# CMU stair set: Help



## Captainsls (Nov 8, 2007)

Hey fellas, I've designed this set of stairs. As a disclaimer, I don’t claim to be an "experienced mason" but have laid my fair share of CMU. I have one structural detail I need confirmed. The tallest landing and accompanying two steps will be a separate structure than the bottom set, simply due to the angle they meet. I'm planning on trying to tie them together with rebar somehow.
My question is, when I build these two "boxes" I plan on filling the larger one with angular crushed stone minus 6" to pour a concrete pad flush with the top (and veneering bluestone over the pad). Is compacted crushed angular stone a suitable choice for infill material? What else would you use to fill the cavity with? Crushed stone is almost fully compact when you dump it, hence my intuition to use it. The structure sits on a concrete footing below the frost line. Any help is appreciated.


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## CJKarl (Nov 21, 2006)

I would do as you plan. Compact well in 12" lifts. SHould be no problem. Just don't blow out the top course with the plate compactor.


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## CJKarl (Nov 21, 2006)

Also, it appears you are going to stucco the block. Why don't you just cut your block so you can lay the 2 sections together.


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## Captainsls (Nov 8, 2007)

Thanks CJ, the main reason I was going to avoid one unit was timing. The stone would migrate into the lower section and I couldn’t compact it well. If I do two separate sections I can have two guys working on one structure. I think the stone would blow out of the steps, from the top section down to the lower section as well. It should still act as one monolithic structure as long as I tie them together.
Yeah, the stucco thing. This is one of the only homes around here I have ever seen with stucco (cape cod, ma). I haven’t a clue on how to do it. Most of the stairs will "sit" into a grade and be backfilled with clean stone so you wont see most of the sidewalls. Good thing too as I question my stucco abilities.:sad:


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## Tscarborough (Feb 25, 2006)

I would be sorely tempted to do that as one unit, but other than that, looks good.


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## CJKarl (Nov 21, 2006)

Hey Captainsls, where are you on the Cape? Know of a guy named Pat? Earthworm Landscape?


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## custom patios (Jan 2, 2008)

hey Captain. i understand what you are doing but i think once you are into the construction aspect you will be hard pressed to find a reason to build the structures separately. keep in mind that you can tie them together but they will act independant of one another.your best best is to pour one footer and block up from there. incorporate a separation wall between the upper and lower stairs into your side walls. this way you can fill both upper and lower stairs with an open aggregate. just my opinion, but i think it will be a stronger structure than creating a "seam" between the two structures.


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## Captainsls (Nov 8, 2007)

Steve: I need to start sharing profit with you, lol. I envisioned the footer to be one solid piece but the separation wall is the answer, can’t believe I didn’t think of that.

CJ: That name sounds familiar, but I don’t know him personally. I'm just a few miles north of the cape in Plymouth county.


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