Brick retaining wall

[LeoAU]

My second post.
I have a 11 m long by 0.5 m high retaining wall. True retaining, not decorative.

Have you used bricks or concrete blocks for a retaining wall? And then render it?
Couple of questions in regards to this.
Is this a more expensive option than sleepers?

1. Concrete foundation - 11m by 0.5m by 0.25m? Should I go any deeper? 300? 400mm? Is it enough - 500 mm wide? Even if it's 2m3 of concrete - it's around $350 here in <?xml:namespace prefix = st1 /><st1:City><ST1:pMelbourne</ST1:p</st1:City>.

2. Bricks - $300-350 or cheaper if bought on EBay. I'll need around 700 (double brick). Is it better to use concrete block - which are longer and higher, but more expensive?
Then mortar and render. Another $200?

[JDub]

scroll down the page about 10-15 posts ;)

There are some before and afters of mine and tcn's retaining walls.....

http://www.woodworkforums.ubeaut.com.au/showthread.php?t=34822

I considered using sleepers, then bessa blocks, ended up going with pre fab retaining wall system.....

Have also recently done a small TP wall as well for around the shed....

http://www.woodworkforums.ubeaut.com.au/showthread.php?t=34677&page=4

[LeoAU]

Yep, been to that forum. The foundation - how deep did you go? 2-300?
I am in Melbourne and the soil is not that hard, really sandy.

Price of blocks? Will it be much diff in here?

[laynlo]

I might be able to help answer some questions.
If its a "true" retaining wall consider using y12 bar set in the footing every 400mm for brick and blocks. If you decide to use block make sure you go for 190mm blocks. When you put the rods in the concrete work out where the wall will be starting and where the first hole of the block will be, and measure 400mm from that so then the rods will be in every second hole and dont need to be bent..... Another option with blocks is lay one coarse and the drill some holes and stick the rods in) core filling in a must do for retaining walls.

Since it is only 500mm high which will be 2 full coarses high and i would use a solid 90mm block laid on its flat for a capping and to get your 500mm height.

Most common problem with retaining walls is the footing is to small which can move in ways you dont want it to. stick with 350Wx400Dx11.5mL, depending on your ground. That is what id do for a class A ground.

Have seen sleepers bow and bend and look horrible.
Block calculation around 12.5/sqm 190mmx190mmx400mm
hope this helps

[LeoAU]

I might be able to help answer some questions.
If its a "true" retaining wall consider using y12 bar set in the footing every 400mm for brick and blocks. If you decide to use block make sure you go for 190mm blocks. When you put the rods in the concrete work out where the wall will be starting and where the first hole of the block will be, and measure 400mm from that so then the rods will be in every second hole and dont need to be bent..... Another option with blocks is lay one coarse and the drill some holes and stick the rods in) core filling in a must do for retaining walls.

Since it is only 500mm high which will be 2 full coarses high and i would use a solid 90mm block laid on its flat for a capping and to get your 500mm height.

Most common problem with retaining walls is the footing is to small which can move in ways you dont want it to. stick with 350Wx400Dx11.5mL, depending on your ground. That is what id do for a class A ground.

Have seen sleepers bow and bend and look horrible.
Block calculation around 12.5/sqm 190mmx190mmx400mm
hope this helps
The foundation - should it be one 11 m long concrete bed or should it be broken down into 2-3 part?
Blocks - should they be laid along or across,ie in a double brick pattern? If it's reinforced and filled, stretcher bond should do, right? You suggested 350W for the foundation, so it is stretcher, correct? :)

I am considering using sleepers wall vs blocks. Sleepers can look good, and as I see it less work plus less expensive exercise.

