# Building a an exposed aggregate sidewalk with river stone



## WayneBollman (Jun 3, 2012)

Hi. I'm new. Not sure if I'm in the right forum for this question but I'll give it go. I need to build an exposed aggregate concrete sidewalk (using river stone approx 3-4" in diameter) that will wind down a 15 degree hill slope gradient for about 30 feet.

I'm concerned mostly about the gradient. Will this have to be stepped or can it be done contiguously without steps?

In either case, do you have to build a custom 2x4 frame (as I see most regular sidewalks made)? What about gradual curves? Could I use something like flexible plastic landscape edging for the framing and then remove the edging when finished? I've got a lot of experience with building various kinds of walkways/paths, but I've never built a concrete sidewalk of any kind. 

Any help/advice would be deeply appreciated, but ideally you should assume you're talking to a complete idiot. I'd love to see some step by step instructions for this if possible.


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## WayneBollman (Jun 3, 2012)

*A photo example*

Here's a picture I found online of approximately what I'm trying to do: http://www.renovateyourworld.com/MyProjects/images/UserImages/506-small.jpg Imagine this about twice as long and on a slight slope and slightly curved in couple places. Also, what about expansion joints? Do I need them? This is in Austin Texas (very hot in summer) but in the shade. Since posting this I was told I could use thin flexable fascia board (with stakes) for the curved framing because it's relatively cheap and easy to work with. Does that make sense?


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## user1007 (Sep 23, 2009)

That is large stone to be trying to pour as an aggregate mix. I wonder if the picture is not showing stones laid and place and then surrounded with a reinforced mortar? Rounded stones of that size might be hard to walk on? Fat top cobble stones are going to get pricey. 

You might explore staining and stamping concrete with a cobblestone pattern.

Where are you by the way. You might want to update your profile so we know. Exposed aggregate does not work out so well in freezing climates.


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## WayneBollman (Jun 3, 2012)

I didn't mean to imply that I'd be pouring it this way - that would have never even occured to me. I'm referring to it as "exposed aggregate" because I was told that this is technically what it is, not because of how it should be built. I'm doing this for someone else that's hellbent on using these river stones for his walkway. His neighbor has done this and it looks good and he wants the same thing. He's not interested in doing it any other way; he'd probably just as soon do nothing at all. He previously tried to do this himself by simply setting the stones in place then pouring mortar over them to fill in the gaps. After this hardened and was walked across for about a month or two it started to break apart .... assumably because this requires a concrete foundation, not just concrete in between the stones. So I figure I'll be trenching about a 6 inch deep path first.


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## KevinPh (May 25, 2012)

The building code in most places has a maximum 8% slope for a walkway. For a 15% slope, you would have to put in stairs in one or two locations to stick to the 8% slope.

You may want to check with your building department to check the standards.


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