Installing Slate to Existing Concrete Stairs

JimMorrissey · Sep 2, 2005

Hey guys.....

I have these ugly concrete stains that I want to cover in slate tiles. I have enough slate in the barn to cover all the concrete (treads, risers & sides), but am unsure on the best way to apply the 12x12 slate tiles for long term use. Any ideas or suggestions would be helpful. I guess mortor is the thing to use...maybe not.

Have a good holiday weekend.

ronjhall · Sep 2, 2005

Indoors or outdoors?

Bob_Skurka · Sep 2, 2005

Jim, I'm guessing you are talking outdoors?

If so, go to a high quality tile dealer and ask for advice. You will likely need a waterproof mastic to hold them in place and a waterproof grout. I built a small outdoor kitchen area to hold a Weber grill (not one of those fancy ones like OkeeDon built). I used a ceramic tile instead of slate/natural stone. Its been enduring Chicago area winters for 5 or 6 years with no problems, but I did have to use special adhesive and grout. I'm just guessing here, but you may have to put a sealer over the slate to keep water from soaking between the layers of it. Water soaking into slate and then freezing in your Vermont winters would likely flake the slate badly in just one or two seasons???

JimMorrissey · Sep 3, 2005

Sorry....I thought "concrete stairs" would tip it off that it's outdoors /forums/images/graemlins/smile.gif

JimMorrissey · Sep 3, 2005

Bob,

I'll do some more research. Figured I'd start here first.

Slate doesn't absorb water. It's very dense and is used on roofs all around the area here. Our roof is slate, as is the barn and the garage. Not sure if you might be thinking about some other rock type material that absorbs water. I do agree that water might get between the slates and pop them off when it freezes without the proper "grout". I'm figuring standard mortor is going to work. I'll post my solution at some point. Tile would be too slippery when wet for a stairs. Slate has a nice smooth surface, yet rough enough for a good grip on stairs.

Bob_Skurka · Sep 3, 2005

Jim the reason I mentioned the sealer is because slate is a layered natural stone (don't know the technical term for the layers) but slate on a roof will shed water because of the slope. Slate on a step may not shed the water. If water gets into the slate it would very likely flake as the water freezes and expands. Just my theory anyway.

I'm a novice tile setter, my uncle did it for a living, I do it for fun. So I'm not sure what you will face with the slate but it seems like a reasonable thing to worry about with water/ice sitting on it? Freeze thaw cycles do wonders at tearing up man made projects very quicly if water seeps into them. I do know it is nice looking and long wearing on a roof. My dad had slate in the foyer of one of our homes and mom waxed it a couple times a year for looks but was trouble free for the decade we lived there, but again, that was inside.

ronjhall · Sep 3, 2005

Well I had to ask. /forums/images/graemlins/blush.gif My response for outdoors would have gone along the same line as Bob's. /forums/images/graemlins/wink.gif

Dargo · Sep 3, 2005

May I add that slate on stairs makes for a hard landing if you trip. About a week ago, while wondering into my house in the early morning hours (I don't sleep much), I stumbled over a sleeping dog and fell on my slate steps, cracking the coronoid process of my ulna where flexion of the forearm is received into the coronoid fossa of the humerus.

At least that's what it says on this Dr's interpretation of an X ray that I'm reading. All I can say is that if you fall on slate steps, it hurts! /forums/images/graemlins/blush.gif And, no, I wasn't drinking! I don't drink, but I'm seriously considering taking it up at the moment... /forums/images/graemlins/tongue.gif

In case you are wondering, no, I didn't hurt the steps any. They still look nice, and the blood wiped right up since I'd treated the stone. /forums/images/graemlins/wink.gif

JimMorrissey · Sep 3, 2005

Bob,

True "slate" from the NE does not absorb water and flake off. It is true stone in the real sense of the word. Now "flag stone" may flake off and crumble over time, but not real quality slate. We live in "slate valley". Something like 70% of the country's slate comes from within 20 miles of here.

As an aside......My parents have a slate porch and a my brother has a slate stairway. There has been no flaking in over 20 years of harsh Vermont weather.

JimMorrissey · Sep 3, 2005

Well the stairs are currently concrete, so the possible fall would be equally as harsh /forums/images/graemlins/smile.gif

My kids are familiar with the falls on slate. Our last house had two slate bathrooms and a slate kitchen with radiant tubes underneath. It was hard for sure....but oh sooo nice to walk on in the winter.

Glad to hear you are OK!