March 2011 – Page 2 – Ask the Chimney Sweep

Grinding out deteriorated mortar. My roofer told me that my chimney needed pointing, or tuck-pointing. What exactly does the mean? Sherry C. Albany, NY Sherry, We often get calls from customers asking for a tuck-pointing estimate or asking exactly what tuck-pointing means. Basically, this is the process of removal of damaged or deteriorated mortar from between the bricks. The purpose of the mortar is to hold the bricks tightly together and to keep the moisture from entering into the brick wall. When the old mortar is removed, new mortar is then placed or tucked back into the open joints. This is done by the use of a tool called a pointing trowel. This is where we get the term tuck-pointing. In the past, tuck-pointing was performed with simple hand tools such as chisels, pointing trowels and a hock that held the mortar for the mason as he was installing the new material. Most contractors today use electric right-angle grinders, plastic grout bags and still use the trusty old pointing trowel, to push that new mortar material back into those open voids. A couple of things to ask your proposed contractors are regarding the mortar color and sand mixtures. Ask them how are they going to attempt matching the old mortar on your home? Due to the age of your home as well as weather conditions, there may be different shades on existing brick and mortar facings. Many times in our tuck-pointing work we will use gray and buff color dyes or even black to tone down the harsh look of new mortar work. Mortar color dye pigments should consist of metallic oxides and not organic chemicals. We use a much coarser grade of sand, as standard masons sand is actually easier to work with, but is just too fine in texture and will finish out very shiny in appearance. Before the mortar full sets or hardens, a final tooling is required to create a concave water resistant mortar joint. To further provide for that weathered restoration finish we will use a wooded dowel or stick, to finish off what is called the tooling of the new mortar joints. Filling mortar joints with an icing bag. The size of the aggregate or sand in many older homes was of a more coarse texture, and it may actually have been obtained from a nearby creek or riverbed. Look for contractors who not only are experts, but are able to blend materials and match colors, so that the final mortar joints match the existing brick work. Over the years I have found that many bricklayers do a great job on what is called new production work, but lack the attention for detail that is needed for quality restoration projects. If your tuck-pointing job is done properly, it will provide for water-resistant mortar joints that will extend the life of your brickwork for many years to come. A sloppy tuck-pointing job is hard to clean up after and could actually depreciate your property value. Choose your contractor wisely!!