Replies

1. 
   SamT | Sep 29, 2007 12:18am | #1

   For waterproofing, I like Xypex. If you want suspenders with that belt, use a paint on system.

   For a drainage system in your locale, just use a super sandy backfill.

   SamT

1. 
   madmadscientist | Sep 29, 2007 12:43am | #2

   The last foundation he did for me had a bitchuthane <sp?> membrane applied to the walls.  But I have heard that the membrane should cover the walls, down to under the footings and tie into the moisture barrier under the slab?

   We are doing french drains along the perimeter of the foundation with two under-slab drain lines also.  These will dump into a sump pit that will get pumped to the street.

   How's that sound?

    

   Daniel Neumansky

   Restoring our second Victorian home this time in Alamdea CA.  Check out the blog http://www.chezneumansky.blogspot.com/ 

   Oakland CA 

   Crazy Homeowner-Victorian Restorer

1. 
   SamT | Sep 29, 2007 02:36am | #3

   MM,You said that you have super sandy soil. Meaning that if you left the garden hose turned on overnight, there would not be a puddle?In that case any drain tile you set will never see use until the water level rises from ~6' to above the tile. Then the sump would be already full and you would have to pump the whole ocean out.I have used that under the slab wrap up the walls waterproofing before on a containment vessel. We poured a rat slab because the soil was so waterlogged it was the consistency of stirred jello. Then we laid a large enough sheet of 20mil to cover the entire area and fold up the walls.You said:
   "To refresh, crumbling brick foundation with rat slab slightly below grade being replaced with concrete foundation and slab"Will this be a basement or rat slab and foundation walls?SamT

1. 
   madmadscientist | Sep 29, 2007 04:19am | #4

   Will this be a basement or rat slab and foundation walls?

   It will be the bottom floor of the house a real slab with a real  brick foundation.  The top of slab will be about 2' below grade so not really a basement I don't know what to call it.

   Daniel Neumansky

   Restoring our second Victorian home this time in Alamdea CA.  Check out the blog http://www.chezneumansky.blogspot.com/ 

   Oakland CA 

   Crazy Homeowner-Victorian Restorer

1. 
   SamT | Sep 29, 2007 06:06am | #5

   I don't see a slab sitting on 4' of sand needing a perimeter drain unless you're sitting in the middle of a seasonal stream.I do see a water vapor problem, in that you're only 4' above the Bay. I would recommend a vapor barrier under the slab.SamT

2. 
   brownbagg | Sep 29, 2007 06:44am | #6

   if you dont put a vapor barrier with sand as a subsoil, the concrete will crack like crazy within hours of placement.BOB is always right, ALL HAIL BOB

2. 
   BillHartmann | Sep 29, 2007 09:38am | #7

   If you do wrap around the vapor barrier under the footing then it can't be used as a Ufer ground.The I don't remember the exact wording, but basically the NEC wants a ufer if it is practical to do. Clearly in an existing building it would not be practical to add one.And if there are foundation enegineering reasons to not have one that it is not "practical".While UFER grounds have been around since WWII having the primary ground electrode is fairly new.So if you if you want to do that be sure and pass it by the inspector first.Otherwise have the electrican work with the foundation contractor to make the connection..
   .
   A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.

1. 
   Matt | Oct 01, 2007 02:26am | #8

   Just as an FYI, for example, here in central NC, UFER grounds are not commonly used in residential construction.  Here, we use driven ground rods.  And yes, we go by the NEC.  I don't know what the book says, I just know there are not used here.

2. 
   caseyr | Oct 01, 2007 06:40am | #9

   Bill -
   Any indication of how much of a slab foundation can be unlayed with an impermeable barrier and still be acceptable as a Ufer ground?

1. 
   BillHartmann | Oct 01, 2007 06:50am | #10

   IIRC the code talks about 20 linear feet of connected rebar or wire encased in concrete and in contact with the earth..
   .
   A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.

2. 
   caseyr | Oct 02, 2007 06:37am | #11

   BillThere is an interesting thread over at the International Code Conference on Ufer grounds and on the grounding i general. You might want to check it out if you haven't already.http://www.iccsafe.org/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=11;t=000932;p=2

3. 
   madmadscientist | Oct 03, 2007 12:40am | #12

   Not that I mind that this discussion has gone round the bend.

   I have an actual question.  What is a reasonable spec as to how level the new slab should be?  In the finished portions of this level I am probalby going to use a dri-core type product on the floor and would really like the floor to be 'level' so I don't have to deal with the shims...

   Daniel Neumansky

   Restoring our second Victorian home this time in Alamdea CA.  Check out the blog http://www.chezneumansky.blogspot.com/ 

   Oakland CA 

   Crazy Homeowner-Victorian Restorer

4. 
   brownbagg | Oct 03, 2007 01:15am | #13

   1/8 inch in 20 feet flood the slab with water,find a puddle, stack two nickels on top of each other, if Thomas jefferson drowns, it fails.BOB is always right, ALL HAIL BOB

5. 
   madmadscientist | Oct 03, 2007 01:33am | #14

   Thanks Brown I appreciate it.  Sounds reasonable to me, but what the heck do I know.  Hopefully at the end of this I'll have two nickels to rub together!

    

   Daniel Neumansky

   Restoring our second Victorian home this time in Alamdea CA.  Check out the blog http://www.chezneumansky.blogspot.com/ 

   Oakland CA 

   Crazy Homeowner-Victorian Restorer

6. 
   DonNH | Oct 03, 2007 05:09am | #15

   Didn't have 2 nickels - used a dime instead.  Everything's bad . . .