Retaining wall with Whites Retain It system

Hello, sorry if I am posting duplicated subjects. Had a look but didn't find answers directly relevant to my project, so I hope you don't mind posting this here.

I would like to build a retaining wall using the Whites "Retain It" system. The wall would be about 8.5m in length. I plan on using Ironwood 200 x 75mm 2.4m Sienna treated pine sleepers. I am planning of a height three sleepers (about 600mm). I would also like to install a capping on top of the wall. It will be more of a garden wall than a retaining wall. I am planning to use whites 1500mmx75mm posts.

I'm aiming for a straight line version of:

Screen Shot 2021-05-17 at 10.55.55.png

My questions to begin with:

What should the distance between the Retain iT posts be for 75mm sleepers? Can the full length of 2.4m be used?
If the sleepers need to be cut to length, do they need to be treated in some way to maintain protection agains decay and so on?
What is generally used for the top capping? Would it be another sleeper? How should the capping be fixed to the wall sleepers?
How much quick set concrete should I plan for each of the joiner posts?

Thanks in advance for any advice.

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Comments

MitchellMc

Welcome to the Bunnings Workshop community @steveof2620. It's wonderful that you've joined us, and many thanks for your questions.

For a retaining wall that needs engineering, there might be a stipulation on maximum post spacing. If the height of 600mm means you are not required to have the wall engineered in your state, then a span of 2400mm between posts is suitable.

If you need to cut sleepers to length, you can reseal their ends with TWA Woodcare 300g Ecoseal Tanalised Timber Treatment.

The top capping can be constructed from a sleeper, and Buildex 16-8 x 125mm Climacoat Type 17 Timber Construction Screws would be sufficient to hold them in place. You would screw directly through the capping and into the edge of the sleeper below. Try to offset your screws instead of running them all in a straight line, as per the image below. This will give the capping more rigidity. You might find that using a full-width sleeper makes the capping slightly disproportionate to the rest of the wall. You could either rip it down the length to make it slightly thinner or choose to use a 50mm thick version instead.

Whites recommends that you have around as much post in the ground as out of the ground, so in your case, the Whites Outdoor 1100 x 75mm Retain-iT Joiner Post should be adequate. You'll need a hole at least 300 x 300mm wide and the depth of your post. 40kg of concrete fills a 300 x 300 x 300mm cube. If you were to use the 1100mm joiner, that would require around four Bastion 20kg Rapid Set Concrete bags per post.

I look forward to following along with your project. Please let me know if you have more questions.

Mitchell

steveof2620

https://www.workshop.bunnings.com.au/discussion/comment/13405#Comment_13405

Awesome, thanks very much for your replay. That information is most useful. Thanks for taking the time to respond. Cheers.

steveof2620

https://www.workshop.bunnings.com.au/discussion/comment/13405#Comment_13405

Hi,

Thanks again for the information you provided.

Couple of queries:

I noticed the cement you mentioned is not available at stores close to me. I thought I'd order the Australian Builders 20kg Quick Set Concrete instead. I assume that would be a suitable replacement.

In terms of digging the holes for the posts, I thought I'd purchase a Spear & Jackson Long Handle Post Hole Pincer for that job.

Does that sound OK or do you have other suggestions?

Also do I need some sort of drainage gravel to place under the bottom sleepers?

Thanks again.

StevieB

https://www.workshop.bunnings.com.au/discussion/comment/69228#Comment_69228

Hi @steveof2620,

Fantastic to see that you’ve already received helpful advice from @MitchellMc. He’ll be more than happy to help further when he’s back on the site on Friday.

Stevie

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/69228#Comment_69228

Hi @steveof2620,

Australian Builders 20kg Quick Set Concrete is most certainly a suitable alternative. The post hole digger will make easy work of digging soil. If the ground is rocky, you might like to have a mattock on hand as well.

No drainage gravel is needed under the sleepers, but you might like to read through @Adam_W's step-by-step article on How to build a retaining wall. In step eight he shows how to lay an agricultural line behind the wall to remove excess water and divert it away from the wall.

