Hi.
I am replacing the concrete stairs to my basement. There are 5 steps, including the basement floor level. The run is approximately 4 feet. The existing concrete was not done well, and is cracking apart.
My original thought was to form and pour concrete steps (I’ve done this before, and am familiar with it). However, the stairway sits between two existing retaining walls, 36″ apart. I don’t think it would be possible to remove all of the forms, and I don’t want to leave the side pieces sitting there rotting and looking ugly.
So I decided to build my stairway out of block. What kind of footing do I need?
Thanks,
Alex
Outside of a dog, a book is a man’s best friend. Inside of a dog, it’s too dark to read.
-Groucho Marx
-Groucho Marx
Replies
8" thick concrete.
same footing you'd use for poured crete steps normally.
But this is between two walls??? Are these concrete walls?
If so, they each have a footing so those two nearly touch or are already co-joined likely.
Also, forming, pouring, and removing the forms for a set of steps between two concrete walls is very easy. I don't know how it would be hard to remove the forms.
You build the steps in reverse and once the crete cures, the wood is all on top. About six tapcons is all you would need to remove first - two or three in each side stringer.
edit - forgot to clarify where I was going with that thought...if you drilled rebar into the side walls for these and poured the steps, you should not need a footer.
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Edited 8/16/2009 10:02 am ET by Piffin
The steps are going between two parallel retaining walls, about 36" apart. One side is a 90-year-old brick wall with no footing (!); on the other side, I am now putting in block to replace a section of the original brick where it got too funky. This, of course, has a footing.
When I poured concrete steps in the back of the house, I excavated enough to build a complete form, with sides. When the concrete cured, I stripped this and backfilled.
Do you mean that the sides of my form are above and outside the stairs? (I am just starting to visualize this...lemme go cut up some cardboard and figure it out.)
AlexOutside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
The sides of the form would be the two walls
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Make a few "risers", and attach these between the two walls. "Rubble fill inside the "forms" and add a few rebars down the cnter line of the stairs. A "dowel" (rebar) , epoxied into the wall at each tread location, with a rebar to connect the dowels through the tread. Use either a 3 or 4 slump to pout the treads/steps. Broom finish the treads. Note: on the 2x for the riser, cut a 45 dgree bevel along the edge that meet the tread below the riser. This allows you to trowel right into the back of the tread. Also, "tilt" the riser about 1" forward. That way you can get a wider tread in the space allowed. Instead of say, an 11" tread, the tilt would give you a 12" tread in the same "space". Be sure to hammer vibrate the risers to avoid "voids" ( say that three times real fast) and maybe an edger along the front edge of the tread. Yep, done a few of them.
Got it, I think.
I was becoming dyslexic trying to picture the forms in my mind.
Two further questions:
1. Don't I need to isolate the stairs from the walls? No expansion joint?
2. If I go with blocks, Matt (first reply) said I need an 8" footing underneath. Do I really need that much concrete underneath the entire stair?
Thank you to all who have helped me out with your answers.
Alex
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
Either way, just a "footer" under the bottom tread. Everything else behind those steps would be gravel in-fill. Don't really need an expansion joint. The "forms" would be 2xs as wide as your risers are tall. Then take a 2x4, screw one on each end of the riser form. Tapcon the 2x4s to the walls. On wider steps, a 2x4 gets screwed to each riser form, right up the "center-line" of the stair-way. This is for bracing the risers in place so that they won't "bow" out during the pour. Once the concrete has set enough, start striping the forms and start finishing the riser's "face". Anything else?
Thanks for all the (very useful) information. I do, however, have one further question:
How do I screed the treads? With forms made like this, the only reference surface I have is the 2 x stock forming the riser. Do I use that only, and screed it level by eye? Or are there any tricks for doing this?
Thanks again,
Alex
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
I used a "mag trowel" between the front riser's top and the back riser's bottom. If the riser forms are laid out right, the tread will be level this way. That is the reason that the riser forms have a bevel along the bottom, you can get all the way to the back of each tread with the trowel. If you really need to check for level, use one of those small "torpedo" levels.
I understand the part about the bevel, but even with that, I am trowelling/screeding using only the riser form in the front, and the deftness of my touch (ha!) in the back. Right?
Alex
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
Yep! One guy I knew would put a "torpedo level" ON his screed board. You can trowel it flat by "eyeball" , spot check it with the level, and trowel some more.
Got it.
I did the form work and rebar today. (I'll post a pic later.) The pour is in a couple of days.
Thanks again to all who gave suggestions and help.
Alex
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx