As we discuss on our chimney repair page, an unlined chimney can be very dangerous. Houses built to code since the 1950s have terra cotta tiles or other flue liners, but these degrade over time, or suffer damage from earthquakes, chimney fires, or other extreme conditions. Even minor cracks in flue tiles can allow sparks, heat, and toxic flue gasses to escape into your home; the results can be anything from damage to the structural integrity of your masonry chimney, to carbon monoxide poisoning, to a house fire.
There are a variety of ways to reline a damaged flue to a masonry fireplace. Our preferred method is the HeatShield® flue repair system. Rather than a full poured liner, the HeatShield system is a high-temperature Cerfractory® material designed to fill mortar joints, cover cracks, or resurface your entire terra cotta flue. After determining the extent of repairs needed to your flue, Wooden Sun will use a foam applicator, custom-sized for your flue, to extrude the Cerfactory material into any joints that are missing mortar in your flue. If there are further cracks in the flue tiles, a second layer of the Cerfactory material can be applied to resurface the entire liner. Once dry, the HeatShield Cerfactory cement is rated to withstand temperatures exceeding 2900°F, well beyond the temperature reached by most chimney fires.
But how does the HeatShield system differ from the poured liners that Wooden Sun doesn’t install? Good question, and there are two primary differences. The first is that poured liners often require a lot more material to get a less durable liner, and a great deal of special equipment, which makes them more expensive than the HeatShield system. The application of the HeatShield Cerfactory material requires relatively little by way of installation equipment, and can therefore be installed at less expense than a full poured chimney liner. Additionally, the HeatShield system is specifically designed to address multiple levels of flue damage. Many poured or cast-in-place liner systems are intended for unlined chimneys, or terra cotta flues with such severe damage that the tiles have to be removed completely. However, most of the damaged flues we encounter during our regular service work are mostly sound, but are missing some or all of their mortar joints, or have cracks running through otherwise intact flue tiles. In these situations, our certified HeatShield installers will use only the amount of Cerfactory material needed to seal the damaged surfaces of your flue tiles, rather than creating what is essentially a new flue inside your otherwise intact chimney. While any damage to the flue presents a danger to the home and its residents, the HeatShield system gives us the flexibility to target the specific problems within your flue, without requiring you to spend money fixing a problem you *don’t* have.
Fire is a volatile thing, and not even the best sweeps, installers, or masons can ensure that nothing will ever go wrong. At Wooden Sun, we believe in taking every precaution to make sure that the heat and smoke of your fire are safely ducted outside so that the rest of your home is as protected as it can possibly be.