Replies

1. 
   dude | Jun 24, 2005 08:56am | #1

   are you talking about adding a addition to a exiting house or are you trying to  lower the ground in your crawl space

1. 
   svendsen | Jun 25, 2005 06:12am | #2

   i am adding an addition to an exsisting house and the existing house is built on footings but only has crawl space. so the delima is to add a basement and the main floor i need to be able to remove 9' aprrox for the basement but than the footings against the walll where the additions is going to be , will be dug down the 9' next to the existing footing which than about 4 or 5 feet will be dirt so the way we are going to try this is dig down the 9' and poor a 12'' wall about 8" away from the existingfooting and wall that way there will be that wall there to hold the presseure for the wall caving in. I HPOE YOU CAN UNDERSTAND THE WAY IM TRING TO TELL YOU THIS. LET ME KNOW

1. 
   dude | Jun 25, 2005 09:30am | #3

   I see from your profile you are in Minnesota so you would have a concern with frost heaving.

   How deep in the ground  are the footings on your crawl space section.

    The footings are  at the lowest point of the existing walls

   When dealing with 2 structures that are in the ground at different depths  they will tend to want to move at different rates and a 1/4" at the footing can translate into 2" at the peak of the roof thus the need to tie the 2 structures together all the way up unless you are on solid rock ,sometimes this is the reason for a crawls.

   Getting  a opinion from several  foundation contractors on how to  go about this in your area  would be a good place to start  and can't hurt you .

   I have  seen this  foundation situation a number of times  where it  wasn't done  right and the  solutions are quite  expensive if done after the fact.

2. 
   piko | Jul 13, 2005 09:25am | #4

   Without knowing how long the new reatining wall will be I can only but add one BIG warning - to add that new wall at 8" away will require you to undermine the existing footings. This is unsafe. Go spend a few dollars on an engineer, we're not qualified here to give you an answer w/out knowing a lot of local soil conditions, codes, and other variables.ciao for niao

   To those who know - this may be obvious. To those who don't - I hope I've helped.