How to Repair Broken Chimney Mortar

What You'll Need
Protective glasses
Protective mask
Wire brush
Quick setting mortar

When you have a chimney there are special things you need to look out for such as broken chimney mortar. This home repair is not one of those things can be swept under the carpet. Damaged chimney mortar can cause some very real problems such as fires. Large holes in chimney mortar can allow burning cinders an access point to the home. Smoke can also be an issue with damaged chimney mortar. Either of these problems, among others, is very dangerous. Aged, broken, cracked or incomplete chimney mortar has to be repaired and this article will show you how.

Step 1: Locate Damaged Chimney Mortar

Inspect the chimney thoroughly both inside the home and outside. Carefully touch the mortar. Mortar should feel somewhat pliable or soft to the touch. Old mortar will simply break and crumble. Other spots of damaged chimney mortar will easily be spotted as it will have already broken off and fallen.

Step 2: Clear the Chimney Mortar

Use the wire brush and remove the damaged chimney mortar from between the bricks. This not only removes all of the bad chimney mortar but prepares the chimney for new mortar. Make sure that you wear the protective mask and glasses as you do not want to inhale mortar dust or chimney dirt. You also do not want this stuff to get into your eyes.

Step 3: Repairing Chimney Mortar

You are actually completely replacing the damaged chimney mortar. It is important that you do not reuse bits of old mortar because the chimney will not be stable. Mix the mortar in the bucket according to the instructions. Chimney and fireplace mortar is not like normal mortar so make sure you are using mortar specifically created chimneys and fireplaces. Put mortar on the trowel. Slide the loaded trowel across the application area of the chimney. Get as much of the mortar between the bricks as you can. You want to fill these cracks and not just seal the space. You do not have to be completely flawless for this as you will need to make more than pass with the trowel. Continue with this step until all areas of the chimney that need repair gets chimney mortar.

Step 4: Finishing Up

Working with chimney mortar is a messy and rather inaccurate job. You will wind up with mortar on bricks where you do not need it and this all right because, until the chimney mortar sets, it is easy to clean. Place a clean towel in hot water and wring out the excess. Rub the area where chimney mortar needs to be removed and the wet chimney mortar will easily wipe off as the excess water will thin the mortar. You can use a damp towel to smooth the chimney mortar between the bricks. This not only will create a nicer appearance but push the chimney mortar deeper. Allow the chimney mortar to completely set. You can then brush away the excess debris with a paintbrush.