What happens during a repointing or concrete repair job?

Updated November 11, 2026 · KeystoneProGuide editorial team

What does a careful repointing job look like?

It is slower than many owners expect, and most of the time goes into preparation and curing rather than laying mortar. The clearest public description of careful practice is the General Services Administration's (GSA) specification for repointing historic federal buildings. Your house does not need a federal specification, but the steps show what good work involves, and you can ask a contractor which of them they follow.

What happens before work starts?

• Test areas. The GSA starts with small test patches in inconspicuous spots, then a larger sample area that is repointed and left to cure before approval. The approved sample becomes the standard the rest of the wall is judged against.
• Matching the mortar. The GSA has the existing mortar analyzed and the new mortar matched to it in color, grain size and texture, with a strength no greater than the original mortar or the surrounding brick or stone.
• Cleaning first. Where the masonry is to be cleaned, the GSA cleans it before repointing, using the gentlest method that works, starting with water and soft brushes.
• Protection. Windows, doors, woodwork and plants are protected, sills and ledges are covered against drips, and the work area is closed off with cones or tape. Under the GSA specification, damage caused by the work is the contractor's to put right.

How is the old mortar removed?

By hand, as far as possible. The GSA has joints raked out with chisels and mallets, to a depth of at least 2.5 times the joint's height but never more than half the width of the brick, and with a clean, square back so the new mortar bonds. A 1/2-inch joint, for example, is cut back at least 1-1/4 inches. Shallow, feathered raking is not accepted.

Power tools are allowed under conditions. The GSA permits a narrow saw blade down the middle of hard portland-cement bed joints after a successful demonstration, but not on the short vertical joints between bricks, where a rotary saw can over-cut into the masonry. The National Park Service (NPS) shows what poor work looks like: mortar smeared beyond the joints, and joint width and tooling that do not match the original.

If grinders are used, dust control applies. The Occupational Safety and Health Administration's silica rule calls for a shroud and dust collector on tuckpointing grinders and a respirator for the operator, and bars dry sweeping of the dust where wet methods or HEPA vacuums would work. Cleanup by vacuum or wetting, rather than a dry broom, is what the rule describes.

How is the new mortar put in?

The GSA's sequence is:

1. Rinse the joints so they are damp but have no standing water.
2. Pack mortar in by hand with pointing tools. Joints deeper than 3/4 inch are filled in layers, each left until it is "thumbprint hard" before the next.
3. Tool the joints to match the original profile.
4. Brush off excess mortar with a stiff natural-bristle brush. Metal brushes are not used.
5. Keep the mortar damp for at least 72 hours, under wet burlap and plastic if needed, with misting.

Weather matters throughout. The GSA does not point when temperatures will fall below 40 degrees F within 8 hours, in heat above 100 degrees F, or within 24 hours after rain. If your mason stops for the weather, that is part of doing it properly.

What about a concrete job?

For new paving, footings or a wall, the day starts before the crew arrives. Pennsylvania 811 sends utility locators to mark buried lines with colored paint, flags or chalk, and the marks must stay visible. You are responsible for them once the locator leaves, and if they are disturbed, 811 must be called to re-mark. Customer-owned lines, such as a cable to a garden light, may not be marked.

Inspections may be part of the schedule. Lower Merion Township, for example, requires its inspector to look at the forms before concrete is poured for a sidewalk replacement, and to make a final inspection afterwards. In Philadelphia, inspections are scheduled through L&I once the contractor is ready.

For repairs to existing concrete, the GSA's patching specification has all unsound concrete removed down to sound material, any exposed steel cleaned and primed against rust, and the patch kept out of traffic and weather until it has gained strength. It also says patching compound is not to be used to bridge cracks or joints that still move.

How long does it take?

No source gives a duration for a house. What the sources do fix are minimum waits: 72 hours of damp curing for repointing under the GSA specification, 14 days of curing before a GSA mockup is approved, and the lead time for 811.

How do you check the finished work?

• New joints match the old in color, width and profile when seen from a distance.
• No mortar is smeared on the brick faces.
• No hairline cracks in the new mortar or gaps at the joint edges. The GSA treats those as defects to be cut out and redone.
• The site is swept and the debris gone.

Before the work, questions to ask covers what to settle in writing. For timing, see how often and when. Contractors are on the masonry contractors page.

Sources

1. Repointing historic masonry, U.S. General Services Administration
2. Cleaning historic masonry, U.S. General Services Administration
3. Installation of concrete patching compounds, U.S. General Services Administration
4. Common Problems with Brick Masonry, U.S. National Park Service
5. 1926.1153 - Respirable crystalline silica., U.S. Occupational Safety and Health Administration
6. Silica, Crystalline - Construction, U.S. Occupational Safety and Health Administration
7. Homeowners, Pennsylvania One Call System (Pennsylvania 811)
8. Sidewalk Installation and Replacement Guide, Lower Merion Township
9. Get a Building Permit, City of Philadelphia