Chimney Upkeep

As a home inspector, while inspecting a home, not only I look for defects in the homes, I also advise potential home buyers on how to operate the home’s components, safely and properly. Good maintenance is essential to avoid costly repairs and major accidents.

While a lot has been written up on how to void chimney fires, much of it is on how to build fires, keep it in control and keep the chimney free of creosote. This post does not attempt to address the fireplace design issues in detail. After the foundations, most of the masonry fireplaces are the only other components that are still built in situ. Hence the knowledge and accuracy of the craftsmen is at serious play. In the last 20 years there has been a lot of automation in home building and many components are pre-built offsite and installed in the home. Prefabricated fireplaces are pre-engineered and designed for specific criteria and come with manufacturer’s installation manuals etc. However that is not the case with site built masonry fireplaces. The knowledge and good skills of the masons have a great degree of play, when it comes to building masonry fireplaces. A lot can go wrong such as improper throat design, chamber sizes, height of the chimney etc, any of which can impede a good fire or cause serious back drafting etc.

Such issues can only be checked on site by a competent professional. Assuming that there are no design issues, and the fire place has not been retrofitted, the home owner should stick to the type of fuel that the fireplace has originally been built.

For the most part, the fireplaces built after 1920, in most urban cities are generally not a primary source of heating the home. In many cases, these are an appliance of ambience only, to snuggle around or when you have company. If the damper is not kept closed when the fireplace is not in use it can be a source of loss of heat. Most of the masonry fireplaces do not have a built in glass enclosure, when first delivered by the builder. Such doors are after market devices that are generally installed by the home owners and are highly recommended to check the draft and loss of heat through this venue, when fireplace is not in use. Keep the damper open, is almost like keeping one window open all the time.

It is a good idea to check the damper operation and clean up the ash pit before the onslaught of winter, besides of course have the chimney sweep clean the chimney. To avoid Termite infestation the wood logs should be kept about a foot about the ground. The wood should be hardwood and seasoned for at least one year after cutting. Do not use construction lumber, particularly the treated lumber or plywood etc as these have chemicals impregnated in them, which can emit harmful emissions. Softwoods, or too much of newspapers, or paper logs can also be a source of excessive creosote built up.

Most of the masonry fireplaces do not have a provision for make up air that is essential for efficient burning of the wood. These fireplaces rely on getting the oxygen from the room in which the fireplace is located. If the chimney is extremely cold, it can also impede in the draft which can be a catalyst for the creosote buildup.

Some chimney fires are more critical than others. Small chimney fires often go undetected as these can be limited to within the flue only. Nonetheless if the condition is unchecked for a period of time, the creosote build up can also flare up uncontrollably.

These unwarranted bursts of fires create very high temperatures and can cause damage to the mortar between the tiles and or the bricks etc resulting in cracks etc. This can result in serious condition as the flames can reach the surrounding flammable materials through these cracks etc.

When inspecting the chimneys, one of the things that I look for is a telltale sign if the fireplace or chimney has experienced any spot explosive fire in the past. Bubbled up creosote blobs, long streaks, wrapped metal components, missing bonding mortars, flares of creosote in the vicinity etc all point to a possible chimney fire in the past.

Contrary to the popular belief that only wood burning masonry fireplaces need cleaning, I have seen few prefabricated and many gas burning fireplaces that had serious creosote build up. Prevention, good maintenance and good fire building practices are the key here to prevent any serious issue.

As of this writing, building department in our geographical area, do not require a fire extinguisher in the vicinity of the fireplace. However I think it is a good idea to have a 10 Lbs AB fire extinguisher close-by to the fireplace. Keeping a garden hose ready outside, to cool down the roof, in the event of any fire is also a good preventive measure.

Fireplace is one area that needs an extra measure of scrutiny, not only when you buy the home and have it inspected, but also after each fire building season.

While I do offer an opinion on home inspections if you send me the report by email, and on many components, it is feasible to advice, fireplace / chimney is one area where only an on sight expert can render the opinion. There is no alternative to an experienced home inspector and a good and thorough home inspection.