Building Small retainer wall

Discussion in 'Landscaping and Outdoors' started by michaels2411, Jan 3, 2017.

  1. michaels2411

    michaels2411 New Member

    Hi there,
    Just double checking a few things if I may. I'm looking at building a small 30-40cm wall made of two course staggered sleepers. There is no slope, just a few small trees/soil which the mini wall is to retain.

    Thinking the steps required are:
    1) Dig trench, Sleeper width wide, 50mm of sub-base or gravel (does it matter)?
    2) Pilot bottom row of sleepers and Rebar into ground.
    3) Screw second (top) layer into the bottom layer of sleepers.

    Anyone see issues with this approach, is the course below the sleepers required for such a small wall and if so whats the best material for this layer?

    Thanks for looking.
     
  2. sospan

    sospan Screwfix Select

    Much easier to dig a little out and put the gravel down to level it out.

    rather than screw top layer down you could use an auger bit to drill a pilot hole from the top sleeper through the bottom one and then hammer rebar in from the top into the ground. Should hold everything true and solid.
     
    Joe95, wiggy and michaels2411 like this.
  3. michaels2411

    michaels2411 New Member

    Many thanks Sospan, was thinking an auger through them both, guess that way I also have less chance of sheering a screw from top row into bottom row.
     
  4. fostyrob

    fostyrob Screwfix Select

    Have done a similar project recently.

    Is it a straight wall or will you be having any corners etc.?

    What type of sleepers are you planning on using? With the really heavy sleepers (reclaimed hardwood) I suspect you will need little in the way of physically securing to the ground as the weight will take care of that. Also if you have any corners etc it is unlikely to tip over.

    I dug a trench and filled with hardcore compacting to about 50mm. Levelled and popped the bottom sleeper in so it was just proud of the original ground. Just to be secure I as Sospan says augered 3 holes per sleeper (260cm long) through which I hammered 50cm long M22 threaded rod. Afterwhich I secured each sleeper layer with timberlok screws. I used 6mm diameter screws that extended 5cm+ into the sleeper below (30cm long). Probably overkill but it is not going anywhere in a hurry.

    Remember to install some sort of drainage at the back. Given as you describe a relatively small wall I would just tip some pea gravel or equivalent at the back. The sleepers are not going to form a water tight seal so I wouldn't think hydrostatic pressure would be a major issue.
     
    michaels2411 likes this.
  5. Joe95

    Joe95 Screwfix Select

    I would drill a 25mm using an auger bit and hammer home a large oak dowel. Not sure what the proper name is?
    Don't like the look of large metal fixings in the middle of a nice light coloured sleeper.
     
    michaels2411 likes this.
  6. fostyrob

    fostyrob Screwfix Select

    I would just put the metal fixing through the bottom one or two depending on how many tiers. Top one just fixed with countersunk timberloks then covered in a small dab woodfiller from the produced dust.
     
  7. michaels2411

    michaels2411 New Member

    Thanks all - great input and different views. The wall will only be 2 layers high. I'm using modern 100x200x2400 sleepers, so fairly light compared to reclaimed ones. It will span about 12m long but its straight so should be fairly easy in truth. Trench down with hardcore/sub-base. Then pea gravel soil side for drainage. Auger through first layer of sleeper, rebar in to the ground. Then timberlock the second into the first layer of sleeper. Wood fill over the screws and hopefully job done.
     
  8. mr_e

    mr_e New Member

    Hi all I’m about to start a similar project and interested in how easy it is to hammer rebar or steel pins down through the compacted MOT sub base? Am I going to end up with a broken hammer and lots of bent pins/rebar? Also I’m assuming plastic pins (much cheaper for my project) are a no-go?!
     

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