Making concrete stair treads ?

[Ironwood]

Has anyone ever made concrete stair treads ?

I am wondering if this is an option instead of using timber treads for some stairs I am putting in down at the pool. the stairs will be exposed to the weather, from concrete slab around the pool up onto a raised pergola deck. I would try to make them match the exposed aggregate slab at the pool.

I have ordered a pair of galvanised steel stringers, the treads would need to be about 1200x250x50mm, stringers about 1 meter apart.

I am thinking about using 2 lengths of angle iron with stainless bolts welded for attaching the tread to the stringers, I am thinking about 5 lengths of 1/2" rebar about 1150mm long welded across the tops of the angle, or even drilling holes to pass the rods through the angle pieces and welded to suit the spacing of the stringers.

I am a bit worried if I have allowed enough reinforcing, I can't find any help through google ( maybe I am using the wrong terminology for the search ), maybe someday there will be 2 big fellas carrying a full esky up the stairs......

Am I asking for trouble here, should I just forget it and go back to the timber treads ?

[rod1949]

Lived in Darwin for 20 years. Lots of elevated houses there. In addition to timber stair treads lots of houses had pre-cast concrete treads all on steel stringers. I can't recall ever seeing a hand made concrete treads.

[rwbuild]

12mm reo is too big for the thickness. Min standard cover for reinforcement in an exposed environment is 30mm, in your case, 12+60 = 72 thick tread.
I suggest trench mesh 3TM (3 bare trench mesh) 60mm shorter than the tread, 25mm from the BOTTOM of the tread with a mix of 3:2:2. If its an open riser, make the treads 60mm thick. If you have a hammer drill, use the largest masonry bit you can fit in it and use that against the formwork as a vibrator when you pour your mix, 2 or 3 5-10 second bursts will probably be all it needs, too much vibration and you get separation of your mix.

If you cast bolts onto the tread, DON'T do the bolts up tight, leave about a 1mm play in the nut and put a thick bead of Sikaflex on the angle iron tread support then sit tread on it with some temporary wedges of 2mm to 3mm. The biggest reason for treads failing is uneven uniform support and no allowance for expansion and contraction.

The steel has strength in tension, concrete strength in compression.

[Ironwood]

Thanks for the replies Rod and Ray. I have pretty well given up on making my own. I am worried about the safety of them.
I am going to look at some commercially made treads, otherwise it will be hardwood.

Edit- Ray, that reply was very informative, thanks.

[RoyG]

From my limited understanding, a concrete stair tread, in order to be able to take the bending loads imposed on the stair tread, would need to use pre-stressed concrete construction methods.....

https://en.wikipedia.org/wiki/Prestressed_concrete

[Fuzzie]

Another option would be to use aluminium treads. A bit pricey, but you'll never have to replace one again.
Scott Metals - Products: Aluminium Step Treads: Steel Supplies, Steel Fabrication, Building Products, Steel Products, Stair Stringers, Steel Posts and Beams, Steel Prices, Brisbane Steel Supplies, Brisbane Steel Fabrication, Reinforcing Supplies Bris (http://www.scottmetals.com.au/steptread)

[RoyG]

Ironwood,

Have a talk to Batrosa Concrete Products, at Graeme Heggie St, Outer Harbour, Mackay. Phone: (07) 4955 1000

According to their web site, one of the products that they sell is pre-stressed concrete stair treads....

Your local Masters may also have some - I bought four from Masters Ipswich late last year - about $20.00 each. But, who knows whether they're still available in Master's current condition. Best bet is probably Batrosa.

Regards,

RoyG

[Sam]

Rwbuild is on the money. It's all about cover in your situation.

RoyG - post tensioned/pre-stressed concrete usually is for long spans like bridges and flat plate slabs in car parks, apartment/office buildings or high end mansions. In these flat plate slabs it reduces concrete depth and requires less reo than conventional slabs therefore less labour and less concrete to pour/buy. Generally the minimum length of slab to use post tensioning is about 5 metres.

