After searching the site for a while, I had a specific question regarding my open masonry fireplace which we use about once a week. We have experienced smoke puffing out into the room during a hot fire and I suspect the problem could be the arch over the firebox. I’m using oak and walnut that has been cut and stacked for 16 months, so I wouldn’t think its excess water vapor from unseasoned wood making room smoky.
This summer, I had a brick mason rebuild the 3 walls of the firebox due to the age and deterioration. I swept the flue recently and it’s clean to where I can see the orange clay tiles. I have a standard SS flue cap from Lowes mounted on top. We lite a fire a few nights ago, and had some smoke puffing out to the point of seeing grey haze in the room. This happened after the fire had been going for about two hours. I opened the glass on the exterior storm door in the garage and the haze cleared out after a while. The damper was wide open and I had primed the flue with 3 rolled up newspapers like a torch prior to lighting fire. The fireplace is on the basement outside wall and our basement is in two sections. Half is family room where the fireplace is and the other half is one car garage with laundry room area. I usually have the door between the family room and garage slightly open thinking the drafty garage door would supplement the oxygen for the fireplace. We shut the door going upstairs and there are no furnace supply or return ducts in the basement. I have a fireback against the back wall of the firebox and use standard fire grate but with the front two legs propped up on a firebrick to prevent roll out.
To test this theory, I will remove the fireback and place the grate as close to back wall as possible. If problem still persists, I was going to get a piece of stainless steel and cover about 3-4 inches of the arch. I will temporarily mount the SS cover with two C clamps. If this prevented smoke puffing out I would buy a hood or make something more permanent.
Below dimensions of fireplace. What other factors could cause smoke puffing back that I've overlooked?
Chimney height 25’
Flue opening 7”x11”
Fireplace width 35”
Fireplace height – peak of arch is 28” and goes down to 21” on both sides
Backwall Width 28”
Firebox depth 20” – With the fireback I lose 4”
Firebox floor to damper height 36”
Damper Opening 6”x27”
Fireplace hearth and back wall all brick – 10’ wide and from concrete floor to bottom of floor joists.
This summer, I had a brick mason rebuild the 3 walls of the firebox due to the age and deterioration. I swept the flue recently and it’s clean to where I can see the orange clay tiles. I have a standard SS flue cap from Lowes mounted on top. We lite a fire a few nights ago, and had some smoke puffing out to the point of seeing grey haze in the room. This happened after the fire had been going for about two hours. I opened the glass on the exterior storm door in the garage and the haze cleared out after a while. The damper was wide open and I had primed the flue with 3 rolled up newspapers like a torch prior to lighting fire. The fireplace is on the basement outside wall and our basement is in two sections. Half is family room where the fireplace is and the other half is one car garage with laundry room area. I usually have the door between the family room and garage slightly open thinking the drafty garage door would supplement the oxygen for the fireplace. We shut the door going upstairs and there are no furnace supply or return ducts in the basement. I have a fireback against the back wall of the firebox and use standard fire grate but with the front two legs propped up on a firebrick to prevent roll out.
To test this theory, I will remove the fireback and place the grate as close to back wall as possible. If problem still persists, I was going to get a piece of stainless steel and cover about 3-4 inches of the arch. I will temporarily mount the SS cover with two C clamps. If this prevented smoke puffing out I would buy a hood or make something more permanent.
Below dimensions of fireplace. What other factors could cause smoke puffing back that I've overlooked?
Chimney height 25’
Flue opening 7”x11”
Fireplace width 35”
Fireplace height – peak of arch is 28” and goes down to 21” on both sides
Backwall Width 28”
Firebox depth 20” – With the fireback I lose 4”
Firebox floor to damper height 36”
Damper Opening 6”x27”
Fireplace hearth and back wall all brick – 10’ wide and from concrete floor to bottom of floor joists.
