Gabions. DIY in galvanised mesh or HD plastic ??

sarabande

sarabande

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I have - possibly a need for a retaining wall, and the DIY route appeals.

Any views, advice and experiences welcome

Ta !


(I have some minor revetment experience with Netlon, which is positive.)
 
No experience with HD plastic but used and built or people working for me build gabions using the traditional galvanised cages which are I expect still doing their job many years after being made. Unless you have the lifting kit to place them suggest that you construct them in situe obvious but... Also use good stone of caring sizes to ensure good packing density.
 
The choice will depend on how much acidity and free radicals are in the groundwater, in other words how corrosive it is. If the groundwater is relatively corrosion free then galvanised would be better, if it's corrosive the galvanising will dissolve away quite quickly leaving the steel unprotected in turn, in which case plastic coated would be better. I wonder if they make them in stainless? Cost a fortune if the exist.
 
RichardS said:
Gabions. A word I've never heard before so I've no idea what it means.

However, I'm guessing that they are Practical and that they have an Owner.

It's the connection with Boat that I'm struggling with. ;)

Richard
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He's building his own harbour, perhaps. ;)

I'd say this was the most likely forum to catch the eye go those with, er, practical knowledge of, and interest in, the project.
 
I think the caution re acidity in post 3 is worth heeding, around here we are in a peaty environment, acidic soil and groundwater, they tried gabion cages in place of the stone pitching along the canal edges, did not seem to last too long.
 
RichardS said:
Gabions. A word I've never heard before so I've no idea what it means.[...]
It's the connection with Boat that I'm struggling with. ;)

Richard
Click to expand...

My word; a whole life lived without coming across "gabion". I would feel I have achieved something if you were to look it up.

And yes, boaty. Definitely. As part of a revetment (q.v. ) they would stop a cliff falling on my dinghies. Rather like raindrops on my head.
 
Quandary said:
I think the caution re acidity in post 3 is worth heeding, around here we are in a peaty environment, acidic soil and groundwater, they tried gabion cages in place of the stone pitching along the canal edges, did not seem to last too long.
Click to expand...

I was looking into buying a reservoir requiring remedial work on the dam, subject to statutory surveys Reservoirs Act 1975 etc. Gabions were the solution but the water was very acidic from surrounding conifer forests.
 
When the plastic cages first came in they were found to be susceptible to fire. I don't know if they have now addressed this.
 
SAPurdie said:
The whole concept has always worried me. Couldn't one just throw mortar or concrete in as well. Then it wouldn't matter if the container failed in time as the concrete would have hardened by the time it did?
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I think there are several issues with what you suggest;

1) Concrete is impermeable, and a gabion is usually intended to be pervious.
2) Concrete leachate is bad for the environment.
3) Concrete is (relatively) expensive.

None are show-stoppers, but may explain why gabions are preferred to concrete in many applications.
 
As a retaining wall you need two things:

Weight concentrated at the foot of the embankment and keyed into the ground, gab ions provide this.

Permeability to avoid hydrostatic pressure building up behind the "wall" again gabions provide this by mixing in concrete or mortar you will reduce the permeability considerably and end up with the gabions creeping forwards. I have actually seen this.
Gabions are a cheap (relatively) way of providing a retaining wall with little preparation, to do it with concrete requires significant excavation for foundations and the issue of hydrostatic pressure needs to be addressed usually by placing a layer of permeable material behind the wall and then providing holes in the concrete wall for drainage. A structural engineer would no doubt go into much more detail but in small scale works the above is a practical solution.
 
What is the plastic?
In the long run, I'd be concerned about UV stability.
Or other shades of biodegradability.
ISTM that gabions are not always considered permanent.
 
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