Retaining wall

[asylum575]

Thanks guys. I think I will do the blocks. I will get to free up some time during the summer when my wife is off(teacher) and she will watch the little one(17months) in the mornings before work. I start work at noon, so that can give me three hours every morning or so.
My plan is to pull some of the big rocks out, as they will serve well in the landscaping. The three big guys are rouchly 4'x2'x3'. The BX couldn't lift them, so i dragged and pushed them into position. Otherwise I will clean up the lower portion of the wall to dig a trench and set the first course below grade. The block I saw have the rear cleat, so I hope that's enough to hold. Not really crazy about pouring concrete, but I bet it's an easy way to set that first course level. I figure it would be a little under 2 yard, so I would probably form out any other concrete work that I want to redo and have one of those mix on the spot guys to come.

 

[patrick_g]

Thanks guys. I think I will do the blocks.

Otherwise I will clean up the lower portion of the wall to dig a trench and set the first course below grade. The block I saw have the rear cleat, so I hope that's enough to hold. Not really crazy about pouring concrete, but I bet it's an easy way to set that first course level.

I'm not knocking a poured footer (much) but... if the bottom of your trench is undisturbed earth (not recent fill and not sand or other other poor load bearing soil then trenching and compacting in some gravel will do a good job. The gravel will not retain water like a poured footer, is cheaper, lends itself to DIY since it doesn't have to be done all at one time.

A tightly stretched string with a line level (a buck or two) will make it easy to dig a level trench and easy to get the gravel level too. The cleats on the back of the blocks have worked just fine for me and give you an automatic spacing so the wall leans back pretty uniformly. If you are really worried about strength drive rebar down through the hollows of the blocks before filling with gravel. Don't just dump the gravel in but put a few inches in at a time and tamp it down. This will lock the blocks together, especially with the rebar and the individual blocks will not be able to move independently to get out of alignment over time.

If it were me, I'd invest the $ that I would have spent with the concrete guy in hiring some help with the heavy lifting.

Pat

 

[asylum575]

Thanks Pat,

The wall will be on a grade and a bit of an inward arc. That makes for alot of stakes with string to level. I've still got about 15 yards of 1 1/2 stone left over from my drainage projects, so I won't need much more stone.

 

[patrick_g]

Thanks Pat,

The wall will be on a grade and a bit of an inward arc. That makes for alot of stakes with string to level. I've still got about 15 yards of 1 1/2 stone left over from my drainage projects, so I won't need much more stone.

15 yds of left overs? You must have had quite a project. 1 1/2 inch should go in the hollows of the blocks (assuming yours has hollows) and compact down to help lock the blocks in place.

I forgot to mention (but you probably already figured that) the vertical rebar to help solidify the wall doesn't have to be very large in diameter to really stabilize it a lot.

Good luck on the project and remember to practice back safe lifting.

Pat

 

[CurlyDave]

...The wall will be on a grade and a bit of an inward arc. That makes for alot of stakes with string to level....

I bought a rotating laser level for about $400 a couple of years ago at Lowe's. A tripod and a grade rod were about $50 each. It works great, especially compared to string and line levels. A DeWalt version of a similar level is now $360.

There is a reason why the the pros use this kind of equipment.

 

[Gizmo2]

...The wall will be on a grade and a bit of an inward arc. That makes for alot of stakes with string to level....

I bought a rotating laser level for about $400 a couple of years ago at Lowe's. A tripod and a grade rod were about $50 each. It works great, especially compared to string and line levels. A DeWalt version of a similar level is now $360.

There is a reason why the the pros use this kind of equipment.

Is it hard to see the line in the day light?

 

[asylum575]

Picked up a laser level and tripod at Harbor Freight over the weekend. They had their sidewalk sale going on. Can't wait to try it out.

 

[patrick_g]

Some of the laser levels are really hard to see (or impossible) in sunlight. They sell special glasses to enhance the contrast. These glasses pass the light in the color of the laser and stop a lot of the light of other colors. This increases the signal to noise ratio a lot and helps you see the laser light in sunlight.

Better are the laser systems that use a laser detector on the "GIANT RULER" you use to check grade variances. These work with lasers that put out light you can't see and indicate how much above or below your selected datum something is. These work way better but do cost more. I have NEVER had a professional show up at a job site with a visible laser. They ALL have ALWAYS had the kind with the laser detector that emits tones so you can know if you are above or below or right on.

I have used a "water level" and have added garden hoses to give me hundreds of feet between the fixed and portable ends of the level. Yeah, I know both ends are portable but working alone or with untrained help is is easier to just leave one end bound to a stake. This does as good of a job as the most expensive laser system and has NO PROBLEMS with bright sunlight.

Pat

 

[CurlyDave]

Is it hard to see the line in the day light?

Typically the laser head comes as a kit with a laser detector which beeps when the laser beam hits it and has a display which allows very precise measurements.

The "GIANT RULER" is called a grade rod or a story rod.

 

[patrick_g]

The "GIANT RULER" is called a grade rod or a story rod.

That is what I thought but to be sure I looked it up and didn't get full agreement.

"A pole cut to the exact specified height from finished floor to ceiling and used as a measuring device in the course of construction. Also known as story pole."

Well... FORGET THAT!!! I'm gonna call the big ruler a story pole like I did before.
Pat