chimneys Archives - Page 3 of 4 - Charles Buell Consulting LLC

October 15, 2012 by Charles Buell

The hidden costs of burning wood

It is wood burning season around the country once again!

One of the spin-offs from the energy “crisis” of the 70’s was an increased interest in wood burning stoves and fireplace inserts. Wood burning stove companies, like Vermont Castings and Jotul, were literally resurrected from the terminal disease of disinterest. Efficiencies were greatly improved—-including reductions in pollution emissions, making the units even more

attractive. It also fit in with many people’s interest in a return to “basics” and romantic notions of wood burning. Another thing that gave these heating units a push was the advent of factory built insulated metal chimneys. These chimneys allowed for the stoves and fireplaces to be installed just about anywhere because the weight of bulky/expensive masonry chimneys did not have to be factored into the equation.

Some of these chimneys were what are called “triple wall” chimneys in which air brought from out-doors circulates between the layers to keep the outer layer cool enough to be close to wood structures. These chimneys have a stainless steel inner liner with the outer two layers being galvanized steel. These chimneys are vulnerable to the same aging issues associated with any galvanized materials that are exposed to the elements and have a much shorter life expectancy than their more expensive cousins that were constructed (usually) of two stainless steel layers and the space between was filled with insulating materials—-originally asbestos.

Both of these types of pipes had very specific installation requirements. Proper clearances to combustibles needed to be created and maintained. It is common for problems to occur when these clearances are not maintained and the surface of the pipe is allowed to overheat.

As a builder I had a very real and very scary “learning moment” of my own regarding what can happen if these clearances are not maintained. Often this pipe is run in chases within the walls of the interior of the home until it exits through the roof. Baffles in the attic are installed to prevent insulation from coming in contact with the pipe. Care has to be taken to keep debris and insulation from getting into the baffle space as well as into the space around the pipe where it is concealed inside the wall.

One day as I left the job site and headed off to the lumber yard to get materials, I looked in my rear view mirror to see black smoke billowing out of the soffit vents above the clerestory windows—-kind of like what the oven looks like when turkey catches on fire. It did not take a rocket scientist to know what had happened. Somehow there had been a breach of the enclosure around the pipe and the chase had filled up with blown-in cellulose fiber insulation.

My workers thought I had a usual screw loose as I came roaring into the house and up the stairs. At the base of the chimney chase, the drywall was too hot to touch and the drywall screws were melting the paint. Whoops. Fortunately there was no actual “fire” in the sense of flames. The cellulose fiber, while being the unwitting accomplice in the problem, was doing a good job of containing the smoldering and preventing the whole chase from going up in flames—-which in all likelihood would have destroyed the home. After we tore off the drywall, it was a fairly simple matter to remove the smoldering insulation and hose down the charred framing of the chase. Several of the studs were completely turned to charcoal at the base of the wall. This was the closest I ever came to losing a house during construction. (I had another one where I could not get to the house for a month because the area was off limits due to a raging forest fire—but that is another story.)

The event has made me very pro-active when it comes to evaluating homes that have this type of chimney installed. Many of them can not be inspected at all due to being concealed in chases. As these chimneys age, it behooves anyone buying a home with a metal chimney (or any kind of solid fuel chimney for that mater) to have them carefully and invasively inspected by a qualified chimney sweep.

Take a look at the cap on this 1981 metal chimney.

It is difficult to see in the picture, but the spark arrestor/vermin screen is badly deteriorated and there are obvious holes through the top of the cap. At the very least this cap will need to be replaced. This next picture was taken looking up through the chimney from the fireplace. All those white spots are holes through the cap.

Holes visible in the cap looking up the chimney

I often have buyers ask me, “So, how does the inside of the chimney look?” I think you can see from this picture why that question is very difficult to answer within the context of a home inspection and why having the chimney professionally cleaned and evaluated is important. It is impossible to tell much of anything about this flue other than it needs cleaning, there are holes in the cap, and there are no birds or bees nests in the pipe.

This next picture shows a pipe connection visible in the attic that did not get put back together properly when the roof was replaced. Discoloration from where smoke has entered the attic at the gap is obvious. At least this connection was visible in the attic. It would not be so visible inside a chase.

Damaged metal chimney — damaged metal chimney

One solution to a lot of these aging installations is to convert the chimneys to gas fired stoves and fireplaces. Here is a picture of a chimney that has been re-lined and capped for a new gas fireplace insert.

Crude but hopefully effective—–all of that caulking will at the very least need considerable maintenance—-or perhaps a more appropriate adapter to the smaller pipe liner would be a better long term solution. Removing the original chimney below the roof line would be a better solution and let the new vent come through the roof on its own—-but this would require some patching of the roof.

