My Covid Project - Rebuild Retaining Wall and Fence

[hcoles]

I need my head examined.
My retaining wall and fence has been leaning recently 20 or so years after I put it in.
I made some install mistakes 20 years ago and I'm paying the price now.

I started removing the fence and wall to see how easy or hard it would be. It's not easy but the ground is still damp so the digging is not bad.

Behind the wall is a French Drain pipe and another pipe that carries the neighbors roof water to the street. There are other pipes I'm running into that the neighbor installed for irrigation. At the bottom and behind the wall (around the French Drain pipe) I put in drain rock and fabric, I'm removing the drain rock trying to keep it clean to reuse.

I "invented" a method to pull out the old posts. See pictures. First I use a floor jack and then a farm jack.

I have a number of questions or plans you can comment on:

1 - I'm planning to go with 6"x6" PT posts compared to the 4"x4" originals. How deep would you make the holes? The wall is about 2.5-3foot high.
2 - Should I reuse the retaining wall PT 2"x12" boards - they look pretty good no rot. I suspect the chemicals are mostly gone. Reusing is probably not wise, might cost $600 or so to replace.
3 - I'll pour the concrete much higher and slope it away from the posts to keep them dry and out of the dirt.
4 - I'm looking at using PostProtector sleeves - anyone use these?

Thanks for any constructive input.

[flatbutt]

Originally Posted by hcoles

1 - I'm planning to go with 6"x6" PT posts compared to the 4"x4" originals. How deep would you make the holes? The wall is about 2.5-3foot high.
2 - Should I reuse the retaining wall PT 2"x12" boards - they look pretty good no rot. I suspect the chemicals are mostly gone. Reusing is probably not wise, might cost $600 or so to replace.
3 - I'll pour the concrete much higher and slope it away from the posts to keep them dry and out of the dirt.
4 - I'm looking at using PostProtector sleeves - anyone use these?

1 An 8 foot post would get sunk about 3 feet if you plan on using the entire length of the post. If the wall is only 3 feet high why not just stack 8 x 8 inch PT ties?

2 Using boards to build a wall is not the way I'd go YMMV but in any case I would not re-use them.
3 OK if you decide to go with posts

4 I've never used them.

Have you considered using Lok blocks for the wall?

[billybek]

Different conditions but I just finished a covid fence project last weekend.
It was the last stretch of fence that I hadn't replaced over a twenty year period and it was about ready to fall over. Posts were cedar and rotten and of the 5 I only was able to get one out in its entirety.
I went with the new brown pressure treated on this one as the green p/t is no longer available or not easily available here. The end cut treatment on these says no ground contact. Ok...

I went with 10 foot 6x6 posts and they are in 4 feet. Dug the holes a bit deeper than required and dropped the posts in and tamped the bottom with the weight of the post. Threw a bit of crush gravel to get under the post for drainage and then mix one bag of post haste concrete in the wheelbarrow and place it at the bottom of the post. After it sets I fill the post hole gradually with 20mm crushed gravel and tamp it in as you fill.

I am not a fan of filling the post hole with cement. It keeps the post wet, not allowing moisture to easily migrate away from the post. The post will eventually shrink and leave the fit loose.

Will post a photo of the end result. It will be the last fence that I ever build on this property.

There are some guys around here using some sort of foam that fills the post hole. Not sure what that is all about.

[billybek]

Not a good neighbor fence even though i have great neighbors.

I would not reuse any of the old material.

[dad911]

The strength in a retaining wall, and what keeps it from blowing out, is tying it back into the dirt being retained. 20 years ago we built a timber wall, 16' high in places, that was basically 'boxes' filled with stone and dirt. Only the face was solid. still standing. Like this:

For a paver type wall-stone more than a few feet high, mfg typically specs a geogrid :



In any event, you want to tie it into the bank.

[RWebb]

build forms and pump in concrete

also... you cheated and took the easy way out by using an automotive jack to pull that concrete up

if you really needed your head examined, you'd have swung a sledge at it until something split in half

[hcoles]

Originally Posted by dad911

The strength in a retaining wall, and what keeps it from blowing out, is tying it back into the dirt being retained. 20 years ago we built a timber wall, 16' high in places, that was basically 'boxes' filled with stone and dirt. Only the face was solid. still standing. Like this:

For a paver type wall-stone more than a few feet high, mfg typically specs a geogrid :



In any event, you want to tie it into the bank.

