Is this a more modern era fireplace?
In fireplace construction, first there is a core built.
This core contains the area where you build your fire, forms the throat where the damper is located and then the flue which is how the smoke exits.
This core is then surrounded with concrete block.
The concrete block is then "faced" with brick or stone in the areas where you see the structure.
In the attic or between the walls you there wouldn't be a need for the decorative facing.
If you have smoke leaking through all this masonry then there must be a compromise in the core.
Very new type chimney/fireplace construction may eliminate the concrete block stage and the core can be faced directly with a UL listed product such as Isokern.
Very old chimney / fireplace construction may have used a brick core.
If some of these bricks failed, smoke could find its way out in a way other than up the chimney.
In whatever case, you need to get an experienced mason to check things out right away as there is the definate possibility of a fire starting in an unseen location in your home!
Sparks from your fire are following the draft which is not all going up your chimney.
I am not a mason, but have a friend who is and I have helped him on quite a few jobs over the years as I find it interesting.

Oh Westernmainer,
Thanks so much for that long reply......but I guess I didn't explain myself well enough. I'm talking about water leaking. The fieldstone seems to act like sponges outside and when it rains, the water just runs down into the fieldstone covering the fireplace in the living room.
For it to not leak, we have to apply waterproofing stuff to the outside fieldstone almost every year. Thanks again for your long reply.
It actually did answer another question I had, but didn't ask yet!

In that case, it must be the flashing or lead skirt is to blame.
The flashing is like an umbrella that covers the seam between the roofing material and the chimney material.
If your home is new, then there is the chance that your house actually shrunk as it dried out which can leave a gap where the chimney penetrates the roof.
One house that we built actually shrunk an inch and left a gap big enough so that snow swirled in!
This is a much easier "fix" than if it were smoke!
But again, a mason is the one to come and look at it.
A few taps on the flashing may be all that it takes or it may need to be replaced.
Not really a job for the home owner due to it being up on the roof and the fact that the lead flashing can have a tendancy to tear and it is easy to try and overdo the rebending of it.

Thanks for your help westernmainer! :)

Yup, like a sieve. Leaks smoke along it's entire length too.
Ours is old and solid New England field stone. We have a stepped area that holds water when it rains and it just leaks in.

We are going to get a new liner and have it repointed and weather sealed. The stepped slope will be made slanted to shed water, not hold it.

And a new damper/cap. Lots to do, and no one is returning our calls, so we will be out the fireplace this season:(

Bummer, wianno! Sounds like it needs a drastic "makeover"!
How do they put a new liner in an older fireplace? Will the liner be made out of tiles? I guess they could make the liner, and then lower down into the chimney.
We have a second fireplace that lost a tile, when my husband was pulling out the woodstove metal flue liner. I just thought they had to put the tiles in one at a time, and couldn't figure out how they worked in that little space!

We have to waterproof our outside fieldstone almost every year, or the water seems to run like a river down the stone in the living room.

Good luck with all you have to do!

A replacement liner is most often stainless steel - the only way to replace the entire flue with clay tiles is to rebuild the chimney. Normally, with an open faced fireplace the existing flue tiles will be removed and the stainless liner will replace those.

How do they remove all the tiles? It's unfortunate that we lost that 1 tile. But I suppose a stainless steel liner would be safer....since there would be no grouting to come out.

There are other ways to put in ceramic liners. They drop a bladder in the flue and inflate it, then pour in the ceramic material (like cement), which hardens. Its expensive, like 3-5k. We recieved a quote for 9k, but that was a phishing attempt. I think we will go insulated stainless sleeves, however.

yup, wianno is correct there are other options; the one he mentions is the cast liner, very popular in europe and adds strength to the chimney as well. It was developed for large industrial/commerical boilers/furnaces and within the last decade has become much more cost competative and much more popular in the residential market.

there is a fairly simple and price competative way to install clay flue tiles into existing chimneys; the process includes busting the old damaged flue tile, smoothing the remaining flue, then lowering new tiles in from the top. Fewer people are doing this now that stainless and stainless flex liners have become popular and are easier to install, and less specialized equiptment is required.

catherine T: I was just rereading your post and realize how unfortunate that is to have to have one tile crack, howerver rather than relining by any of the previously mentioned methods i would suggest googling "firesafe industries" they have a process for residential chimneys that fixes all the imperfections, cracks etc, quickly and quite possibly for a much lower price.

The product Berlin mentioned is called FireGuard - it is a great product for correcting eroded mortar joints but is not intended for cracked flues. In addition, in order to install a "poured" or "cast in place" liner, the flue tiles still have to be removed in order to make sure you will maintain the proper flue size.

A person never stands in there to work, do they? I'm thinking it's probably much too small in most chimneys.

The method of repair depends on where your chimney is situated. Of course a large portion of the job is done from the top of your chimney; however if it is a stone chimney on the exterior the normal way to access the lower interior area of your chimney is to remove sections of the firebox and damper assembly as necessary and then re-install the damper assembly and the firebox. That enlarges the area a bit to allow someone to gain access a little more freely. Otherwise the normal way to gain access would be cutting into the firebox area from the exterior of the chimney; but as I said, that isn't normally done with stone chimneys.

Thanks jocelynj!

you're welcome!
As a correction of my previous post, I now realize that I said "the normal way to gain access would be cutting into the firebox area" rather than the firebox I meant smoke chamber area. Sorry for the oops.

Just had this beauty completely redone inside and out, including sealed. It's still leaking from the inside at the top running down the middle of the stones. New roof too......Help!!!