Cosmetic patches on that will not fix what ails it. It supports your house. It needs to be carefully removed. With new supports engineered. It’s a MAJOR structural issue.

In my experience, it would be highly unusual to have a chimney that "supports your house". Chimneys are almost always built on their own footings and are separate from the house foundation. It's hard to see what purpose is served by alarmist assertions like "it supports your house" when it's impossible to tell if this is the case from the photographs provided.

I do think the structural engineer's concern that so much of the chimney cannot be seen is valid. Information from the company that specializes in chimney restoration will be invaluable. Inspection of the interior of the chimney using a camera lowered from the roof ought to provide information about the condition of the chimney parts that are hidden behind walls unless there is/are a liner(s) that prevents seeing the brick at all. Logically, the condition of the bricks and mortar should not be as bad as the cellar photo in areas where moisture was not as much of a problem. 120 years is actually not a remarkably long time for a house. I know of many cases, my own house included, where the masonry chimneys are in good condition after 200+'years. Whatever caused the seriously deterioration of mortar and brick in this house has presumably been corrected, but it is possible that so much of the brick itself needs replacement that removal and rebuilding may be the best option. Trust in the expertise of the specialist you've already contacted. No one can conclude that it is essential to remove it and it's a "MAJOR structural issue" by looking at a single photograph online.

You don’t have experience with dissecting old houses obviously. Even recently as the 70’s, chimneys had joist notches in them to carry the weight of the roof rafters. Almost all older homes had the framing tied into the central mass of the chimney for support. Anything as old as this will have some of the homes framing tied into the masonry.

I have examined a pretty large number of 18th and 19th century house in the Northeast and have lived in one for 40+ years. I can't think of one that used the chimney to "carry the weight of the roof rafters". Sound building practice transfers the weight of the roof via the rafters to the framing that extends downward to the foundation. This is true of construction which attaches the rafters to a ridge beam or board and employs horizontal roofing boards. It also applies to the earlier practice of purlins rather than rafters and roofing boards extending from the peak to the eaves. I have occasionally seen collar beams which haven been notched around a large chimney, but that's for a different purpose entirely. I believe that notching anything flammable and placing it in direct contact with a chimney would have been a serious building code violation long before the '70's. I'm also mystified as to how notching joists would have anything to do with supporting the weight of rafters.

So much misinformation. My 2 chimneys were built in 1779. There is some wood framing in the basement holding up the hearths, but no framing being supported by the chimney. I'm sure they've been repointed a number of times.

I have heard of chimneys carrying framing, but never seen it in real life. Head over to hearth.com with as many pictures as you can. The "design pros" here will be of no help...

A neighbor of my sister had a home not nearly as old as yours, probably 70-80 years old. She bought home 20 years ago. She decided to have a fire in fire place for the first time. Had never had a fireplace before. She ended up with a house full of smoke and called fire department. Luckily didn't burn home down. Was told to never use it again until fixed with a chimney lining at the very least. Chimney was cracked and could no longer be used and probably could not contain a fire.

Have you ever used fireplace? If so please don't anymore.

Thanks everyone for your input. I hope to learn more from the restoration company. Thus far, no one has gotten on the roof to lower a camera into the chimney, so they are only guessing at the condition of the joints on the inside.

The chimney is split in two flues, the smaller of which is used to vent our boiler (which has a steel liner as well). The larger flue is the fireplace flue and we knew the fireplace was non-functional when we bought the house, so no worries about us setting anything on fire. The fireplace floor and hearth were removed at some point so the current floor is just plywood held in place with nails - excellent workmanship!

I will take as many photos as I can and head the hearth.com while I wait for our appointment with the restoration company. Here are a few of the area around the basement framing that is visible - the chimney is surrounded by large beams but not touching any of them. There are some bricks sitting on top of one beam, but I believe they belong to the former fireplace floor/ hearth, since they are located directly below the arch of the fireplace opening:

Central beam running alongside but not touching the chimney:

Beam on the opposite side of chimney, again not touching:

And the false floor of the fireplace, just for fun:

Chimney restoration guy came today and said they could save the chimney. His plan is to carefully repoint the intact portions of the stack base first, then install a steel lintel below the fireplace arch before rebuilding the destroyed section. He'll also build a proper floor for the fireplace and repoint the exterior of the fireplace and interior of the firebox, seal the chimney with a plate just above the fireplace and install a proper cap at the top so we don't have to worry about further water damage. He also suggested NOT repointing the visible stack in the attic at this time, as he thought the mortar was in decent shape and that the bricks should be allowed to dry out fully before doing any more work. We are going to have a new liner installed as well, as he thought some of the moisture damage may have been due to an improperly installed liner.

DH wants to go ahead and book him, and I'm inclined to agree. Anyone see any glaring issues with this plan?

