attaching galvanized posts to concrete wall

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I need some advice (not sure whether welding or other solution is better)In the backyard I have a concrete wall approx 1m high and I want to attach galvanizedpipes/posts 33.9mm O.D / 3mm wall thickness  (for a fence trellis for kiwis) to the wall.I was thinking of having the pipes 0.5m in the ground (add some rock/gravel in thehole) and 2m above ground fixed (bolted or other means of attachment) at two heights on the wall.Now, the wall is as old as the hills and I've had considerable problems before tryingto attach eg a clothes line/post to it using brackets and bolts - the concrete is not very homogenous with spots having a large percentage of sand / bolts don't hold very well.A friend suggested drilling holes at 45 degrees on each side of the post andhammering in 10mm/12mm rebar into the holes and welding it to the galvanized postsat two heights and spraying the rebar and weld area on post with zinc paint in a spray can.Any better idea ? If not, should I flap sand the post - my friend suggested justusing 6013 electrodes and welding directly without sanding.
Reply:There's a lot of options for attaching things to concrete.There's the usual lead shields and lag screw, expansion anchors, and tapcons. Since you say you've had issues in the past I'll skip most of these, though they would be my 1st choice usually. There's also the old drill a hole and drive in a wooden dowel and then run screws/ lags into that as well. All these are friction fits.Next option I would go with would be epoxy. You drill out a hole and clean it out well. Usually than means blowing it out with an air compressor followed by a bottle brush to loosen any remaining dust and blow it out again. They sell epoxy in caulk like tubes that can be used in standard caulk guns or they sell special guns used to dispense epoxy. For a one time job I'd use the caulk type tubes. Have everything preped and do all the bolts at once because as soon as you use the tube the mixed 2 part material in the caulk tube will start to set. The specialized guns usually have removable dispenser tubes and you can just replace the tube if you don't use it all at once. You squirt the epoxy in the hole and then push in your threaded rod and leave it for roughly 30 minutes. After that you can tighten the nuts. We use epoxy to set rebar in walls as well as bolts. We usually use HILTI epoxy in the specialized dispenser ourselves. Pull out on the epoxy is based on the base material strength and is about as strong as you can possibly get if done right. If you need more strength, use larger fasteners, deeper holes or more fasteners, to lessen the load on each individual one. The idea is to have more surface contact with the base material.You can also use anchoring cement, but that's usually a PITA on a vertical surface. That would be my 2nd choice however over epoxy on a flat surface. You use it just about the same as far as prep is concerned..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Why not dig a hole 2/3M, set the pipe close to the wall and backfill with wet concrete? Does it actually HAVE to be attached to the wall or will close be good enough? It sounds like you are wanting the wall to provide some of the support for the pipe. Concreting it into the ground works well as long as the hole is deep enough(2/3-1m should suffice in this instance) As old as you say the wall is, this may be a better solution, especially since you mention how porous the material is. Just let the concrete harden for a day or two before mounting the trellis. If the wall falls over in the future the trellis will stil be standing, unless the wall falls the other way. In which case the trellis pipe may keep it propped up.
Reply:thanks for all the info ! Bistineau- Yes I'd prefer to have the posts againstthe wall and use the wall as support as I don't have much spacefor plants etc.. and would otherwise need to make quite a few holesand quite a bit of concrete (got a few of these posts to put inalso in another area).DSW - when using screws - would you use a bracket either one of thosethat wraps around the pipe and lies flat on each side of the pipe for the screwsor the type which is screwed into the wall behind the pipe and it clamps all theway around the pipe (have tried something similar for a satellite dish but see thatthe bolts and bracket are rusting AND the bracket is quite expensive to buyespecially since I need quite a few of them)- for the rebar you mention - this is similar to what my friend mentioned (weldingthe rebar to the pipe) but I'm not sure how durable the zinc spray paint would be but it may be the cheapest solution (few pieces of rebar vs at least 4 bolts + anchors + brackets)Another thought - does it make sense to drive rebar ainto the wall at an angle on each side of the pipeand then take some bent steel put it around the pipe to meet the two pieces of rebarand weld that (instead of welding directly to the pipe) and spray zinc over this ?Last edited by vjeko; 12-14-2011 at 04:02 PM.
Reply:There's an endless array of hangers you could probably build or use to do this. Kind of tough to tell what would work best without seeing the job. I've used many brackets similar to these I pulled picts of. All depends on the job and what was needed and how I needed to mount them. The single hole strap and the double hole strap ( single rather than the double I found a pict of) are what I use most times if I have to mount pipe to a wall. The wrap around with the single post I usually use for pipe running along a ceiling rather than vertical, but I've done it that way too a few times.Rust is usually due to using fasteners not designed for exterior use. Use galvanized hardware or paint to limit rust.Rebar would not be my choice at all. All the bar we epoxied was for tying steel to existing concrete, either walls or footings and the bar was buried in the pour and generally not exposed. I can think of a lot better materials to use honestly than rebar, especially if you are trying to avoid rust. Attached ImagesLast edited by DSW; 12-14-2011 at 04:40 PM..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Drill a hole through the Galvy Pipe and then run all thread or a Long carriage Bolt through the Hole in to the Concrete wall, securing  with the Epoxy DSW mentioned.Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:hi, if you want to avoid welding you can drill wall and use a female threaded concrete wedge type anchor there .Use all thread rod like stated above with holes in pipe. You can use acorn cap nuts or cut rod short and weld.
Reply:I would also recommend epoxy. It's the best way to anchor anything to concrete, the only down side is that it's slow. Acrylic epoxy is much faster, it gets hard in under an hour, but it's a little more expensive. Acrylic can be a hassle sometimes because it tends to get hard in the tube if you don't go fast enough.I would drill holes through the pipes to bolt them to the wall. Because you are so close to the sea you should coat the inside of the holes with cold galvanizing paint. I'd use all thread, nuts and bolts of stainless steel or hot dipped galvanized.Last edited by fortyonethirty; 12-14-2011 at 08:12 PM.Ian TannerKawasaki KX450 and many other fine tools
Reply:OK, thanks for all the input ! - will now consider all the ideas - think the bolt/anchorthrough the pipe may be the simplest solution.Before proceeding I'd still really like to know your reason(and my friend is curious)whythe idea my friend is proposing is not a good one(on either side of pipe, drill holes at an angle away from pipe and hammerin rebar 10mm - 12mm thick , weld rebar to pipe and paint with galvanized paint - do this at two height levels for strength). I just popped over to my friends place where he showed me a painted black square profile pipe which has been attached to a garden wall in this way - it holds an old boiler of 80l (so we're looking at some 100kg of weight at the top of a 2m pipe) for "solar heated" water/shower during the summer and it's therefor over a decade.  If I see the solution with bolts/anchor is giving me a headache due to  quality of the wall/sand pockets, and I try the above idea,should I sand the galvanized pipe before welding / is 6013 rod OK + galvanizedpaint on top ?
Reply:If the wall won't hold an anchor but is fairly sturdy, Just drill all the way through the wall and use long bolts or all thread rod and bolt through the post to the wall. Use a big washer or plate on the otherside and nothing short of breaking the wall will move the pipe.
Reply:Originally Posted by vjekoBefore proceeding I'd still really like to know your reason(and my friend is curious)whythe idea my friend is proposing is not a good one(on either side of pipe, drill holes at an angle away from pipe and hammerin rebar 10mm - 12mm thick , weld rebar to pipe and paint with galvanized paint - do this at two height levels for strength).