So as this heating season begins—do you know the condition of your chimney and stove installations?

Charles Buell, Real Estate Inspections in Seattle.

September 5, 2012 by Charles Buell

Real life Jenga

I used to love playing Jenga with my kids—it is a great game that requires skill, patience, planning and an “appreciation” of gravity. One wrong move and the whole thing could collapse.

Over the years I have seen a lot of chimneys. In fact a chimney almost got me fired back in 1970 when I was working part time for one of my college professors. This was all way before I could have ever imagined ending up being a Seattle Home Inspector some 39 years later.

I spent weekends and breaks doing handyman work for him while his house was being remodeled. I ended up working for my professor’s builder for about a year after he fired the guy he had working for him at the time.

While the following incident is not what got the helper fired, I am sure it did not help his case any. The builder sent him up on the roof to start shingling the roof. The roof had been covered with felt paper the day before. We could here the dull thud of “occasional” nails being driven—-until the builder couldn’t stand it any longer and he went up on the roof to see what kind of “progress” the helper was making.

The helper was shingling the roof from the top down!

When questioned about this “less than conventional” approach to installing shingles, the helper merely stated, “This the way I always do it.”

After this event—-and some other events that ultimately got the helper fired, I figured this was my chance to ask the builder for a job. I figured I could EASILY do better than this helper.

The next day—-or soon thereafter—-the builder sent me up on an older part of the roof to tear down the chimney. Seemed simple enough, and even sounded like fun. So, there I was up on the roof and knocking the bricks apart and throwing them two stories down onto the lawn—-having a ton of fun trying to hit the bricks that were already embedded in the grass below. It was not long before I had a growing pile of bricks and a boss running and screaming out of the house like he had pulled up his trousers with a hornet’s nest in them. He was waving his hat—-his bald red head glistening in the sun—-saying things I really can’t repeat here. He wanted to know what the “H” “E” double hockey sticks I thought I was doing. After he calmed down a bit, he informed me that he meant the OTHER chimney. “Oh,” I said.

He didn’t fire me—and the rest of the story—-is my whole life.

Like I said at the start of this post—-over the years, I have seen a lot of chimneys.

The chimney pictured above is perhaps the worst chimney I have ever seen. And I am sure that left to its own devices it will soon find its way to the lawn below, “That is the way they always do it.”

Jenga anyone?

By Charles Buell, Real Estate Inspections in Seattle

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July 23, 2011 by Charles Buell

Chimney mortar joints

Sooner or later all brick chimneys need to be tuck pointed. Tuck pointing refers to the repairs done to the mortar joints when they have to be repaired. This is especially true of older homes where the mortar itself might not have been very good, and where age and missing hats has taken their toll on the chimney from the inside-out.

Chimneys actually fair quite well from normal weather conditions. But, leave the chimney caps off so that water can get into the structure, deterioration can happen more quickly. Add to this, improper venting of gas and oil appliances and deterioration is a sure thing.

Sometimes the whole chimney needs to be tuck-pointed. Other times just doing portions of the chimney is enough—-like the portion above the roof perhaps. Some times it is just the portion near the ground that is in poor condition. If the joints easily scrape away with a pocket knife repairs are warranted. If the mortar is completely missing, repairs are obviously necessary, as in the picture below. In this case the mortar is not only easily scraped away by a pocket knife, the knife actually fits in the joint where the mortar is no longer present.

Deterioration of this chimney was such that some of the bricks needed to be replaced—along with proper tuck-pointing.

Sometimes I am able to get close to the chimney on the roof, but I am not able to see down the flues. I can usually reach my camera up over the top and snap pictures of the condition of the inside of the flues. In this case the camera was able to see that bricks were falling inside the chimney where they may have already damaged, or will damage, the gas furnace metal liner. These metal furnace liners are difficult to assess by the home inspector. There really isn’t an easy way to know whether a brick has fallen inside the flue and ripped a hole in the liner or not. When we see a brick leaning against the liner as in this next picture (and ready to fall) we do have to wonder though if one hasn’t already fallen, and have to recommend that continuity of the liner be verified by the heating contractor.

If, in the Winter, we can see the furnace exhaust coming out of the chimney around the outside of the metal vent—-sometimes even out though the missing mortar joints—-instead of coming out of the cap—-it is a pretty good indication that the liner is not continuous. Maintaining brick chimneys can be expensive but not nearly as expensive as replacement.

***

Charles Buell, Seattle Home Inspector

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