Type S mortar

[Les]

Does anyone have data on the temps we can expect on the flue. I want to use type S on the brick around it but cannot find any data on the temp rating. I googled it and some have used it on their chimneys - doesn't make it right. Trying to avoid more of rolling my own.

TIA,

Les...

[dmun]

Type S mortar is not a refractory product. Building code calls for a half inch air gap between the flue liner and the masonry outer wall.

[Les]

Thanks David, I was afraid of that. But after going this far, whats another 30 minutes or so of mixing?

Les...

[bernerdog]

off topic a bit, but if you build the brick up and over the tile flue pipe maintaing the space suggested by Dmun (and code), how do you seal it at the brick top and avoid water infiltration down the flue and into the vent area, base, etc.? Thanks John

[jengineer]

you put up a localized force field around it. Come on every sci-fi geek knows that!

[Les]

Originally Posted by bernerdog

off topic a bit, but if you build the brick up and over the tile flue pipe maintaing the space suggested by Dmun (and code), how do you seal it at the brick top and avoid water infiltration down the flue and into the vent area, base, etc.? Thanks John

John - not quite sure how the top is going to tie in, I'll burn that bridge when I'm on it.

Les...

[dmun]

The top is aligned to the flue tile stack with the chimney cap. If you buy a pre-cast cap it's designed for the flue to slide in and out of the masonry housing. If you cast your own, the flue tile is wrapped with flashing, so the flue tile is at least theoretically loose. Here's the picture of how I did it:





Can some water get in? Yes, a little bit. I assume it's designed that way.

[George T]

Les, type S mortar is what masons use in the brick around the Flue liner here in the midwest.

[rlb444]

Type S mortar specs=1 portland, 1/4 to 1/2 lime, 3 sand, 1800 psi compessive strength. A better mix would be type N mortar specs=1 portland, 1/2 to 1 1/4 lime and 3 sand for a comressive strength of 750 psi. The lower compressive strength of type N is ideal for a wfo as that equates to an increase in flexibilty. Even better would be to add 1 part fireclay to your type N mortar.

[amber]

dmun - can you explain the flashing bit a little more? Thanks!