[chris0375]

There would be no need for post or pre tensioning in this situation.

As mentioned corrosion will be the biggest issue.

You would want the concrete vibrated in very well.

You will struggle to find meaningful reliable and information about reinforcing required online. That's what university is for.

[Ironwood]

Another option would be to use aluminium treads. A bit pricey, but you'll never have to replace one again.
Scott Metals - Products: Aluminium Step Treads: Steel Supplies, Steel Fabrication, Building Products, Steel Products, Stair Stringers, Steel Posts and Beams, Steel Prices, Brisbane Steel Supplies, Brisbane Steel Fabrication, Reinforcing Supplies Bris (http://www.scottmetals.com.au/steptread)

Cheers Fuzzie. I think those prices are not too bad. I worry how hot they would get in summer, bare feet running up and down might not be too pleasant.
I found one of the local scrap metal dealers has some aluminium step treads, still attached to some rusty looking stringers, they weren't much cheaper than those in your link.

[Ironwood]

Ironwood,

Have a talk to Batrosa Concrete Products, at Graeme Heggie St, Outer Harbour, Mackay. Phone: (07) 4955 1000

According to their web site, one of the products that they sell is pre-stressed concrete stair treads....

Your local Masters may also have some - I bought four from Masters Ipswich late last year - about $20.00 each. But, who knows whether they're still available in Master's current condition. Best bet is probably Batrosa.

Regards,

RoyG
Thanks for that Roy. I will check them out.
There are a couple of other places down at the harbour that sell concrete products, pavers and retaining wall blocks etc. I will take a drive down there one day and check them all out.

I have looked on the Bunnings and Masters websites, they both sell them, but the websites said they were special order. From memory the Bunnings ones were over $100 each.

[Ironwood]

I have the stringers being freighted up here, should get them Friday I hope. When I get these I can finish off the deck structure to suit where they will bolt on. I know I am going 1200mm step treads, but I will leave the spacing of the stringers until I have the treads in my hands.
I have a couple of weeks until I get to the stage of needing the treads, so plenty of time to explore options.

If I end up going hardwood, I will get them off the Eungella sawmill, his pricing is always good, and he delivers down this way. I could cut them out of some of my slabs, but it would waste a lot of timber.

[Fuzzie]

Cheers Fuzzie. I think those prices are not too bad. I worry how hot they would get in summer, bare feet running up and down might not be too pleasant.
I found one of the local scrap metal dealers has some aluminium step treads, still attached to some rusty looking stringers, they weren't much cheaper than those in your link.

Our pool steps down here are aluminium and get the full west sun. The steps are cooler in summer than the brick paving they lead to. I guess it is due to the light colour and thinnish cross section that air cools freely.

[Ironwood]

Our pool steps down here are aluminium and get the full west sun. The steps are cooler in summer than the brick paving they lead to. I guess it is due to the light colour and thinnish cross section that air cools freely.

That sounds reassuring Fuzzie. I will definitely keep the aluminium treads open as an option.

[Ironwood]

I rang Ullrich Aluminium in Mackay, They sell the aluminium extrusion for step treads in 6005mm lengths for $131, they sell the endcaps separately , I forgot to get a price on these.
Looks like this will work out quite economically going this way, I just have to cut them myself. I have cut smaller aluminium extrusions before with my Makita SCMS, it should handle this if I go steady. Though I will get a price for them to cut them, if its reasonable I will get them to do it.
I will end up with a 3600mm offcut, but I have a use for this.

I rang Batrosa today but just kept getting their answering machine, rang a couple of other local places re concrete treads, no luck.

The stringers turned up today, need to do some more structural work to the deck before I can bolt them on.

[Enfield Guy]

I installed a 16 tread set of stairs at my girlfriends place a while ago. Full summer sun from 10am till pretty much sundown. They tend to be cooler to walk on than the timber treads at the front of the house which receive far less sun. Go the ally, you won't look back.