How to Clean Fireplace Mortar for Best Results

Updated September 20, 2021
cleaning fireplace

Cleaning your fireplace can be a battle. Not only are your arms and shoulders sore, but how are you supposed to get the soot out of the mortar? To make that mortar sparkling again without blowing out your shoulders and back, explore a few simple cleaning methods for how to clean light, medium, and heavily soiled fireplace mortar.

Instructions for How to Clean Fireplace Mortar

The best technique for cleaning the mortar on your fireplace varies based on how much cleaning is necessary to get the look you want. If too much time passes between cleanings or if you are going for a spotless look, cleaning will likely be more difficult than if you perform regular maintenance or if you will be satisfied with a look that indicates that the fireplace is used frequently.

Mortar Cleaning Materials

Before starting your mortar cleaning adventure, you need to grab a few materials depending on your preferred method.

  • Mortar cleaning solution
  • Baking soda
  • Salt
  • Magic Eraser
  • Bristle brush
  • Old cloth
  • Borax
  • Rubber gloves
  • Goggles
  • Masonry cleaner

How to Clean Mortar Using Fireplace Cleaning Solutions

If you prefer to use a cleaning solution, it's best to look for one that's not acidic. One such option is Fireplace Brick Cleaner, an all-natural, nonacidic, non-abrasive, and non-flammable cleaner that can be used on fireplace bricks, stone, and mortar. This method can work for medium to heavy stains.

  1. Spray the affected area and watch the black marks that appear on fireplaces with normal use disappear.
  2. Wipe the area, and you are done.

Both smoke marks and creosote disappear before your eyes when you spray them with this cleanser. You won't have to scrub or use abrasive cleaning tools to remove the unsightly stains you want to remove from your fireplace.

Create a Mortar Scrub

If you don't have a mortar cleaner on hand, you can create an abrasive scrub to clean the mortar stains. However, this method works best on light stains.

  1. Use a wet Magic Eraser pad to remove as much residue as possible.
  2. Mix equal parts baking soda and salt into a bowl.
  3. Add water to create a paste.
  4. Apply the paste to the mortar.
  5. Allow it to sit for ten or so minutes.
  6. Scrub it with the bristle brush.
  7. Wipe down.

How to Use Borax to Clean Fireplace Mortar

If the baking soda and salt aren't cutting through the issue, you have medium stains that need more cleaning power. In this instance, you'll want to grab the Borax.

  1. Mix warm water, a few drops of Dawn, and two tablespoons of Borax in a spray bottle.
  2. Spray the mixture on the affected mortar.
  3. Scrub the area with a bristle brush.
  4. Repeat until clean.
Man cleaning out fireplace

Clean Your Fireplace Mortar With Acid

In some cases, there may be so much build-up on mortar that using an acidic solution is necessary. If you decide that you need to go this route, avoid using muriatic acid if at all possible. While some people use muriatic acid solutions to clean fireplace mortar and bricks, it's advisable this dangerous and corrosive substance should only be used for fireplace--and any household--cleaning as a last resort. If you need an acidic cleaning solution, choose a masonry cleaner made with phosphoric acid instead. The risks are significantly reduced with this type of solution, and it can be effective on all but the most severe of stains.

How to Clean Fireplace Mortar Without Chemicals

While many people reach for a chemical solution first when it's time to clean, in many cases doing so is unnecessary when cleaning fireplace mortar if you have the right tools and are willing to use some elbow grease.

  • If you have a Dremel tool with a wire brush or wire wheel attachment, you can use it to remove smoke stains from the fireplace mortar.
  • Sandblasting is another non-chemical answer to how to clean fireplace mortar, but this method should only be performed by an experienced professional.

Additional Fireplace Maintenance Tips

In addition to keeping the mortar on your fireplace free from black marks caused by smoke and soot build-up, it's also essential to keep the bricks, enclosure, and chimney clean and to vacuum out to the soot regularly. In addition to keeping your fireplace looking its best, taking care of these important household cleaning tasks help ensure safe operation of the unit. You can also use these tips for fireplace maintenance.

  1. Check the chimney regularly.
  2. Use seasonal wood for the best burn.
  3. Remove creosote build-up regularly.
  4. Clean your fireplace bricks and mortar regularly to avoid heavy stains.
  5. Have your fireplace inspected yearly to ensure everything is working well.

Keep Your Fireplace Sparkling

Cleaning your fireplace mortar can be difficult. And when dealing with chemicals like acids, you want to always take the proper precautions with handling any dangerous chemicals like using goggles and rubber gloves. Now it's time to get that mortar sparkling again.

How to Clean Fireplace Mortar for Best Results