How to attach Ekodeck onto concrete sleeper retaining wall?

[DIYHome]

Hi community,

Would need some advice on covering our concrete sleeper retaining wall at the front of the house please

We have already purchased ecodeck decking boards to cover them but need to know we are doing the right thing before we start.

I understand that we need to fix timber onto the steel post and then affix the ecodeck as you would normally do and same as the capping. Below are my questions pls

1) What type of screws should I use to fix timber onto steel post ? Do I also need to glue the timber as well ?

2) Sleepers are 2m wide and the wall is 600mm height , so we are thinking of 2 treated pine timber one on the top and one somewhere in the middle https://www.bunnings.com.au/70-x-35mm-outdoor-framing-h3-treated-pine-2-4m_p8032103

3) How to fix the capping ? Steel post is 100mm wide and sleeper thickness is 80mm if that helps 

Appreciate your help

Thanks !

[Dave-1]

Good afternoon @DIYHome 

Having a think about what you want to do I would actually be tempted to not fasten to the steal posts of the concrete sleeps. mainly because you cant get a bolt through them and I dont know if the sleeper would stand up to be drilled so close to the end of it.

If you put in three posts that butt up against your 2m concrete sleepers then you will be able to attach your composite decking to them. For the capping id actally go a little wide so the look of your post would be straight up, over and then down a little. Like a large square hook. The hook over the top will hold the post in place at the top, the capping and inside skirt will give it ridgility. 

This way you ar not changing the way the concrete sleeps are supported, you are just dressing around them.

Dave

[EricL]

Hello @DIYHome 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about attaching Ekodeck to your retaining wall.

It's great that you've received excellent advice from @Dave-1. I was thinking about Dave-1's explanation of creating a large hook that would go over the sleeper. It can be done with the 70x35, and I propose using Selleys 350g Liquid Nails Heavy Duty to glue the frame to the concrete sleepers. I've drawn a sample image below to give you an idea of what Dave-1 I believe is proposing. 

Please have a good look and let us know if it this design is acceptable to you.

If you wish to modify the setup, please let us know.

Eric

[Dave-1]

 @DIYHome and @EricL 

Yep, got it in one! Nice work

Dave

[DIYHome]

Hi @Dave-1 & @EricL 

Thank you so much for you time and the detailed explanation.

Apologies for not being clear with my question, we want the 70*35 timber to go horizontally and the final look of the ecodeck boards to be vertical.

So we will not be able to glue the timber to the concrete sleeper as it is not flushed with the steel post.

So we need to somehow screw the timber battens on to steel post horizontally and then fix the ecodeck

Hope there is a solution to this ?

Thankyou

[Noyade]

Afternoon @DIYHome 

Any chance of some close-up photos, looking down on the retaining posts - just to see what gaps there are and what dimensions are available?

I was thinking along the line of drilling - then tapping threads for bolts...

You wouldn't need much.

Cheers.

[Dave-1]

Afternoon @DIYHome 

Mmmmm First up I hesitate drilling into the gal posts, there is no room to screw bolt anything between the steel and the concrete and I dont trust the sleeper to not fracture as you try and drill through it. They look like a very tight fit.

I would still go for the "Hook" option over the concrete and then have your 35*70mm timbers laid horizontal between the hooks, i would still suggest 3 hooks over the 2m. You could then attach your eco deck in vertical pieces. I dont think gluing would work to well.

To save width you could make a "Hook" with a piece of say 3mm flat bar and bend it, tho that would be difficult to keep all the hooks the same.

Dave

[EricL]

Hi @DIYHome 

It appears that @Dave-1 has gotten ahead of me this time. I was going to suggest adding rails to the timber hook technique which would allow you to install the panels vertically. I've placed a sample image below to give you an idea of how it can be done. The timber hook technically can be placed right next to the steel post with additional small rails that will allow you to place the horizontal panels over the steel post in order to hide it. 

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

Eric

[DIYHome]

Hi @Noyade more pics attached as requested and thank you for the reply

[DIYHome]

Thank you @EricL and @Dave-1 

So should I use liquid nails in order to attached the timber framing to the concrete sleeper ?

Apologies for too many questions completely a newbie trying to pretty up the retaining wall