View Full Version : Looking for some advice for leveling work and cement blocks

04-02-2010, 05:31 PM
Hey all,

I hope I put this in the right forums, and if I didn't, please move it to the appropriate section. Basically, I have a customer who has a bunch of cement blocks of varying sizes that surround a pool pump, and extends her patio. The customer explained that about every 5-10 years she has to have them leveled, as they need to be now. I am basically looking for some advice on how to go about doing this.

I'm not completely dark on this process, but I want to make sure I'm not missing anything here - I am no expert on this kind of work (haven't tackled a problem like this before). To begin, dig about six inches deep under the blocks, and fill about 4 inches with Paver Base Step 1. Next, fill 2 inches with leveling sand (Paver Base Step 2). Wet it, stamp it down, replace the blocks... done deal.

Am I missing anything here? Also, would you recommend using patio edgers to keep the materials from shifting around? I want to create about as permanent a solution as I can, keeping in mind she doesn't want to pour cement. To wrap it up, I figure I would replace the stone surrounding the blocks with something similar, and place weed-fabric underneath it to help block out weeds.

I enclosed some pictures to hopefully give you an idea of what I'm working with here. I need to try and figure how to estimate the labor on this, 2 guys working... any tips here would be greatly appreciated. This is all new territory for me, but I don't think it would be beyond my skill set. Thank you very much in advance.

- Marinucci

04-02-2010, 06:27 PM
This is what I would want to do: 1) Get everything out of there, pull the slabs, rake out and discard all the stone and soil. 2) dig enough to accommodate the final grade ie. sub-base and paving material. 3) Run over it really good with a plate compacter. 4) I might consider a fairly deep hole filled with crushed stone in the middle, as a dry well (Looks like freeze/thaw heaving to me). 5) Continue as you said. 6) Try to find a way to extend that blasted down spout out of there, (I'm sure that thing is dumping a lot of water in that corner. Try to see if you can put some even sized paving material there, I don't think all those odd sizes are any help. I think the idea is to keep the openings between slabs as small as you can. Then fill in with some course washed sand.

Just my vision.

04-03-2010, 01:20 AM
Hey Betmr,

Thank you for the speedy response. I can't help but laugh while I write this, simply because I am horribly ignorant on this matter. Excuse the naivete, but I'm going to need some further explanation if you can, in what you mean and how to do what you have said. If you could dumb down a few steps for me I'd appreciate it greatly.

I pretty much had no clue what you were talking about on numbers 2 (don't know what you mean by "to accommodate the final grade i.e. the sub-base and paving material), 3 (what's a plate compactor, how do I use one?), and 4 (don't get that one... at all). After having done these steps, then I continue on to put down 4 inches of Step 1, and 2 inches of Step 2 on top of that?

I agree with step 6, you are very observant. I wouldn't have picked up on that, and I would have to agree that freezing and thawing is probably a big part of the problem here. I'll be sure to point that out to her. Filling it in with coarse sand, yes I've seen other block projects have that in between... I don't know why it's there, but it is (lol). Another good idea, thank you.

Again, thank you for your time, and I apologize for making this difficult for you.

- Marinucci

04-03-2010, 02:44 AM
First let me express that I am not the total expert. That said I will explain. Explanation of #2 First you have to establish your Finished grade. That is the surface of the job when it is finished. You are estimating 4" sub-base (Step 1)& 2" finish base (Step 2). Let's just figure those slabs are 2" thick. All this = 8". That means you dig out enough soil so the soil surface is 8" below where you want the top of you slab surface to be when you are done. #3 A plate compactor is a machine you can rent. You often see it when guys fill pot holes. it's a heavy machine with a flat plate on the bottom, driven by a small engine, it vibrates rapidly, compacting the soil underneath, as it vibrates you can easily pull it around over the surface.This will help to minimize future settling. You compact the soil before adding your base material. #4 A dry well is a hole made so it will not fill in with soil. Surface water can go in it, an down below the frost line, and has time to soak into the soil, without sitting on the surface and freezing. In cold weather, if water has no where to go it freezes, and expands There-by pushing anything & everything out of it's way. (I've always had this little saying, there is nothing stronger than water. It can erode mountains, heave roadways & burst Iron pipes.) So if you want one, you dig a hole, line it with fabric and fill it with any nature of stone broken up concrete, broken cement blocks, what have you. as water seeps through your slabs and base, it makes its way down into the dry well, then seeps down into the soil, minimizing freeze. Lastly the sand in the joints, is like your Grout. and it allows the water to flow through freely.

To me that down spout is an important part of this project. You would be surprised by how much water is displaced by that roof, and a good portion of it is coming right down in that corner.

Like I said, I don't want anyone to think that I'm thinking I'm the expert. These are some things I know a little about, and I'm just tyiing to help. It's not an easy job to take on by yourself, there is a lot of labor in that.

04-04-2010, 03:57 PM
That made things much clearer to me. Thank you very much Betmr!

- Marinucci

04-04-2010, 07:09 PM
I'm not sure if that fence is going to interfere with you grading the slope so water pitchs away from the house. How close is the pool to the fence? Does the yard on other side of fence belong to your customer? You could use geofabric or filter fabric to help stop weeds. The slab under pool pump looks uneven and cracked. Soil close to a foundation doesn't normally freeze from heat loss or heat at foundation,it will freeze a few feet out. If you really had to add a drywell, we use Infiltrator plastic chambers. plowking

04-05-2010, 10:44 AM
The fence is probably about 10-12 feet from the fence, which separates her house from her neighbors. I was planning on grabbing one of those two fabrics to help stop the weeds, they seem to work really well when they lie under stone. Infiltrator plastic chambers? I'll remember that. Thank you.

- Marinucci