Can you repoint over old mortar?

Can You Mortar Over Old Mortar? If your brick is 50 years old or less, you can probably repoint it safely with modern, portland cement–based mortar (although the guy doing the next repointing, who'll have to grind it out, may curse your decision).

Do you have to remove old mortar before repointing?

The chisels will break the bond between the Portland-based mortar and the brick or stone. In repointing brick usually the repointed joints are less than an inch deep, so removal is safe as long as care is taken with the faces of the masonry units. Remove mortar at least 2x the height of the joint.

Can I put new mortar over old mortar?

Applying fresh mortar on top of old mortar that is loose or falling out will do little or no good; enough of the old mortar must be removed to make room for a layer of new mortar that is at least half an inch thick, and even then it is important to make sure that what is left of the old mortar is still solid and ...

What is the difference between tuckpointing and repointing?

Repointing is the process of removing damaged mortar joints and renewing them. Tuckpointing is quite similar but is not always completed for damage control. Tuckpointing by definition is a style that uses two different colors of mortar to alter the appearance of mortar joints, this is an important distinction.

What happens if you don't repoint brickwork?

Failed or unsuitable pointing

The more modern mortar could trap moisture and so prevent it escaping via the mortar joints. This, in turn, would force the moisture to emerge on the brick faces, where it could be frozen and then lead the brick surfaces to crumble.

How to repoint old brickwork

How do you get old pointing out?

All the old pointing material will need to be removed before you can re-fill the area. To remove the pointing, use the plugging chisel in the hard to reach areas of the joints and the lump hammer and bolster to loosen the majority of the existing pointing.

How do you bond mortar to old concrete?

When using a liquid bonding agent, paint the bonder onto the existing concrete and allow it to dry until it is tacky. This usually takes only a few minutes. Then apply the repair material. After the bonder has become tacky, apply a scratch coat as described above and then apply the repair material.

How do you fix crumbling mortar?

The best way to fix crumbling mortar is by doing a process called repointing and applying a sealant on its surface. This procedure can be efficiently done by an experienced mason or by yourself.

What causes mortar to crumble?

Crumbling or failing mortar can be caused by a number of reasons: Failing mortar can usually be attributed to a lack of carbonation of the lime within the mortar meaning that the mortar will have little if any, strength.

What depth should repointing be?

As a general rule, the pointing to be repaired must be dug out to a minimum depth of about two-and-a-half times its thickness, in other words ¾ inch to one inch for regular 3/8-inch pointing. You need to dig at least ¾ inch deep for thinner pointing.

Can you sand down mortar?

Use it to sand thinset the same way you would use a sandpaper-wrapped wooden block. First, sand up and down and then side to side using strong, even pressure. Wipe away the dust every few minutes, or use a hose attachment to vacuum it away.

Is brickwork easy to repoint?

Repointing is a straightforward job and the materials required are not expensive — but the cost of the labour involved in brickwork repointing can be quite high. It can also be hard to find a builder willing to take on small repointing jobs, which is why many people choose to carry out repointing on a DIY basis.

What is the correct mix for repointing?

A typical mortar mix for Repointing purposes, for use in an area subject to normal weather conditions, would comprise 1 part Portland Cement, 1 part Lime and 5½ parts Sand.

Why is my pointing cracking?

Pointing Dried Too Quickly

In hot conditions, the pointed mortar may dry up too quickly. This also takes out the moisture too quickly from the mortar. If the pointing dried out too quickly than it usually does, it can weaken the strength of the mortar which can cause cracks in the pointing.

What type of mortar is used for repointing?

Type O mortar, or high-lime mortar, a softer mortar with a low compressive strength of 350 psi, is best suited to repointing for several reasons. The first reason is that type O mortar is softer than the older bricks, and it allows the bricks to expand or contract from temperature changes or stress.

What will happen if mortar is not cleaned?

8. What will happen if the mortar is not cleaned off from the tools? A. The mortar will build up and harden.

Can you clean mortar off bricks?

Brick mortar is an alkaline material. You can dissolve alkaline compounds with acid. A simple example of this happens to be hard water spots. These white splotches on plumbing faucets and countertops can be quickly cleaned up with regular white vinegar you have in your home.

How deep should you grind mortar out for tuckpointing?

All grinding work at AAA-1 Masonry & Tuckpointing calls for mortar joints to be ground out to a minimum depth of 3/4 inch.

Can you repoint brick in the winter?

Repoint only when temperatures remain between 40 and 90 degrees Fahrenheit, even at night. Cold makes mortar brittle, while heat dries it out and prevents hardening. Keep fresh lime mortar damp for at least 3 days so it can harden before it dries.

Will repointing stop damp?

You can do this yourself, or have a professional complete the work for you if it looks like it might take too much time. Repointing is one of the crucial steps in removing penetrating damp from your property.