The blocks - how much and where I can get them in Melbourne? 11m x 2high = 55 blocks? So few?
Foundation - 1.5 m ~$350

Just trying to calculate what's cheaper - I still have to run it past my 'boss'. :D

[joe greiner]

On one of your posts in your previous thread, you mentioned proximity to a fence. Your excavation for retaining wall will likely undermine embedments of the fence posts. Depending on size of fence, posts may become wobbly; detrimental to fence and your wall. You may wish to reconsider stepped sleepers, but shorter horizontal step size; maybe even slight overlap.

I had a similar situation. Bought house a few years ago. Idjit contractor of 1976 had ground sloping down to house. Water in adjacent garage, as well as crawl space - NG for either. I used retaining wall, because I wanted maximum width for passage. Fence is quite high. I drove 4-foot-long steel channels each side of post embedment, and encased channels and post embedment in in-situ concrete lump for load transfer. Now facing all with split-face concrete blocks (no rendering), pipe drain, filter cloth, coarse rock backfill to avoid additional pressure from groundwater. (Blocks may have different name in Oz).

Joe

[laynlo]

The foundation - should it be one 11 m long concrete bed or should it be broken down into 2-3 part?
Blocks - should they be laid along or across,ie in a double brick pattern? If it's reinforced and filled, stretcher bond should do, right? You suggested 350W for the foundation, so it is stretcher, correct? :)

I am considering using sleepers wall vs blocks. Sleepers can look good, and as I see it less work plus less expensive exercise.

The blocks - how much and where I can get them in Melbourne? 11m x 2high = 55 blocks? So few?
Foundation - 1.5 m ~$350

Just trying to calculate what's cheaper - I still have to run it past my 'boss'. :D


A strip footing 11m long. Just make sure you have 3-11TM in there other wise pointless. Probably wouldnt hurt to have 3-11TM 100mm off the bottom on plastic stryups and put another in 100mm down from the top. (just tie it 100mm down from the top of your height pegs, that you laser along every 2-3m so a straight edge can reach them)...
Lay them strecher bond. Header bond would be to extreme and is not needed
55 full 190mm blocks + 28 solid 90mm blocks and that should do...
Dunno where to get them from in melb as im not from there. i think C+M is company around there that makes them (not 100% sure). I use a local made block down here and are 190mm $2.60each, 90mm solid $2each
so for $200+ materials isnt to bad especially if your skilled to lay them like us brickys;)

cheers

[LeoAU]

On one of your posts in your previous thread, you mentioned proximity to a fence. Your excavation for retaining wall will likely undermine embedments of the fence posts. Depending on size of fence, posts may become wobbly; detrimental to fence and your wall.

Joe

This is what I have, pelase don't get scared. :) Is this too close - appr. around 50cm from the fence line. SO, even closer to the posts. Should I move in by another half a meter?

[LeoAU]

Shold I wait for the new fence to be installed or build the new wall first?

[LeoAU]

55 full 190mm blocks + 28 solid 90mm blocks

cheers
full blocks I get it, what are the solids for?

[joe greiner]

Fence posts:

Hi, Leo. Your situation looks almost exactly like mine. Usually, 1V:2H is adequate for slope away from laterally loaded embedment, so 50cmV:1mH should work. But only needs to be in vicinity of posts, if you don't mind irregular plan. But, from later post, I surmise fence will be replaced. If so, you (or whoever replaces fence) can measure required embedment from the bottom of your wall. A little more digging, but gives you maximum flat space at bottom of wall.

Edit: If you do new fence concurrent with excavation for wall, no extra digging.

Joe

[myla]

hello,

do footing as deep as can possibly go, ie. 600 to 800mm

make sure you put drainage pipe behind wall and pipes thru wall

paint back of wall with bitumen paint and then line with corflute sealing joints with selant (good quality) and taped

core-filled besser or C+M concrete block is best,

if water gets in render will bubble out and weaken

thankyou
myla

[Doughboy]

Just a thought have you considered since you are replacing the fence why not put the retaining wall under the fence, if you can. that way you lose no extra ground. It also looks good and kills two birds with one stone.

