Steel pipe retaining wall

[flanagaj]

I have a 'retaining' wall to build.  I say 'retaining' as for years it was literally held up with vertically standing paving slabs.  And given it's < 900mm high, I'm not sure how much strength I need to add.  I want something different and am thinking of using the below laid vertically.  It's 2mm wall thickness, but if I fill each tube with concrete, it should suffice,  didn't know if 2mm would be thick enough, if I just wanted to fill with gravel.

 

How long would 2mm steel last before it's eroded through?

 

https://www.ainscoughmetals.co.uk/items/steel-tube/6.100-mtrs-101.6-mm-x--2-mm--steel-tube-!-chs-!-steel-pipe-drainage-!-water-pipe-!-new/17161

Edited September 21 by flanagaj
Added link

[JohnMo]

7 minutes ago, flanagaj said:

How long would 2mm steel last before it's eroded through?

Carbon steel structures normally have a 3mm corrosion allowance.

 

How quick the steel corrodes really depends on how you do corrosion prevention. And how damaging the environment is to the corrosion prevention and then the parent material.

 

Is 2mm suitable? 100mm dia, I would be looking more like 6mm and then hot dip galvanised and not bother with the faff of concrete or gravel. 

[flanagaj]

2 minutes ago, JohnMo said:

Carbon steel structures normally have a 3mm corrosion allowance.

 

How quick the steel corrodes really depends on how you do corrosion prevention. And how damaging the environment is to the corrosion prevention and then the parent material.

 

Is 2mm suitable? 100mm dia, I would be looking more like 6mm and then hot dip galvanised and not bother with the faff of concrete or gravel. 

6mm thickness is very expensive and I want it to have the corten look.  On reflection, 2mm is probably too thin.

Edited September 21 by flanagaj

[Russell griffiths]

On a previous post we found some nice cor ten retaining walls 

you no likey 

[flanagaj]

11 hours ago, Russell griffiths said:

On a previous post we found some nice cor ten retaining walls 

you no likey 

 

Yes, but the moment something is sold as 'Corten' it seems to have an expensive price tag.

[-rick-]

AFAIK Corten is a specific alloy of steel designed to be exposed unprotected. Normal steel will rust and degrade faster than corten.

[Gus Potter]

22 hours ago, flanagaj said:

have a 'retaining' wall to build.  I say 'retaining' as for years it was literally held up with vertically standing paving slabs.

Is the wall near your boundary? This is a key consideration. It's a low retaining wall so you have lots of options if away from the boundary. You'll be surprised how deep you need to knock in tubes to get them to work as the soil contact surface to resist the rotation of the wall is low. 

 

Some basic options and things to consider and rule in or out are; soil terracing with or without careful selection of planting to stabalise the soil, gabion baskets, Universal beams as a king post retaining wall with sleepers, if you have the room in your site then tying the head of the retaining wall back into the soil behind.. basically long rods with a big end plate.. like a tent guy rope but more beafy. You could go masonry reinforced like hollow block or a thicker masonry gravity wall.. but they can be expensive.

 

Post a photo or two so we can see what you have to work with and what you would like to see in terms of appearance / material finish... the look.. cottage garden or contemporary for example. 

[flanagaj]

1 hour ago, Gus Potter said:

Is the wall near your boundary? This is a key consideration. It's a low retaining wall so you have lots of options if away from the boundary. You'll be surprised how deep you need to knock in tubes to get them to work as the soil contact surface to resist the rotation of the wall is low. 

 

Some basic options and things to consider and rule in or out are; soil terracing with or without careful selection of planting to stabalise the soil, gabion baskets, Universal beams as a king post retaining wall with sleepers, if you have the room in your site then tying the head of the retaining wall back into the soil behind.. basically long rods with a big end plate.. like a tent guy rope but more beafy. You could go masonry reinforced like hollow block or a thicker masonry gravity wall.. but they can be expensive.

 

Post a photo or two so we can see what you have to work with and what you would like to see in terms of appearance / material finish... the look.. cottage garden or contemporary for example. 

I cannot have anything thicker than 100mm due to space constraints.  I'll probably just go with RSJ and horizontal sleepers.