Browse Forums Landscape & Garden Design 1 Feb 15, 2009 1:54 pm Like many other people out there, the long hot summer has taken an effect on my garden. Unfortunately, there hase been some recent movement (ie drying out) of the soil of a retaining wall in my front yard.
Is there any way I can get the soil to move back to its original position through selective watering ? ie if I focus my watering on a certain area in comparison to other areas, can I get the gaps in the brickwork to close in again ? The photos best illustrate. I guess the question really is, should I be watering more a) the grass at the base of the wall or b) the plants inside the retaining wall ? many thanks for your advice ! Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Why are priates scary ? Because they yaargh.. Re: Help save my retaining wall ! 2Feb 15, 2009 7:33 pm do you have aggy drains behind wall? if not the drought has nothing to do with your wall failing the soil behind the wall is slowly compacting and is pushing the wall over
is the wall on a rock base, if so then the wall is doing what it is supossed to do , fail no wall will stay up if it is on a rock base link block manufacturers recommend there walls be built on rock for the diy but what they dont tell you is the draw backs of negative hydrostatic pressure, back fill compaction etc should be on a reinforced concrete footing Da Vinci Outdoor Living Architectural landscaping http://www.davincioutdoor.com Re: Help save my retaining wall ! 3Feb 15, 2009 9:31 pm The soil when it drys shrinks. That is just what it does.
Now when you rewet the soil it doesn't just rewet. It will take more water than you think and much longer to get the soil to expand back to what it was. As an example on a smaller scale, You have a pot that has dried. You water it and it looks wet. take it out of the pot and you may see that the water only went on the top and some way down the sides. A fair bit will go straight through. You water again and remove from the pot. Water will have moved further down the sides but there will still be very dry spaces. The water moves as it wants. Still high run off will happen. It still isn't wet I can assure you. Even after a 3rd watering you can remove it from the pot and if you sacrifice a plant and pull apart the root ball it will be bone dry in the centre still. It can take 5-7 waterings to properly rewet the root space right through. Now what also happens is the fine feeder roots will have been badly damaged as they do when they go dry. It is going to take around 4 weeks for them to recover and be able to absorb water and nutrients sort of properly again. They too will expand and take up soil space. (That is one reason why you don't fertilise in the heat or with dry soil but i digress) Over all it may take a very long time on a bigger scale to get that raised bed back to ideal. many many many short waterings. short because you make better use of water by reducing run off. Your hose will always apply more water at a rate than the soil can absorb. Something that not many know and I can go into that more too Lots of little waterings, evenly applied each day over several weeks. Don't forget the seasol, your plants feeder roots will love you Blend that with davincis info, Oh and water the plants, the water run off will find it's way down to the turf and lower parts of the wall footings just fine. Re: Help save my retaining wall ! 4Feb 15, 2009 9:52 pm These were done to demonstrate about how watering should be done, what happens when plants dry out, and how to properly rewet a plants roots space in a pot (yours is the same but on a bigger scale.
(Here we used plants from my mates nursery, Hope Valley Nursery which do the highest quality potted colour in WA Keep an eye out for it in your local retail nursery.) after a longish water and first look... Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ after a few more waterings and another lookie... Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ and after a few more waterings it still had not absorbed the water effectively through to the centre of the pot. The run off was huge. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Help save my retaining wall ! 5Feb 16, 2009 12:39 pm thanks for the info guys.
The wall was put in by a landscaper. From memory, it has a quarry rubble base and is a dry wall. It was originally sloped back somewhat to lean against the raised bed. I asked him if he thought a wet wall would have been appropriate, but he didnt think so. Davinci, if I read you correctly, what has happened is that the soil has compacted at the bottom (gone "pear shaped", so to speak) and is pushing the soil out ? I found it interesting to read that you should put these walls on a base of concrete. the gross majority of online sites talk about using a 20 - 30mm base of quarry rubble. When you say "base of concrete" do you mean pouring it in and setting the first course while the concrete is still wet, or getting the levels right and putting it on top of concrete that has dried ? FuManch, thansk for the advice. Ive been improvising with a hose dripper over the past few days that hopefulyl will bring it back. The plants in the wall are fed by dripper system. I suspect that this may have been part of the problem - too much localised watering, as there arent that many plants in the garden bed ? Thanks again guys. Why are priates scary ? Because they yaargh.. Re: Help save my retaining wall ! 6Feb 16, 2009 6:10 pm do away with individual drippers, they'll never be effective methods of watering. Convert your drippers to using Netafim or Netascape driplines. These have drippers built in every 30cm with in the tube. Make sure you bung on a filter with a water pressure reducer, a flush valve and air bleed valve. each valve cost about $10. the filter and reducer will cost about $15 for something basic and a better one about $30 and the dripline will be around the $50 mark for a roll, sometimes more for longer lengths.
I can't stress enough that these products must be purchaced from irrigation shops as other places selling these systems have a serious lack of understanding of them, have serious lack of qualified irrigation know how and do not carry all the components to walk away from them with everything you need Don't by drip line that looks like a snake that has swallowed a mouse. Get the one that has a smooth surface. Netascape or techline AS. Even waterwise watering will result as well as reducing compaction and increasing root mass. Re: Help save my retaining wall ! 7Feb 17, 2009 9:03 am I just thought I would mention, this is a curved wall and these are weaker than the straight ones and having it dry was not such a good idea . Another reason for it moving is the top is too wet due to drip irrigation and the lower part lawn too dry. It is just logical thinking not being an expert. I do hope it can be rectified as repairing it would be a big job. Can yopu get back the original landscaper and ask him to fix it, free of charge of course???
Maggie Thank you again Simeon.. I will call my certifier for that. Have a good day 4 5197 I've just had a look at the website. The company are just building broker's. There are plenty of similar companies that basically draw your plans (they own them so you… 8 10944 Thanks for your reply! All valid points and I agree with you on many of them. I am in QLD, any recommendations on a construction lawyer would be helpful 3 2649 |