Need Chimney Experts Opinion

SMITTY wrote:I can guarantee it will be cheaper to build that stone cap ...

Now, does anyone know if it's better to have the 2 open ends facing INTO the prevailing wind direction, or perpendicular to it? Or am I not seeing the other 2 ends being open?

The other ends are indeed open... In some cases though they are closed and the opened ends would face the prevailing wind direction and sometimes the open face would run parralel to a valley area or if your on the side of a hill/mountain, etc.

Stainless liner would be the first thing I'd get rid of. Second get rid of the caps. The steel caps rust causing those stains AND anything in the flue gas such as creosote from wood or iron flyash from coal will collect on the crown and the caps thus washing down the sides of the stack with rain. If you feel that you absolutely just have to have some form of cap on your stack, go with a stone/masonry cap as others have suggested. When I build a chimney, I don't use ANY cap.

Den034071 wrote:Im a mason 41 years .Cap is probably not stainless thats causing rust .Den034071 jack

53 years here and I concur

Berlin wrote:Stainless liner would be the first thing I'd get rid of. Second get rid of the caps. The steel caps rust causing those stains AND anything in the flue gas such as creosote from wood or iron flyash from coal will collect on the crown and the caps thus washing down the sides of the stack with rain. If you feel that you absolutely just have to have some form of cap on your stack, go with a stone/masonry cap as others have suggested. When I build a chimney, I don't use ANY cap.

well... nothing ive seen beats a Terra Cotta flu (though no fireplace shop will admit that because seemingly the whole country is on some kind of crusade to sell stainless liners for crazy money (they even have home inspectors and building officials thinking this way) Ive seen a tarra cotta last 100 years+++ and the only damage I ever see is caused by ice build up in a joint (something that will never happen if your burning coal through the winter OR have a nice stone cap made for it). stainless on the other hand ive seen do some seriously funky stuff when mixed with conflicting metals, gases, water, air, soot, etc. and you would think stainless steel would be able to take anything (that is not the case because in the wrong environment the stuff will disintegrate before your very eyes)

When some kid half my age at a fireplace shop told me..."sir, your tarra cotta flu needs to be lined in stainless today, your way is outdated and illegal" ... I told him "your crazy and in 10 years when that stainless rots or turns white/purple and disintegrates from electrolysis he can re-build my flu in solid bronze right"?

As I said...when building or planning your cap give yourself plenty of space between the top of flu and bottom of cap (hell make it 16" if you want), if your doing a stone cap your going to be covering the entiire top area of the chimney (not just the flu itself) so you could be 2' over and it will still stop most any the rain from getting in and this will better prevent "wash down" of soot.

To cap or not cap? I'm sure the chimney likes being uncapped better. But I've seen too many birds, squirrels, racoons, leaves, etc. get in chimneys. With a gas appliance partially blocking them causes poor draft and flue gases to spill out the draft hood or combustion chambers of water heaters, furnaces and boilers. Lots of older equipment out there still that does not have a spill switch in the draft hood. That's a recipe for CO and bad outcomes. Also keeping water out of a chimney is a good thing.
This is what happnes when critters get in a chimney. As far as adding a stainless steel liner, it depends. I agree terra cotta should outlast us all. The reason(s) home inspectors recommend adding liners are these. In my area there is plenty of housing stock that was built in the 1800's and early 1900's. The mortar was a sand and limestone mixture, not a portland type. It turns back to sand and falls out leaving voids in the joints of unlined chimneys. That's just totally unacceptable. Must be relined as the majority of most chimneys are concealed in the walls and not accessible to repoint.

Another common reason home inspectors recommend a liner, even in a perfectly good terra cotta chimney is the installation of a high efficiency furnace that uses pvc pipe and vents out the wall. That often leaves a 3"gas water heater vent in a large terra cotta flue all by itself. It cannot establish a proper draft. The flue gases enter the chimney where they rapidly expand and cool as they try to rise. That causes the gases to condense and that condensate is highly corrosive. It's called an orphaned water heater. Google it. A liner is a must.

Now I've seen chimney sweeps recommend adding a liner in terra cotta chimneys many times when I didn't feel it was necessary. Many of these guys have the video cameras to inspect chimneys which is nice but they are looking for a crack in order to comdemn the chimney and make a bunch of money. I know the NFPA says that they should be relined but in most cases I don't think it is needed

coalkirk wrote:Many of these guys have the video comeras to inspect chimneys which is nice but they are looking for a crack in order to comdemn the chimney and make a bunch of money.

Yep that happened to me 18 years ago. I never bought a liner though. I only run a wood pellet stove in that flue. The other flue is my coal furnace.

I hear the most problems about draft because of UN-insulated or poorly installed liners. If they are put in they need to be insulated and the T joint has to be sealed properly. If you need a liner I tell people to go with the cast in place liners or have a new chimney built instead. They will save money in the short run. I hate liners for coal.

Flyer5 wrote:I hear the most problems about draft because of UN-insulated or poorly installed liners. If they are put in they need to be insulated and the T joint has to be sealed properly. If you need a liner I tell people to go with the cast in place liners or have a new chimney built instead. They will save money in the short run. I hate liners for coal.

I was in a house last week that had a fire from an improperly installed stainless steel liner. Burned the family room, garage and master bedroom. I don't know what the exact defect was but the cause was ruled as improperly installed liner.

The cast in place liners are really nice. They are round and very smooth.

I have a chimney cap with coal and no rusting - its stainless steel.

Dcrane, I really like that stone cap idea (stone with a piece of slate) but my concern would be critters getting down into my chimney. At least with a cap nothing can get in....though I have few trees around the house I think a bird can still build a nest.....

PRengert wrote:I have a chimney cap with coal and no rusting - its stainless steel.

Give it a few years. It will - I guarantee it.

Cover your chimney pipe when you're not burning

jrn8265 wrote:Dcrane, I really like that stone cap idea (stone with a piece of slate) but my concern would be critters getting down into my chimney. At least with a cap nothing can get in....though I have few trees around the house I think a bird can still build a nest.....

SMITTY wrote:

PRengert wrote:I have a chimney cap with coal and no rusting - its stainless steel.

Give it a few years. It will - I guarantee it.

Obviously not the normal performance seen with SS, this one was installed in 1993.....
edit to add second pic which I thought I included the first time...the screen was not SS and rotted away.

jrn8265 wrote:Dcrane, I really like that stone cap idea (stone with a piece of slate) but my concern would be critters getting down into my chimney. At least with a cap nothing can get in....though I have few trees around the house I think a bird can still build a nest.....

You can simply install stainless screen (they even make bronze screening for marine use if you like that old world greening effect like me), the screen is secured inside the edges of the stone/slat yet outside the flu exits. You can use mason equip to secure or do like ive done before and use snips to cut this stuff and leave a "diamond" protruding at each end (top and bottom), 5 inch grinder with a cutting disk makes the indents and I used west system because I had no mortar at the time but whatever... either will hold that screen in place for a lifetime.

Just get rid of the cap entirely. No critters want to live in a chimney with coal smoke going through it...check it in the fall before you light up.