Pete

[LeoAU]

Edit: If you do new fence concurrent with excavation for wall, no extra digging.

Joe
The fence is done by a contractor. Right after or just before the new wall goes in. Well, the weekend before or weekend after that is. What goes in first
that is the question.

[LeoAU]

Just a thought have you considered since you are replacing the fence why not put the retaining wall under the fence, if you can. that way you lose no extra ground. It also looks good and kills two birds with one stone.

Pete

Can this BE DONE?:confused: Flash with the fence you mean? Sound like a good idea, but what about all the drainage - where does the pipe go?
And when I start digging for the foundation which has to be like 500mm wide - I would have to go to (or rather under) my neigbours land?
This is sandy soil I have here - won't it all collapse? The fence and paving the guy next door has? :confused:

[joe greiner]

Please clarify neighbour's paving situation. Paver blocks or in situ?

Joe

[LeoAU]

The neighbour's got an area of appr 3-4 meters (against the fence) of paving bricks laid up to the fence. In about 50 cm the ground goes down, and that's where my retaining wall will be build.
I start digging, sand just streams down together with paving bricks... mess..
But I reckon when they start taking down the old fence, part of it will be destroyed any way...
Is there a chance the fence (new or old) may collapse when I dig to lay foundation? I'd have to poor concrete almost directly under the fence. :eek:

[joe greiner]

Technically, you should be able to combine the wall and fence constructions. Assuming your wall is engineered for full backfill, you can install vertical pipe sleeves (pvc best) for new fence posts in your wall. Helpful to embed about 1.5m rebar along top of wall. Drain pipe sleeves (weep hole in wall) to your new ground line. [After placing fence posts,] fill sleeves with clean sand and/or gravel. For construction, sand's angle of repose is about 1 vertical to 2 horizontal. So you need to excavate about 1m into neighbour's ground, after temporarily removing pavers. After placing drain pipe, work backfill up in layers: gravel, filter cloth, sand; gravel, filter cloth, sand; etc. Gravel zone should be about 10cm thick. Finally restore saved pavers.

Some unclear issues, though: Who owns the fence? Who is replacing the fence? Your contractor or your neighbour's contractor? If your contractor, is neighbour on board with this whole thing? Also need to consult contractor about logistics.

Your original plan would also require a horizontal clearance of about 1m for your foundation excavation, to reduce likelihood of undermining the neighbour's ground.

If all this has stirred the pot too much, I'd go back to my earlier suggestion of closely stepped sleepers, with completely separate construction of wall and fence.

Joe

[Doughboy]

I agree with Joe on this one and the neighbour should be liable for 50% of all the costs, if the niegbour is reluctant about moving pavers you should impree upon him/her that the pavers would need to be moved for the job to be done in a proper manner any way. The retaining wall sound like it will be to stop water from his side of the fence anyway so placing it under the fence would seem to be a better idea anyway. If the neighbour truely puts a fight up then offer to foot the cost of materials for the wall on your pat malone and he/she will only be paying for the actual fence itself. This way you still come out with a fence and wall. Good for both parties.

Pete

[LeoAU]

Thanks boys!

The neighbor is paying for half of the fence. The guy who builds the fence neither mine nor his - we found him in the paper.

Looking at complexity of combining wall and the fence, it'll have to be 2 separate structures.

What closely stepped sleepers ill achive vs just a sleepers wall half a meter from the fence? And how many steps would that be?
Do you mean 3 sleepers high (installing 2 sleepers) wall closer to the fence and then step back another half a meter and build 2 sleeper wall? :confused:

[joe greiner]

I'm not familiar with your sleepers. My murrican translation is RR ties about 6in x 8in (150mm x 200mm). Top one just at your side of the fence post. Top/(your side) corners on a line at 1vert to 2horiz, or maybe 1vert to 1horiz. Flatter slope more stable, but eventually bottom one is next to your house:D

Joe