When your brick mortar is cracked, it is more than just unsightly. Water can work its way into the cracks, then freeze, expand, and separate the cracks even more. Sometimes, the brick mortar isn't just cracked: it is gone, having crumbled and fallen out over time. The inexpensive, traditional way of curing this is to repoint your brick.
While it sounds much like a task reserved only for masons, repointing brick mortar isn't all that mysterious or difficult. In fact, you only need a few basic tools and some mortar.
What Brick Repointing Is
Mortar is the filling between bricks that holds bricks in place. When the brick is originally laid, one of the last steps is to point the brick. Pointing the brick means grooving out the mortar and remove excess.
Repointing the brick mortar means to chip out the old mortar and replace it with new mortar. The reason the process is called pointing—or repointing, in this case—is because you use a pointed trowel.
If working on a brick chimney, use a fall arrestor or fall restraint system. Due to the loose mortar and dropcloth, it can be easy to trip and fall off of the roof. Wear safety glasses when raking (or chipping away) the old mortar.
Tools and Materials
- Joint raker or old screwdriver
- Wire brush
- Garden hose attached to a faucet
- Pointing trowel
- Margin trowel
- Cloth dropcloth
- Safety glasses
Rake the Brick
Raking the brick is a mason's term that means is to scrape out the worst of the mortar so that you will have a substantial base on which to place the new mortar. It is necessary to rake the brick mortar before repointing.
- Spread a cloth drop cloth below the brick surface.
- Use a joint raker or an old screwdriver to scrape out loose, crumbly mortar. The aim is not to remove all of the mortar but only to catch the high spots that are loose and weakened.
- Switch to the hammer and an old chisel or screwdriver. Gently knock out any stray pieces that you could not get with the joint scraper.
- Finish off with a wire brush to remove the remaining crumbs.
- If you encounter any cracked bricks along the way, you can remove them individually and replace them.
The mortar should have a firm consistency, much like peanut butter. You should be able to press your thumb into the mortar, with the thumb print remaining.
- Mix up the mortar in a bucket with the margin trowel. Don't mix up a lot of mortar, in order to keep the mortar from drying up on you.
- After mixing the mortar, let it sit for about 30 to 45 minutes.
- Spray down the bricks and mortar with a garden hose.
- Let the water soak into the bricks for about 15 minutes.
- Scoop some mortar onto the hawk. Keep the amount small: just about a baseball-sized mound of mortar.
- Hold the hawk below the brick, just under the area that will be repointed.
- With the pointing trowel, scoop up a small amount of mortar and press in the new mortar.
- As mortar drops down, mix it back into the original mound on the hawk and reuse it on the brick.
- Before leaving an area, use the pointing trowel to create a groove in the mortar with the hawk underneath to catch remnants.
Tips For Repointing Bricks
- Work only in small sections to avoid having the mortar dry up on you before you can point it.
- When raking the brick, have the garden hose near you (if working on exterior wall brick) and frequently mist the brick to keep the dust down.
- Also when raking, if it's hard to chip away parts of the mortar, that likely means that the mortar is good enough to remain.
- Take it slow and be patient. Repointing bricks is interesting for the first few bricks, then the work becomes tedious.
- If working on a large project, set small goals for yourself every day. Set your mind on getting that whole wall done over a course of weeks or months, instead of a weekend.
- Be careful not to chip or gouge the brick.
- Repoint the brick in temperatures between 40 and 90 degrees F. When the mortar gets too cold, it becomes brittle. When the mortar is too hot, it dries out quickly.