Unlined Chimneys

[jschneider]

Anybody have any experience with unlined chimneys?

We had our original fireplace inspected last month, and the inspectors found it to be unlined. Not uncommon in an old house, but they said not to use it. They weren't too helpful about getting it lined either... they didn't seem to think it could be done effectively because of the bends, diameter, etc.

The PO's were using it up until the day we closed on the house. I'd love to see it in operation, now that we're having some of those chilly, rainy fall nights.

[Texas_Ranger]

Having seen the conditions of some old chimneys (mortar missing, traces of soot all the way out to the plaster on the surface) I wouldn't feel too awfully comfortable using a completely original chimney. However, in Europe there is a rather simple way of improving small diametre flues. They simply give the flue a good cleanout, run a rope down from the roof, tie a piece of old foam mattress to the rope and use it to drag lime plaster up the flue. I don't really know how to make sure you cover the entire surface without missing spots though.

[SkipW]

There are several companies that specialize in lining chimneys.

Our house has two styles.

One is a stainless steel liner that is pulled up or down in a single flexible tube and then secured mechanically or with a mortar slurry around the outside of the tube. This style was done on our chimney for the boiler. (brick, built in 1936 originally for the kitchen stove in the 1936 addition)

The other is (IIRC) from "Supaflu" and is done by creating a dome shaped cone that fits the desired opening and is started in the fire box and pulled up the chimney while a semi-solid lightweight cementcious slurry is pumped down the chimney. The cone presses the slurry tight to the chimney walls, filling gaps and bonding loose bricks, etc, while forming a centered flue of the diameter of the cone. This was done on our fireplace (site built with stone from the property in 1907)

These are both good for regular and oddly shaped chineys as they can conform to curves and turns.

The approximate cost, depending on length of the chimney, would probably be in the $2500-$3500 range.

Hope that info helps!

[shazapple]

Our chimney was unlined when we moved in and the previous owners used it, although we didn't until we had it lined. Lining makes it easier to clean and provides a continuous passage for the smoke. A chimney with shelves and nooks can have stuff collect that could catch fire.

Ours was lined with a flexible liner, kind of like that flexible ducting. We had a WETT certified contractor install it, who would be better suited to tell you what to do with your chimney than a home inspector.

[jschneider]

Thanks for the responses!

You can see daylight from the fireplace, but there are a couple offsets at the floor levels. Also, as mentioned, there are smoke shelves. It's actually pretty cool! It was originally a coal burning fireplace, which can apparently soften the mortar also.

The guys that inspected it were certified chimney inspectors/sweeps from a company that does just that, including lining chimneys. I think I need to get another opinion from somebody that may actually be interested in doing the work.

Skip... our fireplace chimney runs 3 floors, plus an attic... I'm thinking it would be on the $3,500+ side of the amount you had said, which is WAY more than I was hoping to spend.

[csnyder (WavyGlass)]

We're getting our chimney relined this week, using the second method Skip mentioned. Cost is in the $3000 range for a two-story chimney. Our liner is mostly intact, but there were some gaps in the joints that I'm concerned about.

[brian89gp (WavyGlass)]

Burning wood in an unlined chimney will lead to a chimney fire and possibly a house fire. Not really a question of if, but when.

Are you going to be burning in an open fireplace or with a stove insert? Any modern stove will probably require a smaller diameter Stainless Steel liner (usually 6" diameter, plus 1" of insulation), which is good because a smaller diameter flue is easier to fit down the chimney. If you are using it as an open fireplace you will probably have to look into having it lined with tile and/or the pour in cement method. A stove almost always will put out more heat with less wood then an open fireplace will.

Two reasons you need to get it lined:
1. Creasote. Unless you have a somewhat smooth liner you will get creasote buildup and it is impossible to get it cleaned off the brick in the unlined chimney. In addition, people who burn casually (eg, only on cold nights), usually are not as good at burning a hot fire (less creasote production) and are less likely to have properly seasoned wood to burn (unseasoned wood = more creasote). Too much creasote = eventual chimney fire.
2. Heat. The heat in the flue heats up the brick, the brick heat up and can catch the wood on the other side of them on fire. Especially true when your chimney decides to emulate the surface of the sun during a chimney fire.

A coal burning fireplace and a wood burning fireplace are two different animals, mainly due to wood having creasote buildup. With coal, all you get is soot.

For a flexable SS liner, 40' of 6" smoothwall is around $900, $200 for insulation, and the same amount in materials for installation. I do not know pricing for the pour-in liners.

[jschneider]

We fortunately have no intention upon using it to burn wood until it's lined. Our intention is to keep it a fireplace with no insert.

I had no idea lining it was that expensive! I had $1,000-$1,500 in my mind for some reason.

[hoosier foursquare (WavyGlass)]

Up until last week we had 2 unlined masonry chimney's in our 3-story, 1901 limestone American Foursquare (Inspired!) home. Now we only have 1!

We had the following installed: A Lopi 1250I woodburning insert, 40' MFLEX Stainless Steel Liner and chimney cap. It cost around $3100 for the whole shabang.

Both fireplaces were originally coal burners with one being located in the Sitting Room off of our Dining Room and the other was in the original kitchen. When the house went through extensive re-muddling in the 1950's, the Sitting Room fireplace was deactivated and the room was converted into a full bathroom, hallway & closet. The fireplace in the kitchen was coverted into a see-through/double sided fireplace and was being used up until the 1990's.

We have looked at a couple of options for the kitchen fireplace:

#1 - Wood burning: Remove rusted damper, stainless lliner w/ top opening damper
#2 - Woodburning: Remove rusted damper, poured liner (SupaFlu), top opening damper.
#3 - Gas Burning: Remove rusted damper, stainless liner, chimney cap, gas burning logset.

The cheapest is the gas burning option. I really like being able to burn wood but the convenience the gas log is pretty nice. But, the price range in my est. is $2000-$3000 either way.

I've attached a couple of pictures. The first two are of our Sitting Room Fireplace post-bathroom, hallway, closet demolition, pre-restoration. The third picture is of our kitchen fireplace (kitchen side) that still needs to be lined/fixed to get it in full working order.

It was a great feeling to light the first fire in the Sitting Room fireplace knowing that there hadn't been one lit in over 62 years!

[lisascenic]

What exactly is "lining" anyway? I honestly don't know what this is, and I figure I'll get an honest answer (and not a sales pitch) from you folks.