Chimney Draw – 10 Steps To Improving Draft

Here, we’ll be discussing how to increase the draft in a chimney. If you’re currently having draft issues, you’ll find this article an interesting read.

What more? The corrective actions to restore or increase the draft in your chimney aren’t difficult.

There are several ways of improving your chimney draw and we’ll show you what they are.

During combustion, certain things occur in a fireplace that a lot of homeowners are unaware of. Now, fire needs air or oxygen to burn. Without it, you can bet that the fire will go out.

Chimney draw is the area we’ll be focused on. Join us as we attempt to provide as much information about this term as possible.

You’ll also discover the importance of chimney draw and how best to improve it. The aim is to help homeowners improve fireplace combustion.

What’s Chimney Draw?

Chimney draw is one action that happens seamlessly without notice.

However, when impeded, it affects fireplace combustion. It simply refers to the process where the air is drawn from a room to replace hot gases or smoke which are combustion byproducts.

It’s a continuous cycle that ensures that combustion is sustained while waste gases or smoke are pushed out or ejected. As smoke rises into the chimney from your fireplace, it creates a pressure difference that needs to be balanced.

This is where fresh air needs to be pulled from within a room to balance out the pressure difference.

In a situation where chimney draw is affected, you’re likely to have a smoky chimney. This is a situation where your home starts to behave like a vacuum.

In other words, negative air pressure leads to downdrafts that fill up your home with smoke. A simple solution will be to find ways to cancel out the negative pressure.

Also, if you think the draw in your chimney isn’t the way it should be, you can improve such a draw in many possible ways.

3 Common Chimney Draft Problems

Several factors could prevent a chimney from drafting properly. So, whenever a malfunction occurs, it’s necessary to identify and solve such a problem.

Chimney draft could be reduced or affected by the following;

Inappropriate Stovepipe Configuration or Sizing

A stove having a certain vent collar size must have a corresponding connector pipe size. The connector pipe or stove pipe connects the woodstove to the chimney.

Here, the stovepipe shouldn’t be too small or too large. It must be appropriately sized to allow for proper drafting.

Incorrect Flue Size

What’s the size of your fireplace opening?

There’s a close relationship between the cross-sectional area (CSA) of the masonry flue and that of the fireplace opening. As such, the CSA of the masonry flue should be at least 1/10 of the fireplace opening.

When the flue size is incorrect, it affects the normal functioning of the chimney, thus leading to a decrease in the draft.

Blocked off Chimney Flue

All sorts of problems affecting normal chimney functioning are likely to occur. This includes a blocked-off chimney flue. Birds are likely to build nests in chimneys.

This affects basic functioning thus leading to problems like a decrease in the draft.

Some other problems that are likely to affect the draft include a dirty chimney cap, structural issues or damage, and creosote buildup. This is as far as we’ll go in mentioning causes of chimney draft.

We’ll shift our focus to the topic being discussed; how to increase draft in chimneys.

How To Increase Chimney Draft

Lots of ways to improve chimney draw exist. Although different, each serves the same purpose.

These include opening up windows or air vents, sweeping the chimney, using a fireplace grate, pushing combustion further back, as well as leaving glass doors open before every fire.

Other ways of improving chimney draw include opening the damper, burning smaller, yet hotter fires, using dried or seasoned logs, warming up before lighting the fire, and following the top-down approach to fire lighting.

Does a taller chimney draw better? Yes. Chimney height can impact draw capacity.

Here is how to increase draft in a chimney:

  • Burning the Right Fuel

This sounds vague on the surface.

However, the specifics provide a better understanding of how combusting the right fuel improves the draft in the chimney. Now, if there’s a good fuel, there’s also bad fuels.

The wrong fuel type we’re referring to here is unseasoned, wet, or greenwood.

When wet wood is burned in a chimney, the amount of heat generated isn’t sufficient enough.

Now, you’ll need sufficient heat for air to rise and be replaced by cooler air. This has a direct negative impact on the draft as smoke and gases remain in the room.

Now, the best solution for improving draft issues, in this case, will be to change the fuel. Use dry seasoned wood for enough heat to be generated during combustion.

  • Chimney Construction Problems

When a chimney isn’t built by a professional, there are bound to be problems. Such problems range from the incorrect firebox to flue ration, wrong fireplace manufacture, and a shallow firebox.

A shallow firebox causes smoke leakages as it enters your room instead of going up the flue.

What more? Flue angles are critical to the smooth functioning of a chimney.

As such, when chimney passageways or flue aren’t vertical enough, it creates a problem. There may not be enough force to expel heat from the chimney.

All these are bound to result in issues that affect the smooth running of your chimney. Structural problems with the chimney design are a bit complex to deal with for the homeowner.

As such, it’s best to seek the help of an expert.

Having a chimney sweep take a look at your chimney will help a lot in identifying the specific problem and solving it. Sometimes, certain corrective actions may be necessary concerning the structure.

Here, the help of an expert is the most reliable way to go about solving the problem.

  • Promoting Stack Effect

The stack effect depends heavily on air buoyancy. This is largely influenced by a difference in indoor-to-outdoor air density. The result is the improvement of natural ventilation and by extension combustion.

For example, where there’s another air-guzzling appliance in the room asides from your chimney, then it’s likely to result in draft issues.

Air vents are examples of such.  Generally, when these work at the same time as your chimney, it leads to air imbalance which results in a backdraft or negative pressure.

So, to increase the draft in the chimney, all you need to do is improve the stack effect by putting off the other appliances.

Usage of such appliances can be planned for when the chimney isn’t in use.

Sometimes, all you have to do is keep a window open to let in the air.

