# Forum Home Renovation Retaining Walls  cladding pine sleeper retaining wall in merbau

## rog1009

Hi, long time reader first time poster 
I would really like your thoughts/opinions/advice on my retaining wall project: 
So far I have constructed a 0.4m high by 16m long retaining wall about 2.5m from the fence on the north side of our block. The retaining wall was made by cementing steel C and I beams about 2400mm apart and slotting 2 H4 pine sleepers (2400 x 20 x 75) into the gaps. I have placed an agi pipe along the rear of the wall surrounded by aggregate and wrapped in geo fabric. The agi taps into the storm water. I have backfilled the area with soil and am in the process of laying pebbles on the top. 
I plan to clad the front of the retaining wall in merbau decking (laid horizontally) and I just want to check that my thought process is correct. 
After reading some advice on this forum I have packed the gaps between the sleeper and the I beam with builders wedges to prevent twisting and inserted 250mm x 9mm deck spikes into the tops of each sleeper to prevent bowing (4 to a sleeper). I also plan to screw a 3mm x 20mm steel bracket over the top and bottom sleepers with coach screws to further prevent bowing. I hope this will be enough?? 
After that I plan to cut some treated pine spacers (not sure of the correct word) and attach to the face of the retaining wall every 900mm or so. The merbau will then be screwed (stainless steel countersunk screws) to the spacers to hopefully prevent the merbau sagging. 
The reason I need the spacers and cant attach the merbau directly to the face of the sleepers is because the I beams jut out about 10  15mm from the sleepers. 
Ill then cap the wall with merbau. 
Does this sound OK? Im paranoid that the pine sleepers will warp and bow and in the process push the merbau out of line? 
Any advice would be much appreciated. 
Cheers.

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## DEMAK Timber

Sounds Great, would love to see photos of the finished product. 
Just a thought regarding movement in the sleepers, (they will move slightly regardless of what measures you take) could you run a steel bracket just off the face of the sleepers then screw your Merbau straight to that..? 
Just trying to think outside of the box, feel free to ignore...  :Sneaktongue:

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## rog1009

Hi Demak, thanks for the advice  great idea as I guess it means I wont have to attach anything to the sleepers but instead run a bracket from steel post to steel post and attach the merbau to the bracket. 
I imagine I would need to secure 3 or 4 brackets horizontally from post to post and attach the decking to each bracket at about 900mm intervals. Depending on the width of the decking used I would need 3 or 4 horizontal rows of merbau for a 400mm high wall, hence 3 or 4 brackets? 
What would you suggest I use as a bracket to hold the weight of the merbau without sagging? 
Would steel tubing (say, 20 x 20 x 1.6mm) do? Or would steel ceiling battens suffice instead? Do you think a ceiling batten at about 0.5mm thickness would be strong enough to support the weight of the decking? 
Thanks again for your help.

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## DEMAK Timber

Are you cladding horizontally or vertically? Sorry, I'm a bit confused. I was assuming horizontally so the brackets would need to go vertically down the face of the wall...?
Are you going to clad over the top as well? 20x20 would be ok but I would probably go 25x25 as it gives a bit more room for screws. (a 40mm screw will not touch the other side of the RHS wall when fixing a 19mm board to it..)
If you need the brackets welded up let me know, I could make them today and courier them out to you. 
Cheers,
Daniel
03 9756 0444 sales@demak.com.au

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