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iowa
07-26-2007, 07:55 PM
Anybody do it? Everybody swears by it here.

mrusk
07-26-2007, 08:08 PM
Every job.

greg1
07-26-2007, 08:39 PM
Always! You'll sleep better at night.

PerfiCut L&L
07-27-2007, 07:11 AM
We better be. Keeps the aggregate from mixing, drains from clogging, and wall from failing. If your not, then your destined for failure sooner or later.

Dreams To Designs
07-27-2007, 07:28 AM
It also keeps any sediment from flowing through the wall and staining your beautiful wall installation. I always recommend a very free flowing fabric to allow as much water through, but to contain the sediment.

Kirk

mrusk
07-27-2007, 04:39 PM
And fabric under your base always

cgland
07-27-2007, 08:42 PM
Actually, NCMA does not require fabric behind walls, but if an engineer specifies it you should always use a non woven fabric like the junky stuff from Home Cheapo. We use it about 50% of the time based on the application and type of infill material.

Chris

Drew Gemma
07-29-2007, 12:47 PM
cg could you give me the breakdown on which fabric types to use for each application. I happen to like the woven fabrics for driveway applications but you say on walls they are a not recomended.

ChampionLS
07-29-2007, 02:26 PM
You should use a needle punched non woven Geotextile similar to "weed block fabric" (not the thin cheap crap with all the holes) The type that's usually gray and looks like a sheet of fiberglass. These fabrics resemble felt and provide planar water flow. They are commonly known as filter fabrics (although woven monofilament filtration fabrics exist). Typical applications for non-woven geotextiles include aggregate drains, asphalt pavement overlays, and erosion control.

Below, are a photos of non-woven filter fabric (good for walls and drainage)
and woven- good for soil wraps, and base stabilization (under the base for pavers)

MowingisMaddness
07-29-2007, 02:39 PM
What happens to the wall after the fabric clogs up from all that sediment you are keeping from coming through your wall?

PSUturf
07-29-2007, 03:54 PM
We use Mirafi N Series non woven fabric behind pre-cast and boulder walls.

cgland
07-29-2007, 05:00 PM
What happens to the wall after the fabric clogs up from all that sediment you are keeping from coming through your wall?

Once your fabric can no longer alow water to freely drain through it, you will start to get a buildup of hydrostatic pressures and ultimately failure of the wall.

Chris

MowingisMaddness
07-29-2007, 05:46 PM
But using fabric is what makes some of these guys sleep at night? Sweet dreams:)

cgland
07-29-2007, 08:46 PM
But using fabric is what makes some of these guys sleep at night? Sweet dreams:)

As the years pass and we learn more and more about the construction techniques of SRW's new ideas and thought processes come about. For example the need for fabric behind a wall. If you compact your infill zone properly and your drainage zone is adequate the need for a filter fabric is not needed because a well compacted soil will not tend to leach as much as an uncompacted one. So for the most part, on all of our cut walls we do not use fabric unless called for by an engineer. Plus, it's a huge PITA to install a filter fabric in conjunction w/ geogrid.

Chris

ChampionLS
07-29-2007, 08:46 PM
I think your missing the point- It's ok to put fabric behind the wall block to keep fines and organic matter away from the face of the block. This is especially beneficial for tumbled walls, natural walls or any wall where there are open crevices for sediment to filter through. You should NOT use fabric between the drainage aggregate and the retained soil mass. This can cause clogging and failure of the drainage aggregate to work properly. The only specifications where filter fabric was specified that I know of was on a shoreline retention project that was subject to tidal waters and erosion from boat wakes. In this situation, you would have continuous water behind the wall twice a day.