Planning An Outdoor Stepping Stone Feature

[Miss B]

Hi Everyone,

 

My wonderful mum has requested a garden feature - she has an amazing garden which she has created over more than 35 years. She took a photograph of a set of zodiac tiles that she saw in Italy and has sent me the photo as inspiration on the concept of creating a zodiac stepping stone tile feature - to be installed on the ground (as opposed to tiling on a wall).

 

I have found a nice taupe coloured (her favourite colour) heavily grogged stoneware clay (the ceramic supplies guy recommended it for outdoor and durability, minimising wet-weather slips etc). I have drawn most of the designs and figured out a design of 12 large tiles.

 

Now - my issues for which I lack experience, and would love your advice:

 

Tile size

I would like the tiles to be stepping stone size to make them a real eye-catching feature. I measured the biggest foot I could find (yes I actually asked someone if I could measure their big feet!) - a size 12 foot and it is 270mm (10.6"). I figured to ensure the foot is placed firmly in the middle of the step, with plenty of room for not hitting the edge the tiles (which would continuously place pressure on the edges) then they would need to be 400mm x 400mm (15.5") wide and 30mm (1.1") thickness. I know at this size I'll need to dry long and well and scoop out some of the clay on the back (but not too much so that it weakens the tile and it cracks under people's weight).

 

Any tips or gotchas for sizing and creating tiles this size?

 

Installation

I have read up about installation types including installing directly on a bed of compacted sand/concrete (e.g. create a solid base of concrete and lay the tiles on top with outdoor tile fixture). However I also thought I could lay these paving stones and fix the tiles to these using outdoor tile fixture - this way the tiles have a solid (movable) base and I can potentially make them only 10-20mm thick as the paving stone becomes the major support. However I read on a paving site that having the tiles attached to pavers creates increased opportunity for water to get in between and, when cold enough for ice, the tile pops off the paver due to the expansion. This concerned me because my parent's house does get icy frosts intermittently in winter (but not snow).

 

Does anyone have advice for the best installation method?

 

Thanks & cheers,

B.

[Denice]

I have never tried making stoneware tile for the great outdoors but I have made murals.  Our weather is a lot more severe here so on my first mural I made up a small one and threw in the snow and left it there all winter.  I had done the freeze/boil test but wanted to make sure it was going to work before I started a 9ft mural.  When I make interior floor tile I groove out a grid pattern on the back like commercial tiles make sure you put some grog on the shelf when you glaze fire it.  You might do some snooping on some tile layers forums or landscapers and ask them about installation.  Around here we would use some pea size drainage gravel that was compacted. Good Luck     Denice

[nairda]

I'd recommend adhering your tiles with commercial 'thinset' to concrete stepping stones purchased from a building supply store.   I've used 15" x 3" round concrete stepping stones and then made mosaic tiles to be added to the top.  My handmade tile pieces are about 3/8" thick. Easy to dry and fire; and when coupled with the concrete base, they're very strong. Not sure how well it would work if you were trying to adhere one large tile.  Using a mosaic approach allows you to adhere the smaller tiles, making sure there are no voids. Then grout around the mosaic.  Using the mosaic approach might reduce the potential for one very large ceramic tile to crack.   My stepping stones have been outside for 2 winters in -5F degree temps with no problems.  

 

Perhaps make 2 of them, install and see how they do over the course of a year.  Adjust your technique if needed and then do the rest.  

 

Good luck!  Nairda   

[Miss B]

Thanks so much Nairda and Denice - greatly appreciate your recommendations!

[Rae Reich]

I'd recommend adhering your tiles with commercial 'thinset' to concrete stepping stones purchased from a building supply store.   I've used 15" x 3" round concrete stepping stones and then made mosaic tiles to be added to the top.  My handmade tile pieces are about 3/8" thick. Easy to dry and fire; and when coupled with the concrete base, they're very strong. Not sure how well it would work if you were trying to adhere one large tile.  Using a mosaic approach allows you to adhere the smaller tiles, making sure there are no voids. Then grout around the mosaic.  Using the mosaic approach might reduce the potential for one very large ceramic tile to crack.   My stepping stones have been outside for 2 winters in -5F degree temps with no problems.  

 

Perhaps make 2 of them, install and see how they do over the course of a year.  Adjust your technique if needed and then do the rest.  

 

Good luck!  Nairda

 

I think this method is your best chance at success, using a mosaic method also eliminates the difficulties of drying and firing a completely flat, thin 15" tile.

If you decide to make whole stepping stones of clay, perhaps Mum would rather take up the stones in winter rather than risk her custom pathway.

[MatthewV]

Thick pieces can be fired successfully if the ramp rate is very slow. 30mm (1.1") thickness actually isn't too thick. I wouldn't scoop out clay and would ramp the bisque at 80°C/hr to 650 (with a few hours candled at 100°) and 150°C/hr after that.

 

 

An icy frost is not enough coldness to worry about. Even a light snow every few years wouldn't be of great concern; the ground is not freezing.