Browse Forums Landscape & Garden Design 1 Mar 31, 2011 5:58 pm Hi, just hoping someone can help me with whether it's OK to use batten screws to attach the horizontal timber sleepers to the upright posts in a retaining wall? I figure the uprights will be taking all the load anyway, so is there any use for bolting all the rows on, or is it more a cosmetic thing? I understand the bottom row should be bolted anyway, but have read in a few places online that screws or nails are sufficient for the other sleepers. Can anybody shed any light on this? Thanks for the help Re: Timber retaining wall - how to attach sleepers to posts? 2Mar 31, 2011 7:57 pm I assume you mean when using timber posts too? Coach bolts through each sleeper should be used in my opinion. Its about $1 per bolt and will make it much stronger. Re: Timber retaining wall - how to attach sleepers to posts? 3Mar 31, 2011 8:39 pm If they are treated pine the main reason for the strength is for when the pine dries out and starts to warp - which it will. You need some heavy duty bolts to hold them flat against the posts and even then they can twist dramatically. I've used M12x100 coach bolts with a hex head which is recessed into a 28mm counterbored hole in the face of the post. A clearance hole of 12.5mm is used in the post and a 10mm hole is used in the sleeper which the bolt thread will tap into. You'll need an 18mm socket to tighten them as the hole is recessed but they look better this way. Some people use a washer under the bolt head to stop the bolt from biting into the pine but you don't want to do them up too tight anyway as it may strtip the hole. Another option is to use a domed head coach bolt with a nut on the other side of the sleeper - less labor but more expensive. I'd think about two bolts per post for 200x75 which will prevent the sleeper from trying to pivot against the post and pull on the bolt or cuping around the bolt location - a bolt near the top and bottom of the sleeper stops this happening. Sounds over the top but treated pine is a rubbish material if you need a wall to stay straight and look good. Another option is use red wood which I'm led to believe does not warp as badly. Re: Timber retaining wall - how to attach sleepers to posts? 4Mar 31, 2011 10:14 pm 1) I would never have timber of any sort in contact with soil 2) the only steel I would ever use in the ground would be 316 stainless think about the permenancy of your solution. Re: Timber retaining wall - how to attach sleepers to posts? 5Apr 01, 2011 9:42 am keen 1) I would never have timber of any sort in contact with soil 2) the only steel I would ever use in the ground would be 316 stainless think about the permanency of your solution. H6 treated pine is designed for sub ground level use. If you are really concerned plastic sheeting can be used for extra protection. As for stainless, if you wanted to spend that sort of money thats up to you. I would imagine that 316 stainless 100 section I beams would be somewhere between $200-500 per meter Galvanized steel will outlive my children's children( daughter is 18 months old, so it'll be a while) if you are really worried, paint it with bituminous paint before setting in concrete, same for the treated pine in contact with the soil. But the best thing about the gal upright design is you can get a circular saw and cut the bottom sleeper in half, pull it out slide the other down and drop another in the top. Rinse & repeat. I'm a big fan of stainless over mild steel for lots of things but I think this is way over the top. Re: Timber retaining wall - how to attach sleepers to posts? 6Apr 01, 2011 10:39 am Thanks everyone for the helpful replies. Yes, the uprights will be pine sleepers also. Steel would be great but stretches the budget too far. I can see the sense in going with bolts now, and 2 on each end too. 180 bolts coming up Re: Timber retaining wall - how to attach sleepers to posts? 7Apr 01, 2011 4:26 pm Sorry, just one more question and I figured I shouldn't make another new thread. Anybody know how many pine sleepers (2.4m x 200mm x 50mm) a standard 7x4 trailer could take in one go? I'm guessing weight would be the factor more so than volume. I just found out that the supplier won't deliver on the weekend (oops), so am faced with ferrying 57 of them to our house in the trailer. Re: Timber retaining wall - how to attach sleepers to posts? 9Apr 02, 2011 8:46 am Quote: would imagine that 316 stainless 100 section I beams would be somewhere between $200-500 per meter Galvanized steel will outlive my children's children( daughter is 18 months old, so it'll be a while) if you are really worried, paint it with bituminous paint before setting in concrete, same for the treated pine in contact with the soil. But the best thing about the gal upright design is you can get a circular saw and cut the bottom sleeper in half, pull it out slide the other down and drop another in the top. I was not implying stainless 100 section I beams as I would not have a sleeper wall in the first place. If you are committed to a timber wall then I would definately use stainless fixings. Stainless Steel Store (internet) have some reasonable prices. Not 100% on this but I thought it was best not to coat galvanised steel with anything (bitumous paint included) as it can effect the galvanic action of the coating. (?) Re: Timber retaining wall - how to attach sleepers to posts? 10Apr 04, 2011 9:51 am My mistake. Agree with stainless fittings/bolts. You may be right about the bitumen vs gal. Re: Timber retaining wall - how to attach sleepers to posts? 12Apr 04, 2011 2:50 pm nemisis Why do people use timber for retainer walls? Insane! It will be pushed over in a few years. The number 1 reason is cost compared to other materials Re: Timber retaining wall - how to attach sleepers to posts? 15Apr 04, 2011 8:56 pm nemisis KnockItDown The number 1 reason is cost compared to other materials and when you need to replace it from warping/white ants/break down??? If it's done right warping won't be an issue. Granted, breakdown is faster with timber than say a masonry product but for those on a budget, the price, and the ease of DIY to also keep costs down will win out most of the time. The immediate cost of materials and labour are the first things that most ppl take into consideration. Lifespan runs 2nd in most cases but in saying that, using timber such as treated pine in certain circumstances and making sure the drainage is done correctly (the reason most walls fail is poor drainage) will ensure the wall has a long working life. 4 9062 Old Home Restoration / Renovation Cheers mate! This is exactly what I was thinking but wasn't sure if it was something I'd find on the shelf. I agree with you, fixing the brackets to the board will look… 2 3276 looks ok to me, round logs retaining walls are better than sleeper walls, more even preservative treatment and stronger since they include the whole tree and not just part… 1 2602 |