masonry chimney

I am considering building a masonry chimney (if the DVC500 isnt desireable). I was going to use concrete (cinder) block up to my cleanout...then I was going to use 16x16 chiney block the rest of the way lining it with 8x8 2' clay liners starting above where the stove pipe enters. Is this overkill on block and liner??? I need help with this!!!

They make 'thimble block' that are already partially shaped for a flue pipe, and this way you can use 16 by 16's all the way up, no need for separate cinder blocks. The clean-out can be made through the flue blocks just by gently making the opening 'square' and off you go up to the flue entrance. No need to lay separate blocks, you only need two sets of thimble blocks and ordinary 16 by 16s for the rest of the job. Check with any masonry supplier of lumber yard, They'll show you how to proceed. You will need to buy mortar mix anyway, a clean-out, a thimble, etc.

Whistlenut thanks.....I was going to use cinder block on the bottom because it was cheaper....is there a difference between thimble block and chimney block??? Isnt chimney block be semi circle already to mortar your clay liner in??? I am new with this stuff

spend the money and make sure you put a clay liner in it, and size the flue for its purpose

Sorry, I assumed you would be installing a clay liner....and I know you are, You can go with square or round flue tiles, and the opening I was talking about would be in the side of the chimney, not the vertical portion. The thimble block have semi circle already prepared. You can not buy them already prepared, but it is worth the extra buck or two to have the things done. Remember to saw-cut the clean-out hole and flue hole into the flues before you assemble the thing.
You can try to create the openings by hand without sawing, but you might need to purchase a couple extra flues for that adventure. If they call you "lucky", please disregard.

Building Code here says that you must use refractory cement between the flue ends as you ascend toward the top of the chimney. It is not cheap (50 bucks a bucket- enough for a 25' chimney), but the masonry cement will not withstand constant heat (wood fired device, coal doesn't matter, as you know) and acidity of oil fired appliances. We both know that there are millions of chimneys without refractory between the flue ends, but I do it now, and feel safer for doing it. Don't forget about wall ties to anchor the chimney to the building surface, and include a couple large heavy duty straps lagged into an overlay or rafter as you go up.

I was sure you were using an 8" flue in the 16 square chimney block.......

I have been told a round flue is better, I put one in and its been great. Plus you can get round tile that fits together with a male and female end type fit..

Whistlenut> I love NH....used to vacation in Lincoln and Conway....NOW I have gotten prises on 16x16 block and 8x8 clay flu..so thats what I was going to use.....Do you have to use chimney block or can you use regular cinder block lined with the clay flu??

I used 8 x 8 tile with chimney block over 28 years ago. I coated the footing with refractory cement prior to setting the first tile, and all joints of the tile are set in refractory cement. I also filled the air space between the tile and the chimney block with mineral insulation to help keep the convection of the chimney going in the colder weather. The chimney is inside my heated garage, and the tiles look like day one after over 28 years of burning coal, just wipe your finger on the tile inside at the thimble, and you see the original gold color. Masonary is forever

You don't have to use chimney block, but it is easier, faster and stronger....plus only one block to handle per course instead of 4. Your choice. My vote is use chimney block. Make damned sure you have an adequate footing under the chimney before you start!.

Whistle: Thanx I was going to make my footer 4' down and allow 4" pn all sides.....I was going to use high PSI poor and reinforce it with re-bar. Thought about webbing the re-bar then placing it in the hole and pooring crete after that.....

go wider than 4" and pour it thick.

In your area's can you get chimney block of the right size to

enclose a 8" round flue with the bell ends?

I can only get the 8'x8" square straight liner blocks which

only barely clear the flue lining.To use the belled liner

a brick up chimney is needed.


BigBarney

superior clay and a few others make round male/female (self-aligning) liners with no bell end - think ship lap

Finally got the time this morning to go to my local masonry supply yard for chimney build materials . Told them I wanted 8" round flue liners, self aligning preferred. The guy said he'd never heard of such a thing. All they carried in round 8" was thimbles. I told him about Superior Clay Tiles mentioned by others on this site and their self aligning flues and precut tiles for thimbles and clean outs.He said I must be talking about bell ended sewer tile ! Also stated regular chimney block wouldn't fit around 8" flue tile ( outside dimension is about 10" ). Left empty handed and frustrated ! Anyone recommend a retail supplier within 100 miles of Ashtabula,Ohio that carries the tiles and block I'm looking for ? Thanks.

contact superior clay and ask them: http://www.superiorclay.com/contact-us.php

Btw, there is "chimney block" specifically designed for round tile liners : http://www.stonyrunsupply.com/imagegallery.php

Having said all that, I really wouldn't sweat it too much if you decide to use square block and tile, it's not bad, it's just that the round is a little better; of course much more important than that is planning to go high enough with the stack - round or square won't matter if you don't build it tall enough! I use square and rectangular all the time. Use logan or superior clay tile, I feel that Kopp liners (more yellow orange than red in color) are a bit more prone to spalling and deterioration than the other two I recommended. Good luck w/ your project!