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Top Ten Mistakes Made in Masonry Repair

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When you have settling cracks in your brick walls, you need to get them repointed. This process is known as tuck pointing. However, before you make any attempts at repairing this yourself or hiring the repairs done by a contractor or handyman, you should know the top ten most common mistakes made in repointing mortar.

The first mistake is having the repairs made before checking for additional problems. Repairing the cracks in the mortar and brick before checking the foundation or other problems that occur can result in more damage to your home and to your masonry siding.

Settling cracks occur due to the foundation settling and applying stress to the bricks. This makes them a common symptom of foundation repair and can help in understanding where and how much movement of the foundation has occurred.

To tuck point the mortar and replace broken brick along these settling cracks limits the ability to accurately repair the house foundation. Performing these repairs often results in damage to the brick walls when the foundation is repaired. Any mortar or bricks placed in these cracks to fill the gap become a wedge and force the opposite crack to form in the area and the brick tend to push out at corners of the house causing brick walls to crack, lean away from the house, or come off the foundation entirely when the house is lifted.

It cannot be stressed enough to check for other problems with the structure or foundation of the home before repairing mortar cracks.

The second most common mistake made in fixing settling cracks in brick is choosing a foundation repair company to level your foundation. There is a difference between leveling your foundation of your house and fixing your foundation problems.

There has never been a house foundation built perfectly level that I am aware of, and to level the foundation under your house would apply stresses to your home and cause more problems with your foundation. This in turn would create more cracks in the bricks and mortar joints around your home. When they stress the word level and use a computerized level for their readings, it is a strong indication that they intend to try leveling your foundation even if it causes more problems. If they focus on lifting, stabilizing, adjusting, and use the cracks in the mortar and brick to acquire their range of movement in the house slab, then they are likely taking more accurate details about the movement and have a better chance at providing quality foundation repair services.

The third common mistake in brick repair is using these tubes of mortar repair caulking in an attempt to repair the cracks yourself. While caulking is used around doors and windows and in expansion control joints to seal the wall and still allow movement, they are not intended for use as the mortar and can cause other damage to the brick.

The caulking will never look like the mortar and tends to be difficult to clean off of the faces of bricks due to their texture. The same is true of many other masonry repair products. They contain adhesives, epoxy, and other add mixes that can be hard to work with and difficult to remove. It often requires removing all of the brick in areas where these products are used to repair the brick. If you want to repair the mortar cracks yourself, you should use a proper repointing mortar with the same composition as the original. These are not bulk items they are custom made for matching your mortar composition, and require a mortar matching analysis of your existing mortar samples.

The fourth masonry repair mistake is how you match the mortar. This is not to be confused with matching mortar color. Mortar matching is the process of analyzing samples of the mortar to identify their composition, performance, and formula. As the color of sand and other materials in the composition effect the color, they are related, but the base formula of a mortar composition must be matched before any attempts are made to match the color of an existing mortar.

The mortar composition and formula are the guide to making a proper repair mortar and maintaining the formula. This is important because if the mortar is mismatched and has a different composition than the original mortar, it can have complications that make the color more difficult to match, cause damage to the bricks, prevent the new mortar from bonding with the old mortar, and could allow the wall to fall if the mortar crumbles.

The fifth most common mistake in repairing masonry is matching mortar color. Most of the time the mortar composition analysis of the original mortar is skipped and general assumptions are made in its place. This causes difficulty in matching mortar color because the color is a direct result of the composition and the ratio of materials in the mortar mix. To match the color of a mortar, you need to first match the formula and composition of the existing mortar.

After you have the base formula and composition, you can adjust the mortar color by adjusting the colors of base materials and adding pigments as needed. However, a common error is adding pigments or other materials too fast or changing the formula base. You must adhere to the base formula to maintain the performance and type of mortar being produced, and remember to add all portions slowly as you can continue to add but are unable to take anything back out.

In masonry repair, the sixth common mistake is the depth of repairs. A patch or bandage covers the top of a problem, but to repair the cracks, you need to remove some of the existing mortar. It needs to be removed to a depth that allows for a good bond of the new mortar to the old mortar and the bricks. This will help to ensure a lasting masonry repair. Generally, a good depth is about 1/2-3/4 of an inch deep into the mortar joints. More is better especially when the gap allows you to replace the entire mortar joint.

The seventh item where errors occur is in preparing the cracks for repointing. Dust and debris remaining in the cracks prevent the new mortar from bonding to the old cement and prevent the mortar joints from filling completely. It is important to brush away any loose debris or dust and rinse and moisten the old mortar. This will help the new mortar bond to the existing mortar.

The eighth mistake commonly made is in mixing the mortar. Too often, water is added rapidly and exceeds the amount needed and attempts are made to adjust this. The most common attempt to correct this problem is to add sand or mix to the mortar. When you do this, the composition formula is changed and the resulting mortar will not meet your requirements.

If you add too much water, you must add more of the entire composition materials based on the formula to adjust this without changing the ratio and mortar type. It is best to add water or pigments slowly as you cannot remove them, and when mistakes like this occur, you might be better to dispose of the mortar and start again.

The ninth most made error in tuck pointing is filing the mortar joint completely. When filing the mortar joints, they may look full, but they must be packed in to the mortar joints tightly. Dust and debris can prevent this and should be cleaned out before installing new mortar.

When mortar joints are not filled completely, they tend to crumble when pressure is applied. This is often noticed during tooling the mortar joints if the mortar has began to stiffen in the wall before jointing or tooling takes place. If this is noticed, remove the mortar where it occurs and replace it again. Also, remember that begin to stiffen does not mean let it get hard before tooling the joints. Applying pressure to dry mortar that hasn’t cured will cause cracking or crumbling of the mortar and will need replaced again.

And the tenth most common mistake in brick mortar repair is tooling and brushing the mortar joints. As I previously mentioned, tooling must be done as the mortar begins to stiffen but before it gets too hard for tooling. However, when tooling the mortar, it is important to match the existing type of tooling. There are all different designs for the tools that shape the mortar joints. The most common design is a rounded or raked mortar joint. You will want to use a jointing tool that produces the correct design and size of mortar joint. These tools come in wider angles for thicker mortar joints.

This is important to making the repairs blend into the wall. Using a jointer that doesn’t match will cause the mortar to cast a shadow at the intersections of new and old mortar. This also occurs with the mortar tags or excess mortar that are pressed out furring tooling. You must brush the excess away and blend the edges of each and every mortar joint to make the repairs match properly.

As you can see, masonry repair is a very detailed process where slight variance of any detail significantly changes the out come of the repairs.