Please let me know if you have more questions.

Mitchell

steveof2620

https://www.workshop.bunnings.com.au/discussion/comment/97609#Comment_97609

Thanks again for your advice. Very helpful.

Adam_W

https://www.workshop.bunnings.com.au/discussion/comment/115482#Comment_115482

Sounds like you're on the right track now @steveof2620 one comment however...
If the wall is retaining any material at that height it may need engineering approval. Different councils have differing rules I believe but generally anything over 400mm likley needs some sort of design input as a minimum as you need to get deep and width of footing right to avoid failure.

steveof2620

https://www.workshop.bunnings.com.au/discussion/comment/13405#Comment_13405

Hello,

I received my delivery of Ironwood 200 x 75mm 2.4m Sienna Treated Pine Sleepers, but they do not appear stained as illustrated. If anything, they are beige with a green hue. I am wondering if these can be stained and if so what stain would be recommended. I'd be looking for something that would stain the sleepers into a colour like that depicted on the website (see below).

Screen Shot 2021-06-23 at 08.26.26.png

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/69478#Comment_69478

Hi @steveof2620,

Typically, because of the treatment of Sienna sleepers, they have a red-coloured hue. I'll reach out via private message to get your location details so I can investigate further.

The sleepers can be stained, but I'd like to double-check your order to make sure that you've received the correct product.

Mitchell

Boooooort

https://www.workshop.bunnings.com.au/discussion/comment/97767#Comment_97767

Hi Mitchell,

could I build an above ground pond (for fish) with this sort of set up, and line it internally with pond liner?

im thinking about 1800 x 800 x 600 high?

would I need then 600mm hole for posts?

Jason

https://www.workshop.bunnings.com.au/discussion/comment/115573#Comment_115573

Hi @Boooooort,

Thanks for joining in the discussion and welcome to the Bunnings Workshop community. We're so pleased to have you join us and look forward to reading about all your projects and plans for around the house and garden.

Mitch is taking a well-earned break at the moment, so I will ask @EricL to assist you when he is back on the site tomorrow. Let me also tag @Adam_W to see if he can share his expertise.

Please don't hesitate to post anytime you have something to share with the community or need a hand with a project. We're sure you will get plenty of helpful information, advice and inspiration from our clever and creative community members.

Jason

Boooooort

https://www.workshop.bunnings.com.au/discussion/comment/125686#Comment_125686

Thanks @Jason !

EricL

https://www.workshop.bunnings.com.au/discussion/comment/132470#Comment_132470

Hello @Boooooort

Thank you for sharing your query about the Whites Retain It system as a possible framework for an above-ground fish pond. If you are using it as a pond enclosure and not a retaining wall you probably don't need such large footing. A post hole of 300mm would be enough to keep the post stable. I would follow the rules for depth and that half of the post must be underground to prevent any shifting.

Please make sure that there are no sharp objects at the bottom and sides of the enclosure when you install your pond liner.

Let me call on experienced member @Adam_W for some advice.

Please keep us updated, we look forward to the start of your build.

Eric

steveof2620

https://www.workshop.bunnings.com.au/discussion/comment/136618#Comment_136618

I have installed my retaining wall and am quite pleased with the result.

The next step is to install an irrigation line and electrical conduite behind it before I back fill. Also intend to add some decking oil to darken the colour a bit.

Thanks to all those who provided me with advice and support I needed to complete this project. The feedback you provided is greatly appreciated. You guys rock.

*** Tried to upload an image but the system won't allow me to add one, something about invalid HTML ***

As in..

Correct the highlighted errors and try again.
Your post has been changed because invalid HTML was found in the message body. The invalid HTML has been removed. Please review the message and submit the message when you are satisfied.

Jason

https://www.workshop.bunnings.com.au/discussion/comment/139482#Comment_139482

Thanks for the update @steveof2620.

It would be great to see a photo of what you've done.

