Do it Yourself Guide to Repointing Chimney Mortar

A crumbling chimney is a safety hazard and a detriment to your homes value. With a little bit of knowledge and some sweat equity you can repoint (replace) the chimney mortar yourself. Before you begin your project a word of safety is in order. Since chimneys are almost always in a high, difficult to access location, you need to be extra careful about ladder safety. Make sure that when you are putting up the ladder on the chimney that you stay clear of all power or utility lines. Coming into contact with any utility line could possibly cause death or serious injury. Also be sure that the ladder is firmly planted on level ground. Having another person there to steady the ladder and to pass items to you is also a good idea.

Some tools that you will need for this job are a cement or brick trowel, a brick jointing tool, a container to mix up some mortar, premade mortar mix, and a concrete brush. All of these items can be found at any Home Depot or Lowes home improvement stores. If you don't have a lot of mortar which will need to be replaced, you can purchase premixed mortar in a caulk tube like dispenser. This is nice for small jobs, and can make the application easier since you just place the tube in any caulk gun and you are ready to go.

Mix the mortar mix according to the manufacturer's directions on the package.

Begin working at the top of the Chimney. You want to check for loose bricks and loose mortar. It's important to start at the top because you don't want loose material falling down on you as you work below.

Remove all the loose mortar out of the joints. Ensure that you brush off any loose particles, as this will prevent the new mortar from having a good bond with the brickwork.

After the joints are cleaned out, begin packing the joints with new mortar using a brick trowel. Ensure that you get good coverage. It will take some practice so start in a small area until you get the hang of it.

After you have the mortar packed well in to the joint - use the trowel to cut off any excess mortar, and work to clean up the joint as best as you can with the trowel. After that you will want to shape the mortar joint using a brick jointing tool. This tool is run along the mortar joints to give them that classic concave look. Remember at this stage you are just trying to make the joint look uniform. Be careful not to scrape out too much mortar out of the joint with the jointing tool. As you work the joint you will want to try to compress the mortar as much as you can. If you need to add more mortar then you can add a little at this stage.

After the joints have set, you can come back and hit the brick face with a soft concrete brush - to clean up the job.