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Today we’re going to fix the crumbling mortar in this brick siding using a process called repointing. Be sure to wear leather glovers and safety glasses. The instructions in this video use mixture mortar, but you can also use quick-n-easy caulk tubes meant for outdoor mortar. Just be sure to follow the manufacturer’s instructions.

If you have extensive cracks in your brick wall, it's a good idea to rent a pneumatic chisel from your local independent home improvement retailer to speed up the process.

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When the mortar in your brick siding starts to crumble, like you see here, it’s not something you should put off fixing. Gaps between the bricks can allow moisture to penetrate behind the wall, which can lead to all sorts of problems, like excessive moisture in your wall cavities and eventually, mold. While you could call a mason to fix the problem, it’s a relatively easy project to tackle yourself ... and inexpensive too if you have the right tools and materials. And everything you need, including the advice, is just a short trip away to ... you guessed it ... your local independent home improvement retailer.

Today we’re going to fix the crumbling mortar in this brick siding using a process called repointing. First we’re going to remove the old cracked mortar by chiseling it out. Then we’re going to mix up a batch of new mortar and place it between the joints in a way even the ancient Romans, who invented the technique, would be proud of. Finally, we’ll smooth it out so you can’t tell that it was ever repaired in the first place. .... So let’s get started.

This ¼" cold chisel is the prefect tool to dig out the old mortar. To start chipping out the mortar, start in the middle of the joint and angle the chisel at about 30". Then slowly chip away. Also be sure you’re wearing thick leather gloves and safety glasses for this step. As you continue chipping away at the mortar, increase your angle to dig deeper. Remember, we need to make sure the mortar is chiseled out to a depth of 1". This is probably the most important step in the process and is the difference between a repointing job that will last for years, and a tuck-pointing patch job, where new mortar is added over the old cracked mortar without removing it first. No doubt, chiseling is hard work, and takes a lot of time. Lucky for us we caught the problem early, and only have a small section to do.

Pointing or tuckpointing trowels, as they are often called, come in different widths to match the width of the mortar joints between the brick. Be sure to pick up a couple different sizes close the width of your mortar joints.

Once we’ve chiseled to a depth of one inch, we’ll check it with this metal ruler. That should do the trick. The next critical step is to make sure the mortar channel is as clean as possible and that all dust and loose debris is swept out of the joint. We’ll use this stiff bristled brush to start cleaning out the joint. Then, a shot of air with a compressor will remove any remaining dust. Now the mortar will have a surface free of debris to which it can form a secure bond.

As you can see, chiseling and cleaning out mortar joints is hard work. If we had a house full of cracked mortar joints, we would consider renting a pneumatic chisel from our local independent home improvement retailer to speed the process along.

Now it’s time to mix up a batch of our repair mortar, carefully following the manufacturer’s instructions. We’ll mix it up with our margin trowel in this bucket, adding water sparingly until we reach the desired consistency. That’s just about right. Once the mortar mix can stick to the bottom of our trowel without falling off, we know it will stick to our joint.

Before we start filling the joints with our mortar mix, we’ll mist the brick and the joints down to wet them slightly. This will help the mortar cure without drying out too fast.

To get the mortar into the joints takes a little practice. First, put some mortar along the length of the drywall taping knife, close to the side. You can also use a drywall hawk. Then, holding it up just beneath the joint, we’ll use our tuck pointing trowel to push the mortar into the joint. This is where you don’t want to get into a big hurry. Several thin layers of mortar spread out over several hours is better than pushing a big glob into the joint all at once. It only takes a few tries to get the technique down, and once you get the hang of it, it will seem easy for the rest of the project.

When we reach the desired thickness, we’ll use this brick jointer to smooth and shape the joint, trying to mimic the look of the existing joints as best we can. Like pointing trowels, brick jointers come in different sizes to match the thickness of your mortar joints. The concave shape it leaves behind helps shed water away from both the brick and the mortar joint itself, which will prolong the life of your brick siding.

While this is a tried-and-true method that has been used for centuries, there are some products available that come in both caulk tubes and squeeze tubes ready to apply to the joint. Just be sure to prep the joint the same way and read and follow the manufacturer’s instructions carefully.

The last thing we need to do is re-mist the area and cover our work for a couple days to keep the joints moist, so they will cure properly. After re-misting the area with a spray bottle of water, this plastic trash bag taped over the area will do the trick. While the repair mortar mix we’re using may feel dry to the touch in a few hours, after repointing, it will take a good month for it to reach full strength.

There you have it. Now admit it ... that was easier than you thought it would be, and it was kind of fun, too. The best part is now that we know the basics of repointing, we’ll be able to fix problems as they arise in the future and keep our brick siding looking great for years to come.

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  1. 1.chisel out mortar

    Chisel out the broken mortar to a depth of one inch. Shallower depths won't last as long.

  2. 2.clean area

    Clean out the area with a stiff bristled brush.

  3. 3.clean area

    Clean the are further with an air compressor to remove any remaining dust.

  4. 4.mix mortar

    Mix up your batch of repair mortar according to manufacturer's instructions. At the right thickness, it should stick to the bottom of the trowel without falling.

  5. 5.mist area

    Mist the area to keep the new mortar from drying out too quickly.

  6. 6.add new mortar

    Place some fresh mortar along the length of the drywall taping knife, close to the side.

  7. 7.add new mortar

    Hold the knife just beneath the join and use the tuck pointing trowel to push the mortar into the joint.

  8. 8.smooth out

    Once at the desired thickness, use a brick jointer to smooth and shape the joint. Try to mimic the look of the existing mortar.

  9. 9.mist area

    Spray some more water on the repaired area. Do this for a couple of days.

  10. 10.cover up

    Cover the new are for a couple days to allow proper curing of the mortar.


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