[Digger Dan]

First post on the forums. Looking to tap into the expertise I've been finding here on GTX...

I'm removing an old porch's decking (hopefully keeping the existing roof) and pouring footers for the two support posts. There's a steep grade (rises 10 feet after running only ten feet) behind the house that needs to be retained, as the existing wall is about 40-50 years old, and has begun to fail. There will be 2 levels included to remain under the 36" height required by code in my borough. I need to rebuild the concrete entrance around a bilcodoor (the old concrete just crumbles when breathed on too hard). I'll finish things off by putting in about 400sqft of pavers in the form of two patios and a new walkway along my property line.

The difficulties I have anticipated thus far are as follows:
1)There is no way to put ANY heavy machinery into my yard. Only have 24" between my house and the neighbor's place, with no accress from the rear of the property either. All work will be done by hand. Anyone know of an excavator that could slip into that gap?

2) The mo-mo at my home supply store didn't know what it was. He kept directing me to their silt fences.Can someone post a picture of geogrid so I can show him what I need?

3) I'm anticipating a cost of about $5-7 per sqft for my paver project. Sound about on target to you guys/gals?

4) I'm considering my hardscape options for the retaining wall, and I really like the idea of a cinderblock w/stone veneer (we have a yard full of awesome stones for the face of the walls) but I'm concerned about structural integrity. Not sure what zone I'm in here just outside Philadelphia, PA. Would pouring a reinforced concrete footer with 4" perforated PVC , behind it for drainage, using geogrid and then filling the cells inside the blocks with more reinforced concrete work for a 36" wall? We're holding back a significant hill, so I want this wall done with overkill upon overkill.


Many gracious thanks for your advice, input, etc. I'm hoping you guys can keep me out of the local bell tower!!

[Stonehenge]

Without seeing your situation I'm having a hard time understanding much of what you've said. However, here's what I can tell you:

1) I only know of one 24" wide excavator, and he brushes his teeth in your bathroom at night.

2) I don't know what a mo-mo is. And I'm not sure what you wanted a mo-mo to know, unless you're talking about geogrid. If you are, you won't find it at the big box home improvement stores. Also, geogrid is used in gravity walls, which a CMU masonry wall over concrete footing is not, so a mo-mo not knowing what it is isn't really an issue. Google Tensar, Mirafi or Strata, or just the term geogrid. You'll find a picture you're looking for (but you won't need for a masonry wall).

3) I don't know what your material costs are, so it's hard to say. Take the price of your pavers (add about 20% for waste/mistakes), add in the cost for 3 tons/100sqft crushed stone, polymeric sand at 50# every 100sqft (varies by paver being used), edge restraint and compaction equipment rental, plus any tools you might need to buy, and you'll have your cost for your patio.

4) Since it's 10' high and it sounds like you have little to no experience, you should call an engineer to design the specs for the wall build for you. Might cost you $1,000 or more, but it could save you many thousands down the road.

In my opinion, this would be a project outside the safe scope of a DIY'er. My $.02, anyway.

[papercutter]

I second the advice to hire an engineer. It's really not a lot of money when you consider the safety and peace of mind you're buying for the price.

[Lanelle]

Also agree with the advice given.
If you are trying to build low walls to avoid getting a permit, remember that there has to be a space that is 2x the height of the wall between the walls (6 feet in your case). But that doesn't sound very practical from the info that you gave. Trying to avoid getting a permit in this situation sounds foolish. Hiring an engineer is a wise way to protect your investment (house).

[Stonehenge]

Lanelle - I'm not 100%, but I think that spacing requirement is if you want to consider each of the walls to be independent (engineering-wise). If they are closer, they can still be built, they just must be engineered as not being independent of each other.

But whatever the case, this one has crashing walls and injured humans written all over it. I think an engineer should be called in.

[Lanelle]

Exactly. And if they are not independent, they must be engineered and permitted.

[Digger Dan]

Sounds like an engineer is the way to go. I've tried to get estimates already, but after calling 27 different companies, only 4 showed up when they said they would, and every single one looked like he just got out of jail and would offer no warranty on their work. Kind of a red flag. That's why I wanted to get it done myself. I've got 9 weeks off from work coming, so I was hoping to do it myself.

[saslandscape]

Good grief I wouldn't tackle this as a DIY project! Check out Angies List or something that shows landscape companies ratings. This project is extremely complicated and the last thing you want is the wall to crumble while you're on top of it. I had a client who was in your situation that I designed the walls for, and thank goodness they hired a landscape company to install the work instead of doing it themselves. They also only had 24" of space for access and a steep slope. Estimate came at $70,000 (but included patios and stairs). Good luck!

[Digger Dan]

Just a little update.

Decided to scrap the upper patio, and just reinstall new porch roof posts, 130sqft of pavers and remortar the existing wall. Ain't what I wanted to do, but the original project was just too much to get done within the time constraints. I'll post pics once I figure out the new camera.

[Digger Dan]

Now that we've reduced the project to a more reasonable scale, we're moving right along. I've managed to repair some of the cracks in the mortared stone wall you see in the far background, and now I'm concentrating on my alleyway. The main focus of my consternation is this stinkin alleyway. Wall on the right is leaning hard into my yard and will need to be replaced next season. Sure would love to have a word with the guy who put THAT in...

But anyway, I need to engineer a means of restraining the patio while allowing the drainpipe to pass below without compromising the strength of the restraint. I'll need to do it twice, once in the background where the 2 CMUs are sitting, and again toward the bottom of the photo.

I was going to cement rebar into the existing concrete and lay the CMUs onto them and cement them into place, then top with some limestone slabs.



Thoughts, Suggestions?

[Stonehenge]

I'm not understanding what you're wanting to do. What patio are you retraining? And what are you restraining it from or against?