Yes, if I had a reasonable chance to get access and take the bank away I would install tie backs or deadmen or concrete "L" as should be done. Considering my neighbor doesn't want a bigger part of his yard tore up, I'll try to do the best I can and build something to last 30 years - then I'm out anyway.

[look 171]

Unless it has to be wood and you like that look, why not concrete or the blocks Dad911 mentioned?

[hcoles]

Originally Posted by billybek

Not a good neighbor fence even though i have great neighbors.

I would not reuse any of the old material.

Yes, I'm now leaning toward not using the old wall boards. I am thinking of using the old pickets.

That's a nice looking fence. It looks like "good neighbor" to me.
Is that because the pickets don't overlap? The current (old) fence had overlapping pickets. Not sure how I will do this again, I don't really like the way I did it before.

Any diagram(s) of the typical assembly for the fence part?

[hcoles]

Originally Posted by look 171

Unless it has to be wood and you like that look, why not concrete or the blocks Dad911 mentioned?

I don't think I have the room for concrete blocks what the proper geo fabric to tie things back. The wall would be about 3-4 feet high, I don't trust that I can build a block wall that high and do it properly.
A proper concrete wall has an "L" shape with the bottom pointing in and probably in about 3 or more feet. This would mean I need to go in about 4' feet and a bit more. This would mean really digging into the neighbors yard.

[look 171]

Its a considered a garden wall if its under 3". No permit needed here in LA and I know we have a pretty tough building code, PITA actually. I have seen walls without the fancy "L" shape hold up for years. Taken out enough of them.
this will hold up for years if you don't have mountains of dirt to hold up on the other side. Make sure you have weep holes or good drainage. I can't see the rest of the place to help with much.

[look 171]

Forgot, the footing may need to be 10-12" thick. Plenty. It will last until your grand kids college grad. and then some.

[hcoles]

Originally Posted by look 171

Forgot, the footing may need to be 10-12" thick. Plenty. It will last until your grand kids college grad. and then some.

Thanks for the drawing. Yes, I think in our City/County if the wall is under 3' then there are few if any requirements. I do need to put a fence on top of the wall.
Getting the grand kids in/out of college is the goal. I won't be doing much digging at that point.

[vash]

I have software at work that I can run some numbers for you. But seeing that well behaved Soil stand up unsupported will give any engineer The warm and fuzzies.

In general, down and dirty. If you went 1/3 in the air and 2/3 underground the numbers work. So sink the post 6 feet down. The state of CA has 6x6 post stuck in the ground everywhere. They last a long time. Our metal beam guard rails utilize that beam.

Make sure you backfill up against the wall with gravel to get full bearing and allow drainage. You could do a small French drain back there.


I pulled post foundations the exact same way. A two ton jack with that lever is pretty impressive.

[hcoles]

I was planning to backfill with drain rock and filter fabric with a french drain pipe at the bottom.

I'm now looking at steel galvanized pipe (2.5-3.0" dia.) instead of 4x6 or 6x6 wood PT posts.

[look 171]

Originally Posted by hcoles

I was planning to backfill with drain rock and filter fabric with a french drain pipe at the bottom.

I'm now looking at steel galvanized pipe (2.5-3.0" dia.) instead of 4x6 or 6x6 wood PT posts.

You talking chink link fence pole? I wouldn't do it, it isn't strong enough,IMO. How much of that soil are you holding up. Can't see it from the pic. Its not a mountain back there? Its just pretty much flat that go back some?

[hcoles]

Originally Posted by look 171

You talking chink link fence pole? I wouldn't do it, it isn't strong enough,IMO. How much of that soil are you holding up. Can't see it from the pic. Its not a mountain back there? Its just pretty much flat that go back some?

I was thinking of using a larger diameter pole or "H" beam type galvanized "posts".
The "bank" I'm holding back is about 2'6" to 3'.
There is a company that sells "Surewall" - this is the sort of thing I'm looking at now.
The problem with Surewall is ... not sold in the US.