Outdoor stairs thickness

Forums › Home Workshop DIY › Outdoor stairs thickness

xpd

Geek of Coastguard
14115 posts

Uber Geek
+1 received by user: 4574

Retired Mod

ID Verified

Trusted

Lifetime subscriber

#302399 20-Nov-2022 15:47

Need to replace some outdoor stairs, but can't seem to find what thickness the timber should be these days. I know its 900mm wide and treated pine but thats it :) I can measure existing stairs, but the way this place was built, I highly doubt they were correct thickness (bloody home handymen who think theyre gods gift to housing), so would like to do it right.

Anyone point me in the right direction ? :D Wife did ask at Mitre10 but they were useless.

XPD / Gavin

LinkTree

richms

29097 posts

Uber Geek
+1 received by user: 10206

Trusted

Lifetime subscriber

#2998817 20-Nov-2022 16:02

Without a picture of these steps this is pretty hard to answer.

Richard rich.ms

eracode

Smpl Mnmlst
9332 posts

Uber Geek
+1 received by user: 6198

ID Verified

Trusted

Lifetime subscriber

#2998818 20-Nov-2022 16:09

Why do you need to replace them? Because they’re not thick enough - how thick are they?

Generally steps that are 900 mm wide would be 45/50 mm thick if made from treated pine but it depends on the specific situation - photo would be good, as commented above.

Sometimes I just sit and think. Other times I just sit.

djtOtago

1181 posts

Uber Geek
+1 received by user: 605

#2998819 20-Nov-2022 16:13

Bunnings do outdoor stairs kitsets
Maybe take a look at how there do it

xpd

Geek of Coastguard
14115 posts

Uber Geek
+1 received by user: 4574

Retired Mod

ID Verified

Trusted

Lifetime subscriber

#2998825 20-Nov-2022 16:55

The bunnings kit are expensive :)

And yes, 900x300x40 seems to be the "norm" after some digging around. But finding someone who can supply that, seems to be a mission :) I do know someone in the staircase business but hes down and out with COVID :(

I'm replacing them because they're probably 30+ years old, and some are about to break (Already had one break as I stood on it) :) Not doing it for fun :D

XPD / Gavin

LinkTree

eracode

Smpl Mnmlst
9332 posts

Uber Geek
+1 received by user: 6198

ID Verified

Trusted

Lifetime subscriber

#2998829 20-Nov-2022 17:07

xpd:

The bunnings kit are expensive :)

And yes, 900x300x40 seems to be the "norm" after some digging around. But finding someone who can supply that, seems to be a mission :) I do know someone in the staircase business but hes down and out with COVID :(

I'm replacing them because they're probably 30+ years old, and some are about to break (Already had one break as I stood on it) :) Not doing it for fun :D

Treated pine (you would need C3 grade) dressed from 300x50 ends up being 295x45 and is pretty much standard for most outdoor steps. It’s commonly available from timber merchants and from Bunnings/M10/Placemakers - nothing unusual about it.

Sometimes I just sit and think. Other times I just sit.

eracode

Smpl Mnmlst
9332 posts

Uber Geek
+1 received by user: 6198

ID Verified

Trusted

Lifetime subscriber

#2998839 20-Nov-2022 17:31

Stairs can be ‘open’ or ‘closed’. The horizontal part is the tread and, if closed, the vertical part is called the riser. Closed steps are stronger (less bendy) than open because the riser supports the underside of the tread and transfers some of the weight on the tread down to the tread below. The top of the riser is fixed to the front underside of the higher tread - and the bottom of the riser is fixed to the back edge of the lower tread. That means two treads are sharing the weight on any given tread.

These are some very bendy semi-open steps I rebuilt as solid closed steps for a friend a few years ago - photos might help explain what I’m getting at. The treads are dressed 300x50 C3 pine and the risers are dressed 150x20 C3. There is a 5mm gap built into the join between the back of each tread and the lower face of the riser, so that any water that wants to accumulate on the tread can get away.

Sometimes I just sit and think. Other times I just sit.

Mighty Ape

Shop now at Mighty Ape (affiliate link).

xpd

Geek of Coastguard
14115 posts

Uber Geek
+1 received by user: 4574

Retired Mod

ID Verified

Trusted

Lifetime subscriber

#2998848 20-Nov-2022 18:15

Cheers @eracode

Current ones are "open" but looking to swap out to "closed", will see what the wife thinks ;)

Looked on M10 and Bunnings sites, and they dont have anything listed, guess its one of those things got to go see for myself :)

Thanks all

Will update as I go :D

XPD / Gavin

LinkTree

eracode

Smpl Mnmlst
9332 posts

Uber Geek
+1 received by user: 6198

ID Verified

Trusted

Lifetime subscriber

#2998850 20-Nov-2022 18:22

If you’re only replacing the treads (and maybe adding risers) - and retaining/re-using the existing stringers (diagonal side pieces), I really doubt that you would need a kit. A kit will likely include stringers and you may be paying for something you don’t need - and also making it a far more complicated job. You would effectively be starting from scratch.

For the job in the photos, you can see I kept the existing stringers and that meant it was actually fairly simple.

Sometimes I just sit and think. Other times I just sit.

neb

11294 posts

Uber Geek
+1 received by user: 10018

Trusted

Lifetime subscriber

#2998862 20-Nov-2022 19:02

xpd:
Current ones are "open" but looking to swap out to "closed", will see what the wife thinks ;)

One consideration for open vs. closed, if they're in an area that collects rain/moisture you probably want to go with open risers otherwise you're trapping a lot of damp under there, unless there's some other source of air circulation present.

wellygary

8810 posts

Uber Geek
+1 received by user: 5287

#2999059 21-Nov-2022 10:06

neb:
xpd:

Current ones are "open" but looking to swap out to "closed", will see what the wife thinks ;)

One consideration for open vs. closed, if they're in an area that collects rain/moisture you probably want to go with open risers otherwise you're trapping a lot of damp under there, unless there's some other source of air circulation present.

Or, you leave a slight (10mm) gap on just the lowest step to allow water egress and airflow...

openmedia

3449 posts

Uber Geek
+1 received by user: 877

Trusted

#2999133 21-Nov-2022 11:46

This is the sort of thing you can use

You can use off the shelf H3.2 timber for the treads if you want, but make sure you meet the building code on footings

Generally known online as OpenMedia, now working for Red Hat APAC as a Technology Evangelist and Portfolio Architect. Still playing with MythTV and digital media on the side.

Geekzone

Want to support Geekzone and browse the site without the ads? Subscribe to Geekzone now (monthly, annual and lifetime options).

eracode

Smpl Mnmlst
9332 posts

Uber Geek
+1 received by user: 6198

ID Verified

Trusted

Lifetime subscriber

#2999148 21-Nov-2022 12:46

openmedia:

You can use off the shelf H3.2 timber for the treads if you want, but make sure you meet the building code on footings

When I said ‘C3’ treated pine in earlier posts, I knew that didn’t sound quite right - and it wasn’t. Meant to say H3.

Sometimes I just sit and think. Other times I just sit.