I Beam Retaining wall

[oohsam]

Is the neigbours backyard ok...LOL Joke!
yeah I'll drain it somewhere. I read that its not good to connect it to your storm water as it could overfill and the water come back up the pipe...

So its ok to cover the coarse rock with backfill, or does the coarse rock need to go all the way up to the top of the wall for the width of the AG pipe?

[Gingermick]

Probably best if you get some geofabric to cover it.

[Tubby2]

I'm assuming this is the type of thing your talking about.
$37 per l/m seems a bit dear compared to a 100x100 post thats $15-$20 for 2400mm length.
I understand that there will be coach bolts to buy as well but still, does it really work out the same?

I need to do a retaining wall at the back of my place, about 35 l/m

[oohsam]

Yes tubby thats the stuff.
The cost is roughly the same, which is about $200 difference in total. Thats hardly much (To me) when I look at the amount im spending on my garden/deck etc to make this sort of descion.

Im still unsure which way I am going to go...

[Planned LScape]

If employing a contractor to do the job, I/H beam would be quicker and have less labour costs associated with it, as the sleepers just slot in after the posts have been set, but as you're doing it yourself it would pay to tally up materials and see what would be cheaper. But, depends on what will be easier on you to, and what will be quicker and if you're prepared to work on it longer for a particular design style.

[fenderbelly]

you could try steel salvage yards for your I beams.

[Terrian]

bahahahah sorry bout that. I meant 1.1meters or 1100mm.

Thanks for the replys guys.
$33 a meter is so damn expensive...Would be cheaper to build it from just sleepers.

2.1x75 pine sleeper, less than $20 each, you want lengths of about 1.7,

$33 x 1.7 = $56,

I am having trouble seeing how steel is going to be about the same price as treated pine

[namtrak]

I am having trouble seeing how steel is going to be about the same price as treated pine

Okay this has been bugging me for a few weeks now, so I thought I would take the ten minutes it takes to figure it out.

For this example, I am building a hypothetical 10m long fence, which is 800mm high. Now, given that we are using the same 100 by 75mm treated pine sleepers as the rails, and we need the same amount of concrete, aggregate for drainage and ag pipe etc. The only point of difference price wise are the actual posts.

Assuming that we use the standard 2.4 lengths of rails we need 5 posts set at 600mm deep.

For the steel that would be 5 steel posts at 1.4m long at $30.27 per metre for a sub-total of $212 add another $25 for the cost of the 5 cuts and the total is $237

For the treated pine posts it would be 5 treated pine posts at 2.4m long at
$26.40 each (I have assumed the retaining wall is built for longevity using the standard 100 by 200 sleepers) for a sub-total of $132. Then we need to add the cost of the galvanised coach bolts. Once again doing it properly there are 4 per rail times 16 rails at $1.60 each for a sub-total of $102.40. Which gives a total cost of $234.40.

Now, I'm not yet finished. There is an unfactored time cost for drilling, and bolting up the 64 separate holes, the wastage of about 5m of treated pine, and the durability of the steel over the treated pine.

Make sense?

[Pulse]

Saw those posts advertised in metalcorp brochure today, if I still had it I'd tell you the price! It was sold as a retaining wall sleeper post/

Cheers
Pulse

[Terrian]

Okay this has been bugging me for a few weeks now, so I thought I would take the ten minutes it takes to figure it out.

For this example, I am building a hypothetical 10m long fence, which is 800mm high. Now, given that we are using the same 100 by 75mm treated pine sleepers as the rails, and we need the same amount of concrete, aggregate for drainage and ag pipe etc. The only point of difference price wise are the actual posts.

Assuming that we use the standard 2.4 lengths of rails we need 5 posts set at 600mm deep.

For the steel that would be 5 steel posts at 1.4m long at $30.27 per metre for a sub-total of $212 add another $25 for the cost of the 5 cuts and the total is $237

For the treated pine posts it would be 5 treated pine posts at 2.4m long at
$26.40 each (I have assumed the retaining wall is built for longevity using the standard 100 by 200 sleepers) for a sub-total of $132. Then we need to add the cost of the galvanised coach bolts. Once again doing it properly there are 4 per rail times 16 rails at $1.60 each for a sub-total of $102.40. Which gives a total cost of $234.40.

Now, I'm not yet finished. There is an unfactored time cost for drilling, and bolting up the 64 separate holes, the wastage of about 5m of treated pine, and the durability of the steel over the treated pine.

Make sense?

I see your figures, and wonder why you would buy 2.4m x 100mm sleepers when you want 1.4m for the posts, buying 2 3.0 x 75 and 1 1.8 x 75 would be a cheaper option,

Working from memory (about 2 years since I was last selling garden supplies), about $30 each for the 3m sleepers & $14 for the 1.8 sleeper, about $74, add your 102.40 for gal bolts, gives $176.40, quite a lots less than $237, but, thats just my take on it (says he who has just used 3.0m bridge timbers and about 2.4m 'b' grades, expensive way to build a wall) (oh yeah, no bolts

75mm will last just as long as 100mm for the posts (about 20 years if I recall) and a heck of a lot less wastage.
As for the time factor for drilling holes, really it is a non issue for the person building the wall themselves.

If you really want the wall to last longer than a lifetime you would use steel posts & concrete panels (thats the next wall I build!)

[Planned LScape]

Depending on wall height however the 2.4m 75 or 100mm sleepers are the stronger option. Anything over 2 sleepers high I go 2.4 lengths.

[Tubby2]

Saw those posts advertised in metalcorp brochure today, if I still had it I'd tell you the price! It was sold as a retaining wall sleeper post/

Cheers
Pulse

I gave them a quick call and the price was $45 l/m. They come in pre cut lengths starting at 900mm and increasing in 300mm increments. These a Galvanised and 5mm thick