Cracked chimney repair and masonry work in Ybor City

Reading the whole chimney before any masonry work

A chimney is a stack of brick, mortar, a crown on top and flashing where it meets the roof, all working together. Damage in one part usually has a cause in another, so a sound masonry repair begins by looking at every part.

Our crew checks the brick faces, the joints, the courses at the top, the crown, the flashing and any earlier patches. We note which areas are sound and which are not.

That survey becomes the repair area on your estimate, so the work covers the damage without replacing masonry that still does its job.

The mortar types used on chimney masonry

Masonry mortar is classified under ASTM C270 into Types M, S, N and O, from strongest to weakest. BIA describes Type N as the general all-purpose mortar, Type S as stronger, Type M as very strong but hard to work, and Type O as a low-strength mix for interior and restoration work.

For chimneys, BIA recommends Type N, with Type S as the alternate. BIA points to Type M where masonry is in contact with the earth, and keeps Type O mostly for interior and restoration work.

Our masonry crew names the mortar type on your estimate and explains why it suits your chimney.

Why the strongest mortar is rarely the right mortar

It is tempting to think a harder mortar makes a stronger repair. BIA advises the opposite, choosing the mortar with the lowest compressive strength that meets the job's needs.

The National Park Service explains why: repair mortar should be softer than the bricks, so that movement and moisture are taken up by the joints, which can be repointed again, rather than by the bricks.

We match mortar strength to the brick and the old mortar, and avoid cement-rich mixes that are harder than the brick around them.

What your chimney masonry estimate should show

A masonry estimate is easier to trust when it answers specific questions about the work. Ask any contractor, including us, to spell these out.

• Which areas of the chimney will be repaired, and which are sound?
• Which bricks will be replaced, and which joints repointed?
• Which mortar type will be used, and why?
• How deep will old mortar be removed?
• How will the joints be finished, and how will the color be matched?
• What is being done about the crown, the flashing and the water source?