Retaining wall

[ash1212002]

Will a concrete gravel board retaining wall setup be suitable to hold back soil that is 3 to 4ft high?

The soil goes back approx 4 to 6 meters

Also is there a risk when it rains that rainwater could seep through between the gravel boards?

Can this be avoided?

Are there any risks with this type of retaining wall?

 

[ash1212002]

I've spoke to a few fencing suppliers who've advised the concrete gravel boards can be used for a retaining wall as they are reinforced

The concrete gravel boards will be 12 inches high and 6ft in length, I'll support the centre of the gravel boards by adding a concrete post in the middle

The retaining wall will be 3ft high approx

I have a few questions regarding what i should place behind the gravel boards, I've seen a few videos online and done some research, I'm thinking of doing the following behind the gravel boards...

Place a damp proof membrane across the length against the gravel boards retaining wall

On the soil side which needs to be retained back, lay down a geo textile membrane across the length

Lay down 5 inch or so 20mm gravel bed across the length of the gravel retaining walls

Lay down land draining pipe

Then backfill with soil

Hopefully it'll look like this

https://ibb.co/Z8kfyFD

Would this be the right approach?

 

[ash1212002]

.

 

[Scarlet Pimpernel]

I wouldn't use gravel boards for a retaining wall of that height.
Even at their own height of about 300mm they don't have much strength over a period of time.
Once they crack, the reinforcing will not prevent them bending and falling out of the posts.

 

[ash1212002]

I wouldn't use gravel boards for a retaining wall of that height.
Even at their own height of about 300mm they don't have much strength over a period of time.
Once they crack, the reinforcing will not prevent them bending and falling out of the posts.

I've spoke to several suppliers who've advised they'll be more than adequate to do the job.

Looking online its not uncommon to do it this way

http://www.shropshiregardendesign.com/shropshire-gravel-board-walls.asp

I've placed the order, just wanted to know what I place behind the boards is correct? And if there is anything else i should do?

 

[^woody^]

The weak point with this type of wall is the post base. They need to be deeper and have a wider concrete surround than for standard fence, and the ground around the base needs to be firm.

You'll need granular stone up the back of the boards, and a polythene barrier else it will look a right mess in a few months time.

 

[ash1212002]

The weak point with this type of wall is the post base. They need to be deeper and have a wider concrete surround than for standard fence, and the ground around the base needs to be firm.

You'll need granular stone up the back of the boards, and a polythene barrier else it will look a right mess in a few months time.

The posts will be going 2ft in the ground, I'll be using postcrete

On the soil side I'll place geo textile membrane

Damp proof membrane on the gravel board side

And in between the above lay 20mm gravel, how much of a depth of gravel should i lay? Before finishing off with topsoil?

 

[ash1212002]

@^woody^ your thoughts?

 

[^woody^]

The weak point with this type of wall is the post base. They need to be deeper and have a wider concrete surround than for standard fence, and the ground around the base needs to be firm.

2 ft might be OK, but might not the OK in soft topsoil. Also, I'd suggest the the concrete surround needs to be wider than that of when just putting fence post in.

Thinking about it, if you put in some gravel for drainage, then you need to drain that at the bottom - via weep holes or a land drain. If the ground is likely to get saturated due to it sloping towards the retaining wall, then a land drain at the base would be something to consider, as weep holes are not possible. However, it may well be that you can just put the polythene membrane up the back of the wall and do away with any gravel.

 

[ash1212002]

2 ft might be OK, but might not the OK in soft topsoil. Also, I'd suggest the the concrete surround needs to be wider than that of when just putting fence post in.

Thinking about it, if you put in some gravel for drainage, then you need to drain that at the bottom - via weep holes or a land drain. If the ground is likely to get saturated due to it sloping towards the retaining wall, then a land drain at the base would be something to consider, as weep holes are not possible. However, it may well be that you can just put the polythene membrane up the back of the wall and do away with any gravel.

The ground is flat and will not slope towards the wall. If that's the case I'll go with just the polythene option and just backfill with soil

 

[ash1212002]

@^woody^ the supplier had initially informed me the 6ft gravel boards had 4 steel rods in them. I've now been told this was a mistake and they have 3

Should I proceed ahead and still purchase given that I'll be using them as a retaining wall @^woody^

 

[AsleepInYorkshire]

Will a concrete gravel board retaining wall setup be suitable to hold back soil that is 3 to 4ft high?

The soil goes back approx 4 to 6 meters

Also is there a risk when it rains that rainwater could seep through between the gravel boards?

Can this be avoided?

Are there any risks with this type of retaining wall?

No. That's a reasonable depth of soil to retain. You need to start thinking of something more appropriate and regretably more expensive. Google Geowall and see if that gives you any ideas or inspiration.

AiY