Suspended Concrete Entry Stairs

[HoosierBuddy]

Hey guys,

For 2 years, I've been trying to get a contractor to replace the treated wood stairs going into our home's kitchen door exterior door with concrete.

3 different contractors have come out and looked at it...said they'd do it....then ghosted me. The problem is it's pretty complicated for a small job. The amount of concrete required is small but the whole job is fiddly....meaning a lot of things could go wrong and at the end of it....probably not a lot of money to be made.

So....I've decided to do it myself. Got on the youtube. Watched a bunch of videos on how to form stairs. I came to the conclusion that this is NOT the right project to be the first concrete I've ever formed in my life.

So....I came up with a different plan to utilize the skillz I have and the tools I have to design something I can build myself. Basically, I've ordered (from a company that does precast concrete work, 3 precast (reinforced) 12 X 48 stair treads and 1 precast 4 foot square landing. These are the same sort you might run into at an apartment building.

My plan is to demo my old porch, excavate and pour a footer (I think I can handle that) then build a structure above that with 4" Square 1/4" Wall structural tubing to carry the slab. The risers will be built out of the same tubing with the treads carried from the back with 4" X 2" tubing to make them sort of "float".

The precast concrete includes cast in weld plates. I'm planning on using those to secure the concrete to the steel structure.

I'm a little uncertain about how to tie in my railing. For right now I'm thinking I'll drill all the way through the concrete for 4 bolts per post, and use a drilled steel plate underneath (instead of 4 washers) with bolts/nuts.

Anyway....I think it will look pretty decent when done. Anyone have any thoughts?

My drawing is below.

Phil

 

[matt_i]

Seems like a good plan, but with the steel, you're going to have to paint it with something durable. Im far from an expert, but the little I've done leads me to believe something like a 2K primer and a 2K top-coat so you don't have to prep & re-paint the underside every couple of years (that would irritate me).

Also I'd work on how to rig a 48 x 48 x 4 concrete slab into place. Rough numbers are right around 800 lbs.

If you have control of the railing I think I'd lay it out after the stairs are all placed and finalized. Then drill a single oversized hole and thru-bolt from the underside. Tapped plate inside the bottom of the post. Seems like 4 drilled holes close together could lead to cracking between the holes.

 

[fourbyford]

I agree with Matt's comment about cracking... I would also be concerned with the steel mounting plate (and bolts) sitting in water/snow/ice.

Instead of bolting a plate to the top of a step, is there a way to attach from underneath... or to the steel stringers?

...D

 

[TommyK]

Can't you just get a set of precast concrete stairs?

 

[strutaeng]

Sounds like a reasonable plan. Can you instead just form the entire stairs, fill and compact, and pour a solid concrete? I think that's how they are done around here.

Should require no real maintenance for at least 50 years.

 

[bigguns69]

Picture looks good. The precast steps are a good alternate, buy, put in place.

https://www.google.com/search?rlz=1...gQICxAB&biw=2560&bih=1297&safe=active&ssui=on

 

[HoosierBuddy]

Thanks guys,

On the painting comments....agree completely. Obviously with this setup I will never be able to put salt on my stairs. The good news is, there is another set of stairs 10 feet away from these inside the garage, that lead the same level of the kitchen. The wall I show as an endview in my plans is the wall the the heated 3 car garage....meaning we don't have to use these stairs if it's icy or snowy.

I will definitely be priming them and painting them with the best system I can come up with.

Regarding precast steps....this same place I'm getting my treads and deck cast at can make those as well. I don't like the looks as much as what I've come up with myself. Also, the steel has all been purchased and the order placed for the concrete, so this project is moving ahead at this point.

Thanks for pointing out the issue with cracking between bolt holes. I will rethink that....and yes there may well be a way to drill a larger hole that would allow me to attach something directly to the steel underneath, come through the tread and support the posts.

For rigging, I'll have to borrow a tractor or backhoe and set it using the front loader. My work lets us borrow equipment for weekend use. One of the nice perks that I rarely use....but when you need a backhoe for a Saturday is VERY nice to be able to do that.

Phil

 

[TLCObsession]

I did a flight of 11 steps using precast treads. I used the brackets they came with and bolted to PT 4 x 12's stringers. I landed them on some precast 2 x 2 pavers. They are supported mid span by a post going into a footer. Used some high density plastic on the bottom of the stringers where they touch the pavers. Really worked out well and the homeowners is pleased.

I will say I should not have loaded the treads in my pickup - Steering was a little light on the ride home!

 

[danski0224]

Pretty sure that type of stair in a commercial setting is a steel framework with a pan for each tread that is then filled with concrete. The railing is part of the steel frame, concrete is poured around it.

You need to make a steel wrap on the sides, a channel that the tread slides into, that the railing can be welded to.

 

[Milton Shaw]

I went with steel stair pans that were welded to channel for the stair stringers and then filled with concrete for the three sets of steel steps I have made. I did put a couple of pieces of rebar in each step before I poured the concrete and so far have not had any problems with them. I did use channel iron for the stair stringers instead of the formed steel risers as they have a lot more steel in them. After 10 years or so they do need painting but have not gotten around to that yet. Triple S Steel is where I sourced the steel. As I remember each step took just about a bag of concrete, so it is an easy project to space out for your time and energy level, instead of having a whole truck of steel to handle.