Quartz rock chimney?

greenspun.com : LUSENET : Countryside : One Thread

I am planning on doing some MUCH needed renotovations to the house here and I plan to build my own chimney. I have some quesions reguarding the choice of stone (and I do want stone as it will be the "focal point" of the front of the house). I have a LARGE amount of dry milky white quartz stones on the land here. They are NOT creek bed stones. They are pretty uniform in size and were probabally used in a stone wall a hundred or more years ago. Many have a nearly cut look to them and would be nice- to my mind- for building with. My question concerns if quartz will hold up under moderate heating and cooling- the chimney will have a flue. Quartz is a crystal and might react differently? than, say granite or sandstone. Also, while I understand that a good footing is essential in a chimney, how would I go about attaching the chimney to the wall- as the house is made of cinder blocks.. or should the entire chimney structure be independant? Still thinking on ideas on how to pipe the stove pipe/ flue through the cinder store with out heating the inside of them up (there is wood a couple of feet up at the top of the inside of the cinderblock wall).

-- Kevin in NC (Vantravlrs@aol.com), December 13, 2001

Answers

I do not know about the suitability of quartz, but for the other answers; in masonary there are galvinized straps that could be anchored into the existing wall, then laced in to the new stonework. Sandy soil needs a foundation of 12 inches deep and a width of at least 8 inches beyond the width of that much tonnage. Keep in mind that the color of split stone is much deeper that the surface color, if it is what your after.

-- mitch hearn (moopups@citlink.net), December 13, 2001.

Make sure the wall you're anchoring to has enough strength to handle the stress; for instance, are the blocks full of concrete and steel? Use heavy straps: talk to your local distributor of chimney liners, or whatnot. Use ceramic chimney liner (it's a product specifically designed for this). Run proper amount of rebar continuously up from inside the footing to the top of the chimney, with concrete surrounding the liner, then rocks outside the concrete. This is the most important aspect, besides anchoring and footing.

River rocks, imho, are not a problem in chimneys; people use them successfully here all the time. However, regardless of what kind of rock you use, I'd line the fire chamber itself with firebrick, and use high temperature mortar.

Quartz sounds awesome! Quartz is normally a very stable stone, assuming it's not rotten.

Have fun! (more advice: overbuild the hell out of the footing; the chimney is likely to be EXTREMELY heavy!)

-- joj (jump@off.c), December 13, 2001.


Your quartz might or might not be good. Here are the differences. If it is metamorphic quartzite - microcrystalline to fine crystals, and having been subjected to moderate pressures and temperatures through metamorphism, you will find the stones to be fairly refractory and quite suitable for your project. If the stones are pegmatitic quartzite, and composed of large to very large crystals, heat applied to the non-homogeneous coefficients of thermal expansion along the growth surfaces will very shortly reduce your stone to rubble.

So how to tell? If you knew what to look for, sacrificing one of the stones with a hammer will show you. But easier would be to build a small campfire with one such stone at the flame's perimeter. Once the rock is good and hot, shove it directly into the coals. You'll see the result the next morning, one way or the other. If your plan is to build the chimney just using the quartz to face the exterior, you have a lot more leeway; still, any coarsely- crystalline rock - quartz, feldspar, amphibole - is a poorer choice than a fine-grained one. Good luck!

-- Audie (paxtours@alaska.net), December 13, 2001.


I have a quartz fireplace, takes up almost the entire wall. It has a passive heatalator and the inside has been lined with 1 inch steel. This fireplace was built in 1948. There have been a few roaring fires in it since then.

-- westbrook (westbrook_farms@yahoo.com), December 13, 2001.

Wow Audie, Might you be a geologist?

-- buffy (buffyannjones@hotmail.com), December 14, 2001.


usedtobe, Buffy. (M.S.Geochem&Mineralogy)

-- Audie (paxtours@alaska.net), December 14, 2001.

Audie, I studied a little bit of geology in college, years ago. I thought pegmatite was a form of granite, which contains large crystals of quartz, but also lots of other minerals.

And I thought metamorphosed quartz was quartzite.

Clarification?

JOJ

-- joj (jump@off.c), December 14, 2001.


Moderation questions? read the FAQ