You might get that error message if you have cut and pasted something from another source (which comes with hidden HTML tags). Just hit the post button after you get the message and you should be fine.

If you have further dramas, feel free to email the photo to workshop@bunnings.com.au and we can add it for you.

Thanks again,

Jason

Adam_W

https://www.workshop.bunnings.com.au/discussion/comment/115573#Comment_115573

Hi @Boooooort & apologies for the delay. We've had our Queensland Garden Expo on up here so busy time for me.
You can line a structure with flexible pond liner to create a pond but... you do have to bear in mind that the wall then becomes load-bearing as it is 'retaining' the weight of the water. Water weighs 1tonne per cubic metre so your proposed size would be retaining around 800kg of water plus any rocks etc. you add in a 'static' load.
This means you'd definitely want post holes around that 500mm depth and width... depends a little on your soil but you'd want at least 100mm of concrete front & rear of the post.
I'd also recommend using a high MPa concrete mix.

That sort of answered your questions?

steveof2620

https://www.workshop.bunnings.com.au/discussion/comment/141404#Comment_141404

OK, here it is in all its glory.. Thanks to everyone who replied with tips and advice. And yes, its level!

IMG_0604 copy.jpg

EricL

https://www.workshop.bunnings.com.au/discussion/comment/142848#Comment_142848

Hello @steveof2620

Thank you for sharing your retaining wall project. It looks fantastic! What stain did you use to colour it? Did it take very long to build? I'm sure our members would love to hear the details of your build.

We look forward to seeing more.

Eric

steveof2620

https://www.workshop.bunnings.com.au/discussion/comment/143861#Comment_143861

It was a pretty straight forward build in the end. I did it over a few weekends, someone with experience would be able to do it over a single weekend I reckon. The colour is the colour of the Sienna Treated Pine Sleeper I obtained from Bunnings. The colour is growing on me but I think I'll apply some decking oil to darken the colour a bit.

Boooooort

https://www.workshop.bunnings.com.au/discussion/comment/125715#Comment_125715

Thanks @Adam_W Yes it does. I might need to check first where digging the posts as it runs close to a sewer line I think. How much concrete would I need for each post? I figure you mean about .2m x .2m x .5m x 4 posts? Ie about 20L per hole?

EricL

https://www.workshop.bunnings.com.au/discussion/comment/132498#Comment_132498

Hi @Boooooort

Thank you for the update on your proposed pond. Let me tag @Adam_W so they're made aware of your question. Looking at Adam_W's recommendation, I read it as 500mm wide in diameter and 500mm deep for each post. It's recommended to be built that way to hold both the retaining wall and the water in your raised pond. Using a standard 20kg bag as our reference, you would approximately need 11 bags per post hole.

I agree with Adam_W's recommendation of high MPA-rated concrete. This type of concrete is at least twice as hard as regular concrete. If you would like to tell me your closest store, I can inquire for you to find out what they have in stock and have some put aside.

If you need more advice or information, please let us know.

Eric

tabbas_diy

Hi there,

I've done nearly the exact same timber retaining wall at my house. Just wondering what colour code he used for the lacquer when he painted the sleepers.

Please help with the colour/paint, lacquer used in the photo above.

Much Appreciated,

Tom.

EricL

Hi @tabbas_diy

Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thank you for sharing your question about the finish used on the sleepers.

Let me tag @steveof2620 to make them aware of your question. If I recall correctly, they stayed with the Ironwood 200 x 75mm 2.4m Sienna treated pine sleepers finish. It was only later on that they decided to oil the surface, but they did not mention what they would use.

However, looking at the picture posted, it might be close to the Feast Watson 4L Natural Traditional Timber Oil. Timber being a natural product often reacts differently when oiled or stained. I suggest testing the oil on piece of off cut sleeper first and see the kind of finish you get. If you are happy with the results, then you can commit the entire retaining wall.

I also recommend going to the Decking Oil and Stain Isle and have a look at the sample board finish. There you'll be able to see how the stains and oils look when cured.

If you have any other questions we can help with, please let us know.

Eric

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