Flue repair - quick/decent fixes for terracotta brick

Hiya,

[I'm new to the forums but have been lurking for quite awhile.]

I'm about to buy a FPX Large Hybrid Fyre and am hopefully getting a new flex liner kit from Rockford Chimney Supply this weekend to get everything ready beforehand.

The last clay (teracota) section of the flue that sticks out of the chimney top is not looking great. The house was built nearly 60 years ago and it's original. [Please see pics.]

Questions:
1) Since I'm putting in a liner anyway now, can I just firm up the clay with some refractory cement (or something else)?
2) If no on 1), can I replace just the top piece of the clay flue with a section of a new section (from the cement chimney crest on up), and use refractory cement to bind it in?

The clay section measures 8" x 12" and I think I'm seeing where the big box stores (HD, Lowe's) sell them in 2 foot sections. I probably need the top 8-10 inch section replaced.

Many thanks in advance for any advice you can offer.

Rick

Thanks a lot for the reply, Lake Girl.

I'm really hoping to do this myself if possible, and am not sure that repairing the (fireplace only) clay flue is really needed given that it'll soon have a liner in it anyway.

The goal is to do something reasonable and/or cosmetic unless there's a good reason to do more.

Begreen, can't I do that by myself?

I'm sure a mason would do a better job, but as long as it's sealed well (with refractory cement), esp. around the crown, it's hard to understand what I could do wrong.

I'm happy to add a chase too, if that'll help. Water seeping into the brick via the crown seems like the biggest risk here, from my current understanding.

[Thanks Lake Girl!]

bholler said:

I would just cut that liner down flush and install the stainless liner. But it looks like you need a new crown. Plants growing out of the top of the chimney are never a good sign

Click to expand...

bholler, thanks a bunch for the reply. Making it flush sounds good if meets code. The furnace flue clay is right next to the fireplace one and in better shape. I could make both clay flues flush or just one, but don't know what I'd attach the rain cap to if it's flush. I guess I could rework the cement and add a rain drip overhang, and then put a chase over it all, and attach the rain caps to the chase. Your recommendations would be most welcome.

My bad on the plant. "Fixed" the crown ~7 years ago with a combo of regular cement and bonding cement (when I ran out). Either I didn't go right up to the clay with the cement, or the cement pulled away when it cured. Is there something I can use to seal between the cement and the clay?

Two more issues if you could be so kind:
1) When I install the insert (in the current fireplace pit), I may have a space issue with a GreenStart add-on. Is it ok to take out an existing firebrick, cut it in half, and then re-mortar/tuck-point around it using refractory cement?
2) For tuck-pointing on the outside of the chimney, do you use a mix of Type N cement and sand or something else? [If so, what mix?]

Hi BHoller,

The furnace clay liner looks fine in my case. Only the fireplace chimney liner looks like heck.

This weekend, I took some refractory cement, mixed in some terracotta color mix, and tried to patch it up. I'm not fully sure that it'll bind, but this is what it looks like. I'll never be confused with a real mason, but it seems pretty functional.

Next weekend, before I put the liner down the chimney, I'll put some refractory cement around the base of each clay liner where it connects to the white+gray cement chimney cap, to try to prevent growth of weeds, etc. I'll also put a light layer of new cement on the chimney cap so that it looks uniform.

Thanks for all your help. If you have any comments on the above, please let me know.

Many thanks to all for your help.

Thanks again guys.

Code says that the chimney must be 3' above the junction with the roolf. I just need to measure that height a bit more precisely to make sure that I don't need the ~6 inches of terracotta tile to make it to 3'.

I've noticed some bad mortar on the roof side of the chimney when I was up there last weekend. Is there a strap or mini-scaffolding that I can use when working on my roof to attach myself to the chimney so that I don't have an accident?

Also, the (6") flex liner plus insulation is a bit over 7 inches, and I'm getting stuck when I am going down my 13" x 8" terracotta flue. It's ok to elongate the tube to make it fit better, yes?