Chimneys Archives - Page 4 of 5 - Charles Buell Consulting LLC

November 19, 2011 by Charles Buell

Undermined footings—the coming collapse

A house’s footings need all the support they can get.

The kind of support I am talking about is the dirt kind. And in this case the footings are for a very tall and heavy chimney. This crawl space has been excavated to create a place for the water heater and the furnace. In the process, the area at the base of the chimney has been excavated vertically leaving the chimney footing vulnerable to undermining and possible collapse.

Undermined footing — Improperly supported footings will result in collapse sooner or later

This 20′ tall chimney weights at least 4-1/2 tons. That amount of weight, coupled with the presence of and/or the lack of moisture in the soil, and/or the odd earthquake, and/or a jet breaking the sound barrier, could result in the chimney ripping down through the house into the crawlspace. While this would most likely do no more than wake the dead, it would be very disconcerting to anyone that might be unlucky enough to be in the crawl space at the time.

In this case, since the furnace needed to be replaced anyway, I recommended that the chimney be removed and that a proper area be constructed for the water heater and the furnace, and to construct walls to properly retain the earthen walls. The buyer had already discussed the desire to gain some space in the kitchen for a proposed remodel, and had shown a desire to install a new high efficiency furnace, so recommending removal of the chimney fit those desires nicely.

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Charles Buell, Seattle Home Inspector

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September 30, 2011 by Charles Buell

Do you know where your fireplace damper is?

I think we all want to save energy—it seems that there are always things we would rather spend our money on. One very frequently overlooked place where a lot of energy—and thus money—gets wasted is up the chimney.

Typical fireplace — Is this your fireplace?

As wind move across the top of the chimney, a negative pressure is created on the chimney causing it to literally suck heat out of the house. Of course even without the wind the chimney will work hard to remove the heat from your home just through the chimney’s natural draft. If you open a window or door, or increase the wind speed, the flow can be dramatically increased. When the damper is completely missing, as it was in the fireplace pictured above, the waste of heat is continual—–you are literally heating the whole outdoors. This picture is looking up inside the fire box to where the damper is supposed to be.

Fireplace with missing damper — The fireplace damper missing or open is all the same

Even with proper dampers in place, this can still be a place where much heat is lost from the home.

Having glass door enclosures installed can help a lot, but remember—-many of these have air intakes at the bottom that provide combustion air to the fireplace. If they are left open when the fireplace is not in use they can still allow heat to be drawn up the chimney.

If you really want to waste a lot of energy (unless it is your only means of heating the home) actually use the fireplace. Fireplaces, during use, without proper glass enclosures, suck tremendous volumes of air from the home. This is why rooms away from the fireplace become so much colder than the room the fireplace is in. While some fireplace designs provide less waste than others, they are no match for more modern methods of heating.

Assuming that in terms of heating our homes we are going to stick with the idea of “central heating” as opposed to “specific location” heating (hot stones and water bottles under the blanket), we are sort of stuck with central heating.

When the kids and I used to go camping at the beach it was always fun to build a fire on the beach and then take one of the hot rocks back to the tent and put it in the end of our sleeping bags. Did you ever notice how when you are camping and you are nice and warm in your sleeping bag and then when you wake up in the morning the inside of the tent is dripping with the condensation created from breathing during the night? The same principle can happen in your home when the whole home isn’t heated evenly.

I would go so far as to say that maintaining uniform temperatures in today’s tighter homes is essential to maintaining a healthy indoor environment.

Is your fireplace damper opened or closed right now?

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Charles Buell, Seattle Home Inspector

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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.

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Charles Buell, Seattle Home Inspector

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