| Click to Post a New Message!
Page [ 1 ] |
|
|
|
Retaining wall backfill step building questions
Well, from my point of view, the biggest issue you have is the clay, luckily however you don't also have the frost problems we do, that is a wall-killer combination. I can't think of a problem more destructive than frost heave.
That being said, your three priorities should be drainage, drainage, and drainage, in that order. 
I wouldn't use the geotextile fabric anywhere except to protect and isolate the gravel from the native soil and around the drainage tile. Get the drainage tile that comes wrapped in fabric.
I've had good luck building a regular wall then then building a conventional set of stairs out of cedar that sit on a concrete footer at the bottom. It ends up a LOT cheaper and looks, IMHO, nicer than concrete steps do. Too much chance of built in concrete steps settling and causing uneven footing for those using the steps IMHO. Even a very slight difference in steps is very noticeable to even the average person using them. If the wall shifts wooden steps can very easily be re-leveled in short order, concrete not so easy.
Best of luck.
|
|
 Add Photo
Bookmarks: |
|
| |
|
Retaining wall backfill step building questions
|
Quote:
|
When building a gravity wall without geogrid the mfr. instructions say to construct the back of the wall with a drain and compacted gravel all wrapped up in landscape fabric.
|
|
As long as you have a continuous layer of gravel, protected by an also continuous sheet of geotextile fabric there cannot be any hydraulic force against the wall.
Despite what the women think, gravity is a good thing! 
With a proper installation any seepage behind the wall goes straight down through the aggregate and into the weeping tile, if there is more water than the weeper can handle it will just run through the gravel beneath the wall itself and back to surface in front of the wall.
It is very important BTW to make sure that the weeping tile either comes to daylight (i.e. runs downhill underground to a place where it appears) which is preferred, or at the very least has a catch basin (or several) along it's route so that you can check for silt coming out, and backwash it if necessary to keep it open and flowing.
Best of luck.
|
|
Add Photo
Bookmarks: |
|
| |
|
Retaining wall backfill step building questions
A little over-kill IMHO, but it shouldn't move any, that's for sure!
The other thing you should do is run 2 separate drainage tiles side by side when you build the wall. If there is a lot of water it will help a lot, if not it's a cheap insurance policy.
I've seen some really lovely landscapes ripped up for no reason other than trying to clear a blocked pipe, or replacing a broken wire. A second strand of wire, or a second run of drainage tile costs pennies to put in when the hole is open originally compared to the cost of replacing a failed one later.
Also, if it's possible, and not too unsightly, try to put some method of getting the higher end of the drainage tile to daylight also. They sell a variety of fittings for this, or you can just get a few feet of ABS pipe a little bigger than the drainage tile, and cement a threaded fitting and screw cap on one end and stuff the pipe in it bringing it then vertically to the surface. This will be invaluable later on if you ever want to flush the drainage tile out, you just open the end and stuff a hose in it and let 'er go!
Best of luck.
|
|
Add Photo
Bookmarks: |
|
| |
|
Retaining wall backfill step building questions
Ken, first off, if possible try to resist using the drainage tile to get a 2 for 1 out of it, while a (presumably) small roof of a shed likely won't do much harm, you are trying to dry the area out, not introduce MORE water. Remember, anything you pour in the high end has to travel the full length of the tile to get to daylight, more than likely it will be absorbed by the soil below the wall long before it gets to the far end.
As for the stone, if the 'pea gravel' they sell is round I'd go for the crushed stuff (3/4" and less), round things don't pack as well as stuff with sharp edges, but roundish stuff does let more water pass since it leaves bigger gaps too.
The most important is to get something as 'clean' (no sand or other soil or contaminants mixed in with it) so you don't start off the process by dumping a load of stuff in there that will clog the drains from the get-go.
If you want it well packed spend a few bucks and rent a gas-powered tamper, it will save you a lot of grief down the road.
Best of luck.
|
|
Add Photo
Bookmarks: |
|
| |
|
Retaining wall backfill step building questions
Not that I want to screw up a perfectly planned wall by doing something silly like thinking, but here goes anyways.
Your caption on the picture "A retaining wall is being built here to keep the shed from sliding down the hill!" got me thinking.
If the main goal is to stabilize the building, why not just build a much smaller wall but deeper that runs maybe 4-6' out from the shed and around it enough that the shed is standing on flat land?
We do this all the time where we need something along side say a driveway, like a garage, and we need it to match grade to the driveway, but the ground where we want to put it falls away, so we just build a 3 sided wall out from the driveway and a few feet wider and deeper than needed, then put the building on top.
It doesn't take a lot of stable soil to keep a building secure.
Best of luck.
|
|
Add Photo
Bookmarks: |
|
| |
|
Page [ 1 ] | Thread 156677 Filter by Poster:
2 | 6 | 5 |
|
()
Picture of the Day
candoarms
Unanswered Questions
Active Subjects
Hot Topics
Featured Suppliers
|
Gas Generator Weather Protecti
09-16-2008, 11:37 
Digg It 
Del.icio.us