Chimney block question

[dmun]

I have a question for someone with masonry experience, like Unofornaio, or anyone else. I'm building up my chimney with flue tile and 4" concrete block. I want to use some chimney block sections to avoid some need to cut every block. If refractory mortar the flue tile in place first, how do I get the heavy chimney block in place around it, without knocking it loose? Alternatively, if I lay up the block stack first, how to I get that little bead of refractory mortar in place two feet down a hole?

Any suggestions would be appreciated.

[dmun]

Re: Chimney block question

Here's a picture of a chimney block and a 8" square flue tile. Those suckers are heavy.

[maver]

Re: Chimney block question

I'm no mason...

I assume you are doing flu tile, build up with block to top of tile, then add another tile. Your flu is tall enough (compared to mine where I did all the flu tile, then wrapped with brick) that there really must be a skill to it. It seems you could support the flu tile internally by placing braces inside the flu. Perhaps four 1x4 lengths (maybe six feet) with one end fixed (plywood spacer) at an outer size of the 1x4 assembly just less than the flu interior, then drop that end down the flu past the seam, and the free end of 1x4 is expanded to apply pressure to the flu (towels or rags could be used to apply expansion pressure without risk of cracking the flu). You then have an internal splint to reduce the risk of knocking the last flu tile loose when placing the block around the flu.

[Unofornaio]

Re: Chimney block question

I have a question for someone with masonry experience, like Unofornaio, or anyone else. I'm building up my chimney with flue tile and 4" concrete block. I want to use some chimney block sections to avoid some need to cut every block. If refractory mortar the flue tile in place first, how do I get the heavy chimney block in place around it, without knocking it loose? Alternatively, if I lay up the block stack first, how to I get that little bead of refractory mortar in place two feet down a hole?

Any suggestions would be appreciated.

You have to do one section at a time flue liner, block, liner, block, etc. I would not recommend the size block you have it looks really tight, there should be a good 2" all the way around I don't know if its the pic or what but it looks like you have about 1" this is too close.

Yes those blocks are VERY heavy, imagine if they were 2 footers that have to be heaved over head to get over rebar cages like we use for columns. If I remember correctly you did a fine job on the exterior brick work why use the ring block? The cuts are going to be all the same, why not just cut them on the ground all at once and use reg block? It also depends on your scaffolding set up if you cannot straddle the flue to set the ring block, with that clearance your gonna have nightmares all the way up and out.

So here are your options as I see it;
1. Get the next size up ring block.
2. Get standard 4" block
3. If code will allow you get the rings in a split (2 sides) these are easier to lift but a little tricky to lay but still go faster that standards.

If you have to keep the block for some reason like I said if you cannot get right up close to this close enough to reach your arms around the flue liner forget it you HAVE to get bigger blocks or CUT the ones you have but that is still very close. If you can get close you just are going to have to go SLOW and steady the mortar for these blocks wants to be VERY stiff.
Make sure you keep everything plum and level or before you know it you will not be able to fit the block on because you're outa wack, with the little bit of clearance you have that could happen in as little as 2 blocks.
I hope this helps.

J.P.