Spalling brick repair for chimneys in Pebble Creek

Choosing the mortar that goes around new bricks

Around replacement bricks, the Brick Industry Association calls for a mortar whose physical properties resemble the existing mortar, and it warns that the wrong mix can make the surrounding masonry spall and crack. It generally recommends Type N for modern work and Type O where a more cement-rich mortar would be too strong.

Color matters too. BIA suggests comparing new mortar samples with the existing mortar both wet and fully dry, since mortar changes color as it dries.

We match the mortar to the chimney rather than reaching for the strongest bag available, and describe the result you can expect.

When brick damage points to a bigger problem

Some patterns are not about individual bricks. The Brick Industry Association lists cracks through multiple units, cracks following a stepped or diagonal pattern, widespread spalling and masonry that has moved out of plane among conditions that can indicate a structural issue, which generally warrant an engineer's investigation.

Replacing a handful of bricks does not fix movement or widespread deterioration. If we see those patterns, we say so and explain the options, which may include a larger rebuild of the affected section.

Being honest about that early saves money spent on repairs that would not hold.

How the repaired chimney will look

New bricks set into weathered masonry will look different at first, even when the match is good. The new mortar can also look brighter than joints that have aged for years.

We discuss the likely appearance before any work, including the size of the repair area and the mortar color. Over time, the new work tends to blend in, but we do not promise an invisible repair on day one.

If appearance matters most on a particular face of the chimney, tell us, and we will take extra care with the match there.

Hairline cracks and open cracks

Not every crack means a brick must come out. A fine hairline crack at the surface behaves differently from an open crack that runs through the face of the brick. The Brick Industry Association notes that a water repellent cannot keep water out of cracks wider than 0.02 inch.

Cracks extending through the face shell are one of the conditions BIA says call for removing and replacing the brick. We measure and describe the cracks we find, so the recommendation rests on what is actually there.