Repair to foundations of wall adjacent stream

[steph501]

I have a concrete block wall next to a stream. I have filled some cracks with Cementone waterproof cement and made a good fix. The foundations have been affected by crayfish burrowing at the bottom and I think this is why there is cracking on the wall.

I need to do something to fill in under the wall where the crayfish have burrowed and was thinking of filling sandbags with a mix of the cementone waterproof cement and sand but the packaging doesn't say you can mix it into a mortar consistency. Does anyone know it this would be O.k and any other ideas of how to strengthen the foundations in running water?

Thanks for any help

 

[bernardgreen]

I had to create a retaining wall to stop erosion where my garden met a stream.

I dug about 12 inches down into the stream bed and laid in sandbags filled with a basic concrete mix using ordinary Portland cement. From memory there were six courses to come over the water line. Metal stakes spaced two metre apart were driven vertically through the bags.

Stamp the bags into place as they are laid, Have them filledwith dry mix ready to lay as soon as the trench is dug. Do not over fill them. Fill them so that when laid flat there is large contact area between them

That was 25 years ago and the wall later built on them is still standing firm despite several flash floods and high velocity spate flows

 

[steph501]

Thanks for your reply Bernard - unfortunately, there isn't any space available to build another wall, but your method is the way to go about it. Just been speaking with someone at Bostik who recommended mixing cementone rapid hardener and plugger liquid with portland cement to a mortar like consistency , this mixture then changes quickly to a putty/plastacine mixture who is very strong and can be plugged into the gaps with your hands using heavy duty gloves. Might try this and see how it goes.

 

[Beefpotnoodle]

How big is the stream?

 

[Beefpotnoodle]

Oh, and are the footings exposed stream side?