Must I have a chimney?

Question

I have a house where the chimney is falling apart and the estimates to take it down and rebuild are over $2K. I just have a furnace and hot water heater exhausting through it. The gas is off. Is there a reason I must replace the chimney with brick? Isn’t there a cheaper way that still works? I do not care about appearance in this house.

Also I would like to save money by DIY the demolition. As I said there is not exhaust running thorough it now, so do I just go up there with a hammer and start knocking out bricks?

Also I would like to save money by DIY the demolition.  As I said there is not exhaust running thorough it now, so do I just go up there with a hammer and start knocking out bricks?

Daniel Fisher · Answer

There are stainless steel insulated chimneys that people use on the outside. It sits on a small metal platform that is anchored to the wall. It is then stabilized by brackets attached to the wall every so often.
I don't know the cost of this type of chimney.
Another alternative would be using 16x16 chimney blocks with an 8x8 clay flue.

Adam Johnson · Answer

Steve Might - couple ideas for you.  As I replace furnaces, I have been going to 90+ units in preparation for future failing chimneys, even if they are ok at the time of the swap.  If all goes well, the furnace will outlast the chimney on any of my older buildings, so I look ahead with that in mind.  You might consider speaking to your HVAC contractors to see if they will "trade" your current furnace toward a 90+ unit.  I have a small HVAC guy that is a wheeler and dealer, he almost always has used units with useful life left, he goes through them and gives a 1 year warranty on them (if you buy a used one from him), so your newer furnace might have value to somebody else and you might get credit for some of the remaining value of your existing furnace.  You will likely need to dig into your pocket still, but not nearly what the chimney repair will cost and if this is a long-term hold, you have added value.  If it is a mid-term hold, you will still recover/save enough money to make it worth considering, and you will have an added plus of a 90+ furnace when you go to sell.  If it is a flip house, you should run numbers/options to see what is best.

Regarding the water heater, you can switch to a direct vent gas unit, but these are more expensive than simply switching to electric.  If you have enough capacity and if the utilities are paid by the tenant, then the added operating cost of an electric heater really isn't your problem, and a tenant is unlikely to say they don't want to rent because it has electric vs. gas water heat.  If the current water heater is good still, you might be able to save it for another property, sell it on Craigslist, or maybe trade it with somebody for something of value to you.

Throughout our routine maintenance activities, I ALWAYS replace furnaces and water heaters with direct vent or electric units, because I know it is only a matter of time before I have to deal with the chimneys, even if I no longer use them.  Plan ahead!  In your case, I think with a little creativity you can reduce your cost today while also adding future value to the property.

Rob K. · Answer

I have seen metal chimneys on the outside in place of the brick one. The only problem is that once you tear out the bricks, you will have no siding behind there. Something will need to be done with it.

Jon Holdman · Answer

If you're just trying to vent the furnace and water heater, then you only need type-B steel vent pipe.  The sizing is determined by the BTUs of the two appliances.  You can't just run these directly into a chimney, anyway.  The chimney would need a liner and these would connect to the liner.  You could run the B vent up through the roof.  IIRC, that's preferred, but code allows it to go outside then up.  The are specifications for how high it has to go above the surrounding roof.  The B-vent also has to be 1" away from anything combustible.

Stephanie Dupuis · Answer

These guys have already said this - but I'll add.

I've also torn down a brick chimney by myself due to earthquake damage (2001 Nisqually quake). Depending on how high your chimney is (I can't tell form the pics), rent some platforms go at it with 2/3 lb. hammers, metal chisels, etc. Carefully break it away. We were able to cap ours off at the roofline.

But, at one of my properties in town (my investment farm area was at the heart of the earthquake epicenter), my gas water heater vents out the side of my house. A huge metal pipe goes right up the side of the house. Same with the furnace. This is standard practice in our area. HVAC prefers to vent out the side of the house on gas furnaces, as stated, to prevent future issues due to problems caused by failing chimneys (they fall apart here, and we have earthquakes).

I'm amazed you got a quote for $2000 for a chimney rebuilt. Our quote for a similar rebuilt averaged $10,000! I just rebuilt a 3 ft. chimney for $3,000 and the crown is failing - more learning I get to do. : )

Roy N. · Answer

Steve,

Your chimney is completely external!  In my response to your PM, I somehow presumed it passed up through the house ... probably because that's how the chimneys all our 150+yr old houses are in this area.

In this case, pulling down the chimney will be easy and there will be no internal mess or repair.   An insulated/lined stainless steel chimney - as I had suggested for passing through the attic and Daniel indicated above - would be an easy and, probably the cheapest, solution.   Depending on how far the existing chimney footing sits in the ground and where the flu exits the building, you may need to dig a well and put in some drainage (crushed stone) ... but likely not.

Mark Forest · Answer

This chimney is bad from top to bottom.  I do not think we can post pictures here, but I did put his question on DIY chat at

http://www.diychatroom.com/f105/rebuild-chimney-cheaply-182228/

I have posted pictures there.  All are welcome to se what I have been talking about. You can see how the back of house is only about thre feet to the back fence so I do not care how it looks when done.

Dell Schlabach · Answer

We have removed quite a few chimneys, especially when we need to replace furnaces, we use 90+ so they can be direct vented. We swap out the old gas hotwater tank as well and no more need for a chimney, or liners.

If you are a diyer, why not knock out the chimney yourself, buy seconds or discontinued brick, lay the chimney yourself or hire a handyman.... most of the chimneys we needed to rebuild are only the top sectionsfrom the attic through the roof, its rare that the entire chimney is bad.

I had a "through the roof" chimney replacement a few years ago, 1500_2700 quote range. Decided to do it myself, had a kid help me, we cleaned up, reused the same brick and did the project in about six hours for a couple hundred.

Had my hvac guy drop in a liner 150.00 and we were good to go.

Around here we have fireplace shops that do steel chimney installs, may be worth checking into.

Anyplace that sells the type-B steel chimney supplies should be able to get you names of installers.

Mark Forest · Answer

Jon I have seen a house that is just a meatal pipe, but I assumed it was a firepalce or something.  What kind of contractor should I consult?  I am surprised none of the furnace guys I talk to have considered thkis.  A new brick chimney cost a fortune.

Mark Forest · Answer

I should have mentioned that I did look into straight PVC, but I was told by several pros that it has to be a 90% unit for that.  My furnace is new, but it is not 90%, and the same is true of my hot water heater.

I called a couple of furnace companies and they seem stymied by my question.  They just say brick is what is always used, but can't say why.

Must I have a chimney?

Most Popular Reply