Replies

1. 
   Guest_ | Jun 24, 1999 03:04am | #1

   *
   Chris,
   I'm sure someone here will be able to help, but it would be good to have as much detail as possible. ( we don't need to know what colour your undies are though )

1. 
   Guest_ | Jun 27, 1999 08:59am | #2

   *Chris,W.R. Grace make a product for use under slabs called prepruf (sp?). It adheres to the back of the slab as it cures to form a waterproof membrane. Something like it may work for you. Call Grace; I found them very helpful on my last project.Jerry

1. 
   Guest_ | Jun 27, 1999 11:38pm | #3

   *Chris,Ditto Mark....I need more information.By underpinning do you mean a concrete foundation?Down here the underpinning is the wood joist system that spans the pier and beam.If that is what you mean, you damn sure don't want that below grade.Call back.Ed. Williams

1. 
   Guest_ | Jun 28, 1999 01:52am | #4

   *I'm with Mark on this one. Not much information for this type of situation.I have to know how you intend to form the back or buried portion of the wall. I assume, you are pouring the wall and can't access it from the outside because of some structure or whatever.If you intend on using a single wall form and use the dirt as the back form, you may want to put a sheet of poly against the dirt first.But as Mark said, fill us in first.Gabe

2. 
   Chris_Pinkerton | Jun 29, 1999 08:31am | #5

   *
   Ok guys I don't know how to make it much simpler. I've got a 10 inch unit masonary wall going five feet into the ground around an attached garage. The inside of this garage is going to become part of the basement of the addition. I've got a 18x4 footing at the bottom of the blocks and the footing is 46 inches above the level of the new basement slab. Underpinning it is a breeze, but, there is no way to dig on the outside of the wall to apply waterproofing. I can do as Jerry said and put a membrane on the back of the form (ie the dirt!),but I can't figure how to join it to the exising foundation. Does that help?

3. 
   Guest_ | Jun 29, 1999 06:35pm | #6

   *
   Chris,

   Let's see if I have this right. First of all you are dropping the inside elevation of the garage by at least 46" to match the existing and you are underpinning the entire perimeter (3 sides) with a poured concrete wall, formed on the inside only.

   Apart from the obvious drainage problems and attaching it to the existing system, not to mention the part about the impossibility of trying to get the membrane up and over the footing that was probably never designed for this modification and is completely encased in dirt, underpinning will not be a breeze.

   You NEED an engineer's help on this one, before someone gets hurt. Underpinning will have to be phased in sections to prevent the wall from collapsing, Waterproofing will have to be done from inside.

   Just one opinion,

   Gabe

1. 
   Guest_ | Jun 30, 1999 06:01am | #8

   *Chris,Listen to Gabe.Ed. Williams

4. 
   Chris_Pinkerton | Jun 30, 1999 06:01am | #7

   *
   Guys! I need help! I'm about to underpin an exterior wall on a house from the inside. Problem is this. How do I get the waterproofing on the outside if I can't dig out there. Has anyone done this before?