Slate roof tiles with cob & perlite base

Hello Everyone,

I'm pulling out an old pine floor around my rocket stove, and want to put a fireproof floor around the feed tube.

One idea was a cob and perlite base with old slate roof pieces screwed through the wet cob/perlite into the pine sub-floor.

Any advice on whether the cob base is a bad idea, or whether the slate roofing (1/4" thick) will break if walked on?

I figured the slate would protect from sand rubbing off.

Thanks!

Adam

Hi Adam,

Recycle slate of roofs will sometimes work really nice for exterior/interior walls, back splashes, and other "low traffic" areas...

Even with "re-cutting and shaping" to clean the edges and a good bedding of lime mortar seldom is good enough to keep old roof slate from cracking badly underfoot. If it was the "shake" or other thick variety...(20 mm to 30 mm) these can sometimes be used...

Hope that is of some help...

j

Perhaps another problem is the solution thing? Can we assume the slate is going to break and intentionally break it up and put it down as a kind of terrazzo? I have no idea, just rambling.....

Thanks for the thoughts!

Any direction on making lime mortar? I've never done that.

Adam

Hmmm...I guess I wasn't clear earlier...6 mm (~1/4 ") old roof slate does not fare well on floors...

I am reluctant to even get into traditional lime tile bedding formulas and grouts, as I am worried of the strong potential for a great deal of work, money then having to tear it all up...

I do like Joe B's idea of "fragmenting it" into smaller pieces. I must strongly suggest...this needs to be done with a diamond wet saw. Just smashing with a hammer will only further delaminate, destabilize and degrade the slate.

If still wanting to move forward...the slate must be soaked in warm water, and bedded well in a mortar bed that is "just wet enough" not soupy...

I would recommend either of these companies for advice on which of their products to use and the proper mix...The are both great colleagues and probably the of the most knowledgeable in North America on lime, natural concretes, pozzolanics and related masonry products...Both great companies to work with...Feel free to name drop...

Natural Mortars Owner: Mike Edison

Lime Works Owner: Andrew deGruchy