This is not at all necessary and (especially if the cores of cored brick isn't showing) doesn't really achieve much. additionally, it's grandfathered provided it was built to code at the time. If you had to constantly change things in your home to current code, you would spend tens of thousands every year.

Thanks, I looked up there and their isn't any of the cores showing.

The parging has little to do with heat transferring to framing, that concern has more to do with the thickness of the masonry around the smoke chamber and the clearances between the masonry and wood structure.

The parging requirement is primarily to achieve two things; better, less turbulent flow to prevent room smoking and keep a better draft (doesn't really have any effect), and to prevent cored brick, mortar joints and the rough, unparged surface from collecting excessive soot/ creosote in an effort to reduce the likelyhood of chimney fires. A fireplace that's used occasionally and swept every few years won't create a chimney fire hazard in the first place, so neither of these are very significant issues.

Thanks for the good info.

We're located in the NY Metro area and just had our 1920's era wood burning fireplace/chimney cleaned. The sweep mentioned that there are a couple of small cracks in the smoke chamber and that at some point down the road he would recommend considering the smoke tite system, which I'm assuming is a type of parging? They quoted $950.

ALOT OF MISINFORMATION HERE, FIRST OFF THERE IS NO "GRANDFATHERING CLAUSE" WITH POTENTIAL HAZARDS DEALING WITH FIRE CODES.....ALL SMOKE CHAMBERS MUST BE FREE OF ANY CRACKS, HOLES AND MUST MAINTAIN A SMOOTH TRANSITION TO THE FLUE TILES. BECAUSE OVER 80% OF CHIMNEY FIRES OCCUR IN THIS AREA , REGARDLESS OF AGE OF HOME, THIS AREA MUST BE PARGED SMOOTH WITH REFRACTORY MORTAR.

AS FOR PRICING, IT DEPENDS ONTHE DIFFICULTY AND METHOD OF PARGING. IT CAN TAKE ONE DAY OR A FEW DAYS TO PERFORM.....

PARGING A SMOKE CHAMBER HAS TO DO WITH ENSURING THE TRANSFERRING BY-PRODUCTS OF COMBUSTION EASILY TO FLUE TILES WITHOUT INTERFERENCE FROM AREAS THAT MAY INHIBIT FLOW AND ACCUMULATE CREOSOTE SUCH AS CORBELLED BRICKS OR JAGGED EDGES.

THE WALLS OF SMOKE CHAMBER ARE REQUIRED TO BE AT LEAST 8 INCHES THICK OF SOLID MASONRY AND PARGED SMOOTH WITH REFRACTORY MORTAR BY CODE.

REFER TO INTERNATIONAL RESIDENTIAL CODE= IRC/R1001