Identifying load-bearing structures – both walls and chimneys – is getting harder today because of the new advanced and better framing materials.

This means most of the rules of thumb we used a few decades ago no longer apply.


So, can a brick fireplace be load-bearing?

Yes, certainly. However, the first thing to look at should be your local building code.

Building requirements for the construction of chimneys vary between regions, but a few requirements stay the same across different regions.

A chimney can be structural if a load of considerable weight is housed somewhere in the attic but close to the position of the chimney.

If the chimney is on the exterior wall at or near the middle, it’s likely to be load-bearing.


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