Fireplaces, Heating Stoves, Flues and Chimneys - Fireplace with ash smell

I need some help to see if this is normal and if anything can be done about it.

I recently bought a house with a fireplace, which was cleaned prior to me moving in. However, there was previously an uncontrolled fire in the fireplace/chimney (not sure how that happens, brick fireplace, maybe someone can explain that too). There are now glass doors that close, which I suspect was recently installed. At any rate, despite this, the house occasionally smells like "fireplace" even when I fire has been lit for weeks. It typically occurs after rain but not always.

I figured that the smell is from the "fire damage" to the chimney/fireplace. Is that correct or could it be something else. Any way to prevent it/clean it up?

Thanks much.

Keep damper closed when not using fireplace. Sometimes this is enough to stop the air flow, but some dampers leak air. Make sure fireplace screen fits tight. Check to see if chimney is capped. When rain comes in contact with soot, it tends to smell. They make chimney top dampers that are operated by a chain to prevent the backdrafting of chimney. A fireplace insert with a full stainless chimney liner might also help. There is no 100% sure cure for the backdrafting of chimney. It is a relationship of the chimney with the house and the airflow. Your house has negative air pressure. Air is coming in through the chimney and circulating through the house. Keeping a fresh pan of baking soda in fireplace might help, too.

Houses are built tighter these days. When you exhaust air out of home, for instance, with powerful range exhaust you force air out of house. New air is pulled in through chimney and walls and around windows and doors. Kitchen & bath vents, clothes dryers and central vacuum cleaners can cause similar problems. So, when pressure inside the house becomes negative compared to the outside, air is drawn through chimney and in some cases causes smoke to enter the room if burning the fireplace. This usually occurs when the fire is dying out because draft is weak then.

Some reading material on chimney fires. The second one is a little long but contains more in-depth info:

http://www.hpba.org/consumer/ChimneyFireFacts.shtml
http://www.msue.msu.edu/msue/imp/mod02/01500598.html

thanks much folks. i went back and looked after reading the above posts/links.

the fireplace screen isn't very tight (i think a subpar home installation by the last owner), plus the bottom has a vent that is always open, ie. when it is very cold outside i can ALWAYS feel a cold draft coming into the bottom vent of the fireplace screen. I close the damper and i still get some airflow although not as much.

the chimney has a cover on top of it, but not a second damper if that is what you were referring to for a chimeny damper.

i again have a very strong "fire/ash" smell in my house today, i made a fire 2 days ago and it is damp outside--rain.

i own another house w/ my brother in the same area, and we have a fireplace as well, without a screen--just an open fireplace. we keep the damper always open and rarely if ever have an ash smell. plus, there is no airflow coming from the chimney into the house.

does this mean the house w/ the ash smell is backdrafting all the time causing the smell? is there a way i can prevent this? the house was built in 1981 (other house w/ the open fireplace and no smell built in 1961). i don't run a fan often, the only thing that has been running constantly is the heater. thanks much for your help.

I have a brand new home and glass doors and had the same problem. I first used "fire proof" caulk around all openings between glass door frame. This relulted in much improvement but it still smelled in warmer weather. I noticed there is a slight separation between the two doors. I then ran a pice of tape down the middle of the door and NO SMELL. I would like to know what type of stripping I might use in back of the door so I don't need to remove tape to use the fireplace.