wrote in message
ups.com...
The other week I had a fire going in my family room fireplace. Shortly
after starting the fire, I noticed the smoke was backing up in the
chimney - and the whole downstairs was quickly flooded with smoke.
This is the second time in a year this has happened. After the 1st
time, we suspected it might be a negative pressure situation, so I have
been sure to crack a nearby window every time I start a fire ... guess
that doesn't help.

It can happen for a couple of reason. One is the temperature differential.
If the fire is just starting, the damper is open, the cold air in the
chimney wants to come down as it is heavier than the air below it. Once the
fire gets going and produces a lot of heat, the air flow can be reversed.
If you feel a cold down draft, try lighting some loosely crumpled newspaper
paper just to get a hot air flow going up. The paper gives a lot of heat
quickly.


He though the smoke backup was probably caused by blowing
winds, and said the caps may help that problem.

He is correct. I've often had back puffs in windy weather and the cops do
help.





The chimney sweep (also a fireman for a local FD) made it sound as if
this was a potentially severe problem, and recommended that I not use
the fireplace until getting it fixed.

Yes, it is. I can't see it so I don't know the severity but fire can geet
into cracks and cause overheating of the surrounding area.


Of course, he had a solution
ready to go: to use some product called "Smoketite" to seal the gaps.
Cost $500.

I hate getting inspections and repairs from the same people, as the
potential for abuse and fraud is too great. Does anyone know if this
truly is a problem or, better yet, if the repair he's suggesting is
worth the $500.

I'm not familiar with the Smoketite so I cannot comment. You have to rely
on the reputation of the inspector in this case. Has he been around a long
time? Locals use him a lot? If he is on the local FD, you can probably ask
around and find out if he is OK to trust.

As for the "worth $500", I know of people that had chimney fires. They would
have paid that much gladly to prevent the fire. Is this particular job
worth that much? I have no idea what is involved.