Restoring Fireplaces From Historic New England

Mantle and firebox from den in August 2010

Last week I shared part one of my query received back from Historic New England regarding preservation for my home. I’ve been a bit confused how to properly preserve and renovate my chimneys and fireboxes. It’s something that’s become a bone of contention—weather we should use stainless liners, thermocrete or nothing. I wanted to hear from the experts and get a preservation’s perspective.

We have four flues and three fireplaces that are exposed and one behind a wall. On the second floor of the house I would love to get two of the fireplaces working again. The den the room we’ve been working on for years now is my biggest priority. The second room will become a bedroom and I’m not as committed to having a functioning fireplace but the mortar in the firebox does need some work. Below tips from the experts as well as photos of each of our fireplaces.

Historic New England: Making old fireplaces functional is usually a matter of selecting which individual fireplaces are most desirable for active use since it is inadvisable from a safety and preservation perspective, and often cost prohibitive as well, to restore every flue and fireplace in a old or historic house to full operability. Regular use of fireplaces in an old chimney can stress the historic masonry and create opportunities for a fire. The safest approach involves adding a flue liner to the fireplaces that will be used and capping and/or sealing off the others.

Historic New England recommends use of a stainless steel “floating” liner in historic chimneys as floating liners do not alter or damage historic chimney masonry. A poured-in-place liner essentially replaces the historic chimney structure with a new solid masonry structure in which the old chimney is made redundant. While the poured in place liner is perfectly acceptable as a means of making an old chimney functional, the lining cannot be removed at a later date and thus violates the first principle of architectural conservation, that whatever modifications are made to an historic structure ought to be reversible without damaging or destroying the historic fabric of the building. Exceptions might be made to install a poured in place liner, for example, in a flue used for a heating system, which receives heavy use and requires a higher safety standard, or for a more recent or modern chimney, but if possible, introducing a poured in place liner into an old or historic chimney should be avoided.

Among the possible downside risks to the poured-in-place liner is the potential for the lining slurry to create pressure on or burst through a weak point in the masonry. The downsides of the floating stainless steel liner are 1) the need for a relatively straight shot for the steel liner (which cannot accommodate a significant angle in the flue) to run from the flue opening to the firebox and 2) the limited life span of the stainless material. These considerations may affect or limit the fireboxes selected for lining.

Within the fireplace opening, selective replacement of deteriorated brick may be necessary. A restoration mason should be able to replace individual brick in the firebox itself and repoint in an appropriate mortar. Traditionally, protected sections of 18th century chimneys were laid up using clay mortar, but the fireboxes and the exposed sections of the chimney at and above the roofline used a lime mortar as the lime mortar was more durable and weatherproof than clay. Care should be exercised not to introduce a modern Portland cement mortar into a historic masonry structure as the modern mortar will be stronger than the historic brick and cause cracking and deterioration. A high lime mortar, with very little cement and a high proportion of sand, is typical of historic lime mortars: one part cement, 4 parts lime and 12-15 parts sand may be used as a guideline. In historic masonry, the mortar is considered a “sacrificial” material, intended to give way, to flex within the structure, to absorb and release moisture from within the structure, and periodically to be replaced by digging out the old mortar and pointing with new.

Traditionally, the area around the fireplace opening inside the mantel, would have been parged, or coated, with a lime plaster, and then painted/stained black. Only high-style houses would have had tiled fireplace surrounds in the 18th century and many of those now present on older houses were likely to have been installed in the late 19th or early 20th century.

For more detailed information on the construction of fireplaces and brick manufacture, see A Building History of Northern New England, James L. Garvin, published by University Press of New England. Also useful is “Chimneys and Flues” by Russell Taylor:
For more detailed information on traditional mortars, see “Repointing Mortar Joints in Historic Masonry Buildings,” National Park Service Preservation Brief #2 available on the NPS website at

Capping unused flues at the roofline without a highly visible chimney cap may require a custom solution. Pop-up dampers, such as the “Chim-a-Lator” at Volko Supply, may have a sufficiently low profile (if painted black) not to obtrusive visually. If the chimney is not to be used at all, a bluestone cap can be mortared in over the chimney opening. Chimney “balloons” are available to place inside an unused flue but you can also fashion your own “balloon” using a “pillow” fashioned from house wrap (Tyvek, for example) stuffed with loose fill fiberglass insulation and stapled and duct taped at the seams. Extra caution must be taken, however, not to place anything in a chimney or flue that may be subject to heating or cross-over sparks from an adjacent flue.

On the second floor in the bedroom. The shelf is not original and needs to be removed. I don’t need to having a working fireplace in this room but it would be nice to light in the winter.

First floor in the front part of the house. A heating system was being vented through this flue.

First floor in the back of the house. We think we have a fireplace behind this wall. This room will become our kitchen and dining room. Would be fun to have a working fireplace.

Related Posts:
Historic Interior Shutters from Historic New England
Learning More About Chimneys
Day 3: Brick Chimney Rebuild

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  1. Yes I will go we’re the job takes us. Sorrry so late on the response Joan, Connecticut love to see you chimney and fireplace call or email Matt at 978 994 7171 or colonialbrickworks @ thanks Matt


  2. I have a 1799 cape in northwestern CT. I am not skilled enough to do this myself. Do you venture to Connecticut at all?


  3. Im am a restoration mason and fix old fire places. Using the right materials is key. Fixing it can be involved, but that depends on how worne it is. Contact me if you would like me to look at it and give an estaminet.


  4. I totally agree with you Renee. Fireplaces are inefficient. But I’m not going to use them everyday and it’s kinda nice in the dead of winter to light a fire. It’s part of the allure of an old home.

    On our first floor we have a fireplace that currently is being vented with a furnace. I’m contemplating putting a wood burning stove in which will warm the entire.


  5. Wellllll, yes, a real fireplace in the bedroom is romantic BUT it’s no joke hauling wood upstairs and ashes downstairs and no, they do not heat a room with any efficiency. It’s better than nothing but so much heat goes up the chimmney that it won’t save $$$ over modern day heat. That’s why we call it progress LOL I lived with wood heat back in the day when I was playing hippie and I can tell you, it’s dirty. If you’re going to have white curtains or have white duvets, trust me, they’re going to need frequent cleaning if you use the fireplace much. Unless you want to register your home as some sort of historic building, I’d put a nice gas fireplace in the bedrooms. They put out some heat!!


  6. I hope, hope you can restore the one you think you’ve got in the kitchen/dining room. We have one and it’s truly fantastic in the fall and winter. I think you would love it!

    We have 3 working fireplaces, 2 of which we use. We knew there was one in our living room and broke into the wall to see it, but it was in such bad shape that we covered it right back up. They are all Rumford fireplaces and are big enough for just a Duraflame, which bums my husband out because he loves to get a big, roaring fire going.

    Awesome info as always, Katy!


  7. While I understand Historic New England’s take on the chimneys, we used a poured in place process on our 1784 house in Connecticut and it has been amazing. Not only were we able to restore functionality to all four fireplaces on our central chimney, but it also greatly stabilized the chimmey structure and eliminated a very major fire and carbon monoxide concern. I’m generally as by the book as they come in terms of restoration, but this is one area where I feel that the cost of being unable to remove the change is far outweighed by the benefits. I say go for the poured flues and enjoy your fireplaces. Usable fireplaces contribute significantly to the character of the home, are authentic and are a value-added detail that will help to ensure the long-term appeal and survivability do the house.