Double flue down draft - Contractor Talk - Professional Construction and Remodeling Forum

ELM · 10-26-2008, 06:15 PM

I am getting a down draft into the basement fireplace when I burn upstairs. Should I extend the offending flue or cap off the basement flue or both.
Does anyone make a damper I can put on the basement flue? Even if I had to go on the roof every time I wanted to open it, that would be better than smoke. I don't burn in the basement that much.
Figured I'd duct tape the basement flue to make sure the problem isn't internal ofcourse.
Suggestions are much appreciated as masonry is not my trade.

raskolnikov · 10-26-2008, 06:35 PM

ELM,
Can you petition the two flues at the top of the stack? Many times this is the simplest way of dealing with this problem.

D.

wazez · 10-26-2008, 07:04 PM

You could try plugging the damper in the fireplace with fiberglass insulation or a tight fitting piece of styrofoam. Not only should this stop your downdraft it will keep warm air from escaping up your chimney.

Tscarborough · 10-27-2008, 10:30 AM

Top of flue dampers are available and easy to install. They open and close from inside the fireplace.

Michael Olding · 10-27-2008, 01:00 PM

You may try introducing some fresh air into the room where your fireplace is operating either by cracking a window or opening your outside air intakes in the fireplace.

This happens frequently in tightly built homes.

eekie34 · 10-27-2008, 07:08 PM

You do need make up air in the house. this is the reason why the smoke is being sucked back down as the house is trying to repressure itself. You can also get a flue stretcher.

batticdoor · 10-27-2008, 07:17 PM

Approximately 100 million homes in North America are constructed with wood or gas burning fireplaces. Unfortunately there are negative side effects that the fireplace brings to a home especially during the winter home-heating season. Fireplaces are energy losers.

Researchers have studied this to determine the amount of heat loss through a fireplace, and the results are amazing. One research study showed that an open damper on an unused fireplace in a well-insulated house can raise overall heating-energy consumption by 30 percent.

A recent study showed that for many consumers, their heating bills may be more than $500 higher per winter due to the air leakage and wasted energy caused by fireplaces.

Why does a home with a fireplace have higher heating bills? Hot air rises. Your heated air leaks out any exit it can find, and when warm heated air is drawn out of your home, cold outside air is drawn in to make up for it. The fireplace is like a giant straw sucking the heated air from your house.

An easy, low-cost solution to this problem is to add a fireplace draftstopper. Available from Battic Door, a company known for their energy conservation products, a fireplace draftstopper is an inflatable pillow that seals the damper, eliminating any air leaks. The pillow is removed whenever the fireplace is used, then reinserted after.

Mark D. Tyrol is a Professional Engineer specializing in cause and origin of construction defects. He developed several residential energy conservation products including an attic stair cover, an attic access door, and is the U.S. distributor of the fireplace draftstopper. To learn more visit our website, batticdoor

stacker · 10-27-2008, 07:28 PM

looks like something made to sell.ron popell will be selling those by the millions,not for 69.95,not for 59.95.not even for 39.95..................

Tscarborough · 10-27-2008, 07:59 PM

Top of flue damper seal tightly, and easy to install, and are not expensive. Plus they are not dog**** ugly like that thing.

wazez · 10-27-2008, 07:59 PM

Looks like an excellent idea to me.

wazez · 10-27-2008, 08:21 PM

Got a question eekie, is a flue stretcher anything like a block stretcher?

raskolnikov · 10-27-2008, 08:45 PM

Tscarborough,
Dog****ugly would be what, the fireplace plug or the fireplace?

D.

Tscarborough · 10-27-2008, 09:34 PM

How about everything in the photo.

jvcstone · 10-28-2008, 11:24 AM

I've used the chimney top dampers many times--I mostly build Rumford fireplaces, constructing my own throat, smoke shelf, smoke chamber and flue. The top damper serves multiple functions--all good. (Lymance?? is the brand name I think)
One thing with multiple flues in the same chase--the flue tops need to be at different heights if down drafting of smoke is to be prevented.

JVC

raskolnikov · 10-28-2008, 03:15 PM

jvcstone,
You're talking inches to stop a downdraft!??? As big as the chimney may be I still find this a wee bit off. We all know that you can build the same fireplace chimney on the same house and plop it all around, on top of a hill, under a hill, with a big old oak on the west side and they'll all burn a bit different. Like Tcsarborough says, "It aint rocket science..." 'cept one needs to be aware of the space the house is filling. The reverse can be applied also, when everything goes against the norm and one is left scratching their heads. Maybe this is one of those times and the chimney top damper is the answer!

D.

ELM · 10-28-2008, 06:17 PM

I removed the rain cap and took some furnace tape and taped off the top of the flue. Air tight as I could ever imagine . Put the rain cap back on and lit the fire. It did not help. I can take a flashlight downstairs and shine it into the fireplace and see smoke billowing down through the damper in the beam of light.
Smokes up the whole downstairs and some of the upstairs. Previous owner used the upstairs place for 24 years with no smoke but he did add rain caps before the sale for asthetics. He did not burn much after the caps were installed. That is the only variable but does not explain the taped flue. This chimney is a real beast and I cannot imagine a cracked flue liner or some internal problem.
???

CJKarl · 10-28-2008, 06:37 PM

Quote:

Originally Posted by ELM

I removed the rain cap and took some furnace tape and taped off the top of the flue. Air tight as I could ever imagine . Put the rain cap back on and lit the fire. It did not help. I can take a flashlight downstairs and shine it into the fireplace and see smoke billowing down through the damper in the beam of light.
Smokes up the whole downstairs and some of the upstairs. Previous owner used the upstairs place for 24 years with no smoke but he did add rain caps before the sale for asthetics. He did not burn much after the caps were installed. That is the only variable but does not explain the taped flue. This chimney is a real beast and I cannot imagine a cracked flue liner or some internal problem.
???

Then I would say the flues are not separated by a wyth inside the chimney. The only way you are going to help the problem is get as much raw air into the fireplace as you can...say as...much in as is going up.

Tscarborough · 10-28-2008, 06:48 PM

If you covered the top of the flue and had smoke transfer then you have larger issues. My guess, sight unseen, would be missing mortar joining the flues in the stack with no masonry separation between flues.