  • Making Sure the Ratio between the Firebox and Chimney Flue are Correct

This is a bit more technical and requires the input of a chimney expert.

When the ratio between the firebox and chimney flue is off, it’s followed by a decrease in a draft. When chimney sweeps come around, they look at all possible scenarios including the ratio between firebox and chimney flue.

Any imbalance or faults are rectified to improve the draft and smooth functioning. A DIY procedure for rectifying these faults isn’t recommended as it’s best left to the experts.

  • Removing Any Blockages

One of the problems we earlier mentioned as being responsible for chimney draft issues is flue blockage.

Here, animals look for places of warmth in your chimney and end up building nests.

A chimney sweep will have to inspect such areas and clear any blockages. This action instantly improves the draft in your chimney making it work smoothly.

  • Opening up Windows or Air Vents

A well-insulated home has many advantages.

However, this can become a problem sometimes when using a chimney. Insufficient draw results when there’s a lesser supply of fresh air to replace expelled smoke and gases.

Whenever you notice inefficient draw conditions in a chimney, quickly open up a window or external air vents however little. This action lets insufficient air replace or neutralize the imbalance.

  • Sweeping the Chimney

A chimney needs to be swept as frequently as possible.

This is to help remove soot and creosote deposits, thus preventing chances of accumulation.

If you have been worried about why your chimney does not draw correctly, here is one. Also, sweeping a chimney every year helps get rid of animal nests that may be present within your flue.

  • Using a Fireplace Grate

Consider burning your logs in a fireplace grate. This action helps lift your fire off the base of your firebox. What happens is a situation where air easily gets under and through the fire, thus helping with better combustion.

Also, the fire is suspended close to the base of your firebox.

Using a grate also elevates the fire to burn higher. This leads to better air heating within the chimney which generally improves draw conditions.

  • Pushing Combustion Further Back

The further back you light a fire in a fireplace, the more it improves draft.

What more? You the chimney tends to be warmed better than usual. This condition discourages the condensation of exhaust fumes or creosotes on the chimney flue lining.

  • Leaving Glass Doors Open Before Every Fire

Quite a lot of newer designs come with fireplace glass doors.

If yours has one, you can easily improve chimney draw by leaving the glass doors open before starting a fire.

This action is aimed at promoting room temperature conditions at both fireplace and chimney.

A fireplace that’s too cold may become a challenge when trying to start a fire. As the fireplace and chimney get warmer, it becomes easier to start a fire as there’s sufficient draw after leaving the glass door open for some time.

  • Opening the Damper

Whenever combustion is completed, dampers are shut to help retain the heat created.

To start another fire, such a damper needs to be wide open. This must be kept open for as long as the fires remain. This plate mostly found just above the firebox needs to be kept open before starting the fire.

This applies to other dampers located higher up the chimney structures. Ordinarily, you can’t physically reach those dampers. However, their handles go down the chimney and can be easily operated.

  • Burning Smaller, Yet Hotter Fires

To make the fire lighting much quicker, it’s necessary to start by building a small fire. This results in a situation where the fire gets hotter and the likelihood of going out is reduced.

Chimney draw is also improved creating a stable fire in the process.

  • Using Dried or Seasoned Logs

Dried or seasoned log use is one important aspect of combustion that easily improves chimney draw. Woods having high moisture content are much more difficult to burn.

With less heat being produced due to high moisture content, there’s less chimney draw occurring.

For wood to burn efficiently, its moisture content must be below 20%. You won’t have to deal with excess smoke resulting from wet firewood.

  • Warming Up Before Lighting the Fire

As a strategy to improve chimney draw, you’ll need to warm up the air within your chimney before igniting the fire. Most times, cold air gets trapped within a chimney which can arrest combustion exhaust gases from getting out.

To prevent such from happening, you’ll need to do a bit of warming up. Using a newspaper, roll up a sheet and light it up. However, you’ll need to hold it up until it burns out.

This should be enough to warm up any cold air within the chimney.

  • Following the Top-Down Approach to Fire Lighting

Here, fire is built by starting the fire from the top and allowing it to burn right through to the bottom.

This improves draw and ensures the fire is started much faster. Place your logs first before applying kindling and other lighting materials.

As the initial heat gets generated, it helps further warm up your chimney air, thus promoting a draw.


The chimney draft is a crucial process that takes place any time a chimney is being used. It can be referred to as a pressure difference that draws in air needed to sustain combustion while expelling exhaust gas.

Now, many things could go wrong that may affect the chimney draft.

When draft reduces, combustion is affected and the chimney malfunctions.

Chimney draw can be improved by implementing any or all of these strategies. These are ways that help limit draw issues which are quite common in many homes.

These are ways to increase the draft in your chimney. Before now, we considered the common problems leading to such issues.

In a nutshell, certain remedies can be taken by the homeowner to rectify a draft problem while for others, the help of a professional will be required.

3 thoughts on “Chimney Draw – 10 Steps To Improving Draft”

  1. I recently replaced an old fireplace grate and the “tiles” in the bottom of the fireplace with new cinderblock-type squares to raise the grate high enough for a good draught. Unfortunately, the new 3-inch-deep blocks and new, heavier grate make cleaning a nightmare. If I take out the blocks, I’m wondering if the fire will still draw correctly. The bottom of the basket part of the grate would be about 18 inches from the bottom of the flue if the blocks were gone. Is that too much space for correct draw? (Putting wood on the grate adds about five inches.)

  2. I have two firerplaced in my home. One in livingroom other down in basement , below and right under the livingroom fireplace. What air direction is needed. It smokes. One time had three capes on chimney now two. Is this a air problem.


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