Waukesha County Home

Dear Jim: We use our wood-burning fire- place for heat. It has not been cleaned out for years and we noticed bad spots on the outdoor chimney brick. What maintenance steps can we do ourselves? — Michelle B. Dear Michelle: There are some mainte- nance items you can do yourself, but you must first have the chimney flue profes- sionally cleaned by a chimney sweep. A cleaning also includes a complete inspec- tion. Thousands of homes burn to the ground each year from chimney fires. The bad outdoor spots on the chimney should be checked, but are not as serious as issues inside the chimney. The most com- mon problem is creosote deposits from too little combustion air or burning too much unseasoned firewood. Creosote is extreme- ly flammable when it gets hot inside the chimney. Many homes have small chimney fires from creosote buildup and the homeowners are not aware of it. If you have ever noticed a sudden increase in the fireplace draft, this is a sign of a chimney fire. The heat from the creosote burning creates the strong draft. When there is a creosote fire in the chim- ney, even a small fire, it can damage the mortar and break some tiles. If cracked tiles fall across the flue and block the air, this causes heavy smoke back drafting. You will definitely notice this if it happens. A more serious problem is the slow dete- rioration of the mortar between the chim- ney tiles from repeated smaller fires. This can allow the fire itself or just the intense heat to penetrate the chimney and start the wall framing on fire. Wall framing may be burning for quite a while before you notice it. If you are sleeping and don't have smoke detectors, this can be catastrophic. Another sign that there is creosote buildup and there have been some chimney fires is puffy black pieces that fall into the fireplace. Creosote is a hard material when cold, but when it burns, it puffs up and feels somewhat like chunks of black polystyrene foam. It crumbles very easily when it is touched. When the chimney sweep runs brushes up and down inside the chimney, it will def- initely knock the puffed creosote loose if there has been a fire. When the cleaning is done, the entire length of the chimney is inspected with a small video camera. Each mortar joint and tile can be carefully checked this way. Before hiring a chimney sweep, ask if he will do a camera inspection that you can watch. If the chimney sweep immediately suggests you need a new chimney liner without doing a camera inspection, be skeptical. Installing a new chimney liner, especially with some of the newer tech- niques, can cost thousands of dollars. Once the chimney is professionally cleaned and no internal problems were found, exterior and cosmetic problems are easy to repair yourself. Professional chim- ney repair products are available in small- er quantities for do-it-yourself use. When working on a roof or high on a ladder, always make sure to wear a harness that is secured to the structure and have a helper support the ladder. You may think that brick and mortar are very hard, but they are permeable to water. Over years of exposure, outdoor moisture can penetrate and deteriorate the mortar as you have noticed on some posts. This is most common in regions with many freeze/thaw cycles over winter. Using a chisel and hammer, tap on the suspected bad mortar spots. It will come loose easily if it is bad. Fill the pits with special plastic-based mortar repair com- pound which matches the color of most mortar. Next spray or brush the entire chimney exterior with liquid water repel- lant. When there is deteriorated mortar, the chimney crown likely also has problems. This is the top through which the flue pass- es. As with the mortar, chip away the bad crown spots and fill them with compound. Finish by coating the entire crown with a thin layer of compound. Special com- pounds which cure below freezing temper- atures are available for winter application. While up there, check the condition of the metal flashing between the chimney and the roof. Unless it is severely rusted which requires replacement, coat the joints with flashing compound and paint the flashing. Dear Jim: I added a room to my house. It is efficient with thick batt attic insulation and some extra is left over. Is it important to have the same insulation level in the attic over the existing rooms too? — Gary M. Dear Gary: It is not critical to have the same insulation across the entire attic floor. More insulation is always better though. Even if you cannot cover the entire attic floor over the existing rooms, cover as much of it as you can with the extra. Unfaced batt insulation is best to use for the second layer. If the leftover batt insula- tion has a vapor barrier, cut slits in it with a knife. Otherwise, it can trap moisture between the old and new insulation layers. (Send inquiries to James Dulley, The Free- man, 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit www.dulley.com.) NOVEMBER 2017 HOME 3 JAMES DULLEY Start with a pro when it comes to chimneys SaverSystems This illustration shows the common problems with masonry chimneys. SaverSystems This patch system repairs and seals the flashing around the base of the chimney. A piece of mesh is covered with a tough polymer material that adheres well.

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