Chimney Repointing Experts Since 1980's. Fully Insured.
We serve Vancouver, Surrey, Langley, West Vancouver, North Vancouver, Burnaby, Coquitlam, New Westminster, Abbotsford, Maple Ridge, Chilliwack, Mission, entire Lower Mainland and Fraser Valley. We have expertise in repairing leaky chimneys, numerous homes, commercial projects, fireplace and more.
Repointing is the process of renewing the pointing (the external part of mortar joints) in masonry construction. Over time, weathering and decay cause voids in the joints between masonry units (usually bricks), allowing the undesirable entrance of water. Water entering through these voids can cause significant damage through frost weathering and from salt dissolution and deposition. Repointing is also called pointing, or pointing up, although these terms more properly refer to the finishing step in new construction.
Sound mortar normally does not need to be removed from a building during the repointing process, although such a practice is common. New mortar can be designed to match the color and texture of existing mortar to avoid visual aberrations. The repointing process begins by removing damaged pointing to a depth equal to or slightly more than the width of the joint, or to the point where sound mortar is reached. Depths greater than 2-1/2″ or 4 cm would be filled in several passes, allowing the mortar to cure for at least 24 hours. The joint profile would be as rectangular as possible as the new pointing mortar should be allowed ample opportunity to bond with the masonry unit.
Removal of old mortar between joints is done carefully to avoid damage to masonry units. On very old buildings with soft materials, such as under-fired brick, removal by hand is often the most effective to avoid damage. Hard Portland cement mortar is usually removed with a grinder or power circular masonry blade, taking care not to damage the masonry units. Vertical joints are done by hand or with small power chisels.
Poor repointing work often raises the level of the mortar joint above the face of the masonry unit, which causes the mortar edge to feather. Such a process is aesthetically undesirable and can cause performance problems as a thin layer of mortar will quickly erode. In addition, depending on the nature of the mortar, mortar that rises above the level of the face of the masonry unit can participate in damaging the arris or corner of the masonry unit. In these cases, deteriorated mortar is often not removed to a sufficient depth.