Need to fix fireplace/chimney before installing direct vent gas insert?

[BurningDownTheHouse]

We moved into a home last year that has a masonry wood burning fireplace with some issues (noted below, per multiple inspections that we had done). We have not done anything with it, and are now wanting to convert to a direct vent gas insert.

The companies who provided the inspections last year say that we still would need to make all or most of these fixes before putting in the insert. This doesn't make sense to me. I would expect that the top needs to be waterproofed either way, but why should I care about mortar gaps in the smoke chamber and lining if the by-products from the insert are removed out through their own vent?

Apparent issues identified by the inspections:

Smoke chamber: Stage 3 creosote; Gaps/missing mortar.
Fix: Respray with high heat ceramic mortar (smoketite or Chamber tech?)

Flue system: deteriorating/missing wythe joints;
Fix: new stainless steel liner

Profile joint and firebox: needs touchups

Exterior: Spauling? brick missing; missing/cracked mortar joints. Improper install of flashing
Fix: 3-stage waterproofing: resurface top portion with crownsaver (rubberized elastomeric coating) saturating entire stack with chimney saver water repellent, sealing flashing and all missing or cracked mortar joints.

This is one of the responses I got when I went back and asked about a direct vent alternative (he did recommend gas logs)
"I am not sure why you want a direct vent insert. It is not necessary, you still have to do all the other work, (smoktite, waterproofing, crown etc.) and install a liner."

Does reference to still needing a liner just refer to the co-linear fresh air/combustion tubes? Seems like that is way easier than the stainless liner needed to fix if keeping wood burning

I really appreciate you reading this and welcome any insight or recommendations you have.

 

[Doc C]

Gas or wood chimney has to "contain the products of combustion".

Of you are using the existing chimney to vent the gas stove then it needs to be fixed.

If you are going to use a liner that attaches to the fireplace and goes all the way to the top and attaches with a top players then I see no reason to have to repair the cracks in the chimney.

One point I will make. If you do not remove the cresote prior to lining I think you have a good possibility of getting the cresote smell in the house during the summer time.

If you have ever smelled cresote in the summer time in a house you know it's something you want to avoid if possible.

Also anything that allows water to penetrate from the outside would be my priority before anything else regardless if you are going to use the chimney or not.

 

[Doc C]

One other thought after looking at the pics again. If the cracks inside are going to become a structural issue down the road then it might be worth fixing now as opposed to having to pull the liner and fireplace out in the future l.

 

[BurningDownTheHouse]

Thank you for the response. That all makes sense.

We definitely had the occasional strong smoke smell this summer; I guess I’m hoping that a tight seal on an insert would keep that from drafting in

 

[Doc C]

Thank you for the response. That all makes sense.

We definitely had the occasional strong smoke smell this summer; I guess I’m hoping that a tight seal on an insert would keep that from drafting in

If you want to keep the smell out I would go through every feasible solution you can prior to lining. Obviously some stuff is cost prohibitive.

I have completely sealed my chimney in the summer and still get the smell. I know it doesn't make any sense....and that's part of my problem. I am having my chimney relined and I'm burning a lot of a Manganese containing product in an effort to get my cresote glaze to convert to something I can sweep.

There is what sweeps in my area call a poultice which is supposed to remove the glaze but it's cost prohibitive in my case.

 

[Woebegone]

One other possible source for that summer smoky smell is your clean out. Even if you completely remediate the chimney, if the negative pressure created by an AC blower can draw air over the ash and creosote bits some people dump down the clean out, you might end up with a summer stink.