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View Full Version : small problem, could be big, need expert opinions


cedarcroft
07-12-2006, 04:39 PM
I just built a 75' x 4' retaining wall (using keystone compac block) that the radius feeds into a future driveway. the tail end of the driveway grade goes up about 1' from the base of the wall at the radius, so there is plenty of block buried. I put the drain pipe at the 3rd course and dumping out to the proposed raised planter box as per the customer. I went back this morning to install the cap and the customer tells me that he decided to pave right up to the wall and there will be no raised planter box. that leaves me with half a course buried at the corner and a drain pipe dumping to the driveway half way up the wall. do you people think this will be a problem?
I am concerned about hydrolic pressure at the base below the drainage.
if this is a big problem, WTF am I supposed to do?!?!?!? tear down the wall? drill holes in the base? change the name of my company and wear sunglasses around town??? I am annoyed and pissed about this.

D Felix
07-12-2006, 05:43 PM
Depending on the manufacturer, the drain pipe needs to be either behind the base course, or behind the second course.

You put the drain pipe in too high...

As long as your base gravel is left undisturbed during paving excavations/operations, you will probably be OK.

Even though you put the pipe in too high, I'd still do a CYA, and have them sign something stating that the wall was designed and installed to have the driveway a foot or more away, etc, etc, etc, and if that is not adhered to, then you are in no way liable for any future repairs....

We've got a wall like that at work, it was put in a few years ago, concrete driveway poured right up to it. No problem, except that the driveway was excavated and disturbed the wall base. Now there's a 30-40' section that's tilting the *wrong* way and will have to be torn down and rebuilt....

cedarcroft
07-12-2006, 05:52 PM
I understand the pipe is too high. thats the problem. if it was any lower the water from the other side of the wall would not be able to get to the drain, which was set high to be above the raised planter that would have buried my first two courses. anyway. this sucks.

D Felix
07-12-2006, 06:10 PM
I guess I fail to see why something on the front side of the wall would affect the drain pipe placement, other than where it outlets.

The wall will collect water behind it. No water should collect in front of it; if it does, your grade is not correct.

A raised planter bed in front of the wall should have had it's own drain pipe that either outletted on it's own, or somehow tied into the one behind the wall.

Chances are, the drain pipe being too high will be a non-issue. As long as you have adequate drainage stone behind the wall, the wall should be porous enough that it will drain out through the wall. That's the beauty of SRW's. Very seldom, if at all, will you see water draining out of the pipe behind an average wall....

Mike33
07-12-2006, 08:38 PM
If im reading the thread correct, not a perfect picture but if you have a deep enough footer on a base that will perk it could possibly take the water also. I did a wall last week where i had to build a 24'x4' wall between 2 walls. Steep slope above but the footer area was shale and drained real well we built on 2' of gravel with no drain thru the wall and i felt good about it. I normally dont do this but after we excavated the homeowner ran a new water line in and they broke it off my footer started filling with water then perked perfectly. My wall was not the best case sceniro any way we were joining an old thick cut stone wall and could not join to it perfectly any way. This job was in a real **** hole end of town where the city paid for it by grant money.
Mike

cedarcroft
07-12-2006, 09:51 PM
I guess I fail to see why something on the front side of the wall would affect the drain pipe placement, other than where it outlets.

The wall will collect water behind it. No water should collect in front of it; if it does, your grade is not correct.

A raised planter bed in front of the wall should have had it's own drain pipe that either outletted on it's own, or somehow tied into the one behind the wall.

Chances are, the drain pipe being too high will be a non-issue. As long as you have adequate drainage stone behind the wall, the wall should be porous enough that it will drain out through the wall. That's the beauty of SRW's. Very seldom, if at all, will you see water draining out of the pipe behind an average wall....

The drain pipe exits the wall in the third (of 6) course. it was set there because the customer was going to bury the wall in that area up to the top aof the 2nd course to make a raised planting bed. now there will be no planter and the driveway will come up to the wall. soooooo...there is a drain hole in the middle of the wall and I am concerned aesthetically and also concerned about the water building up BELOW the drain pipe against the wall and eventually pushing it out.

D Felix
07-12-2006, 10:02 PM
The Compacs don't fit together tight enough for the water not to drain through the face.

Is there a large source of water runoff on the top of the wall?

If you are concerned about aesthetics, get the customer to pay the couple hundred to take apart the few feet of wall to get to the drain and replace the drain with whole block....

Even though there was to be a raised planter bed in front of the drain, I still fail to see why you thought you needed to install the pipe so high....?

mrusk
07-12-2006, 10:07 PM
Maybe just put a fancy drain end on the pipe coming out of the wall. Honestly, i have never seen any water come out of a drain pipe.

Matt

cedarcroft
07-13-2006, 05:44 PM
Dave Burton is a ***. Forza Italia '06!!!!!!!!!!