The "sealing" was in response to my asking him how we could stop the loss of conditioned air up the flue. The former owners just shoved a piece of insulation up there but I figured there must be a better way, and he told me their practice is to install a stainless steel plate where the damper would normally go, if the chimney is never going to be used.

As for the liner, they will install a solid stainless steel liner with a T joint at the base, which is apparently superior to the elbow joint we currently have. Our oil guy actually mentioned that to us once as well - he said the elbow joint allows buildup and debris to collect and clog the liner at the bend, while a T joint lets all that junk fall to the floor and keeps the path to the outside much cleaner. The current liner was installed in 2003 and I have no idea whether it was done or maintained properly, so getting a new one will certainly give us peace of mind even if it's not strictly necessary.

Another update - we had a second chimney company come to give us a bid on the work. They suggested pouring a concrete footer inside the stack and stuccoing the remaining accessible parts in the basement both inside and out, then installing a Proform liner, cap, floor, etc. Cost will be a couple thousand more than the other contractor, who was going to install a stainless liner. Anyone have any experience with the Proform system?

I have no experience with the Proform system which appears to be pretty new. I'd check on Hearth.com for further information and opinions. I did have a Supaflu liner installed more than 20 years ago which has performed extremely well without any problems at all. Others, however, have apparently experienced serious deterioration which may be due to improper mixing of the liner material. A cursory look at the Proform website shows that the liner is installed then inflated and cured with steam. This is different from Supaflu which pumps a semiliquid slurry around an inflated former. The material strengthens the interior of the chimney because it makes its way into any voids in the mortar and becomes firmly attached to the brick from bottom to top. I don't think this happens with Proform. I also don't think it's really possible to pour a true footer from within the chimney. Footers should be wider than the chimney and support its weight from below. Stuccoing (parging?) the interior would also be very difficult. Using this method on the exterior would be possible, but would not be, in my opinion, as secure as repointing the brick. Proform may be an excellent lining system, but doesn't seem to really do much for rebuilding and restoring your chimney. Rebuilding brick by brick, then using a stainless liner, which are fine, seems a better option to me.

Thank you akamaine. When the tech suggested Proform, I went to their website to see what other kinds of liners they offer and they listed several "cast in place" systems similar to the Supaflu you describe, which to me seem ideal for this situation given the unknown but likely imperfect condition of the inner mortar joints. I called the company to inquire but haven't heard back yet. We'll see what they say about that.

As for the "footer" and parging, the tech said that since there is already a large hole giving them access to the inside, they would repoint the non-damaged sections first, then pour the base through the hole and parge the inside before closing the hole, and finally parge the exterior. I understand that a proper footer would be wider than the chimney but I thought that perhaps a solid base plus parge coat would be a reasonable alternative given that it's not possible to pour a footer all the way around the base, due to the position of the boiler (situated just a few inches from one long side of the stack). I do worry about the pressure from the poured concrete blowing out the walls of the chimney, but I assume they will either build a frame around it to support it during that process or wait to pour the base until the repointing is fully cured.

Pressure from the poured material on the walls of the chimney will be a factor in any system like Supaflu. A neighbor tried to have his cica 1806 chimney Supflued, but the company declined doing it because of the risk to both the outer walls - a slight risk - and the brick that kept three flues separate from each other - the major risk. A good deal depends on the skill level of those pouring cast in place liners. The person doing mine knew almost instantly that there was a leak when a long forgotten and hidden rusted cast iron cover -placed where a wood stove was once vented - was dislodged and allowed the material to flow out. It was a relatively minor repair because it was caught so quickly.

This is great info, akamaine - thank you! This chimney does have a section of brick separating the two flues so that could certainly be a factor. I don't have any absolute objection to the Proform system but I would rather not pay more for it if it doesn't bring any value to the party.

I'm not sure if this rather vague information will be of any help to you, but there are a number of relatively new chemical products used in masonry restoration. In the past few years I saw them being used on an early 19th century lighthouse and on a massive exterior curved brick wall in a house listed on the national historic registry just a short walk from here. As with any newish product, there's not much of a track record, but the standards for restoration of historically designated buildings are very high. Might be worth asking about.

Just an update with a happy ending - we got three quotes from chimney repair places and ended up using the company with the middle bid, largely because they were the only ones who got up on the roof to do a full inspection before writing up an estimate. They rebuilt the stack in the basement, filled it and then parge coated it - it is basically a block of concrete now, and solid as a...well, a block of concrete! :) They added a lovely new brick floor to the fireplace as well. New stainless liner and cap, and all is well. The company did a great job, so we'll be calling them when it's time to deal with our other chimney/fireplace!

I have a similar situation North Jersey resident. Any recommendations?

"Any recommendations?"

Start your own post with pictures and descriptions. A three year old post will not get you much in the way of advice.