i’m jacking up my house and excavating a basement. old timers say my area used to have a pond nearby. 18″ down is blue clay and the water just sits on it. mine’s the old farm house. going for a mono-pour footing & stem wall. i’ve been told that cetco bentonite clay products are the bulletproof ones, plus a perimeter fdn drain to side sewer of course. has anyone used these products? 1. paint-on “zypex” waterproofing, 2. then “voltex” bentonite mat, 3. then “aquadrain” composite dimple board, 4. then “RX101T” waterstop between slab and stem wall.
anyone have installation, backfilling tips? i so want a dry basement.
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Greetings todd,
This post, in response to your question, will bump the thread through the 'recent discussion' listing again.
Perhaps it will catch someones attention that can help you with advice.
Cheers
"I can't say I was ever lost, but I was bewildered once for three days."
Don't know how much help this will be, but there are a number of short videos under the category of "best practices" for the building trades found at http://www.hgtvpro.com/hpro/pac_ctnt_ihdr/text/0,,HPRO_20976_28891,00.html?cat=0
One particular set of videos deals with the installation of foundations in all respects.
You might want to check them out to see if you get any ideas.
Griff
thank you . i will check them out
We did the same thing as you as far as jacking up the house and replacing the foundation in a clay-rich area. The one advantage we had is that our excavation barely came into contact with a sand layer 10' below ground (everything else is/was hard clay). Thus, some areas of the foundation ought to drain well, while others still enjoy 6" to a foot of clay separating it from the sand below.
That's still better than our neighbors who needed a drywell on their property and only found sand 16' down.
Anyway, I found the "From Pros for Pros" series of books from Taunton to be an excellent primer on where to start. They have one on foundations, another on concrete work... Next, I'd have a look at installing a french drain (well-wrapped in peastone and geotextile to keep the clay out) and Rub-R-Wall.
We had standing puddles of water outside the foundation walls for weeks during construction with nary a damp spot on the inside, even around cold joints. So, I highly recommend the combination of Rub-R-Wall and XPS on the outside to minimize the possibility of water getting in and dealing with the insulation at the same time. Having covered XPS on the outside is the way to go, as shown at buildingscience.com.
i'll check out rub-r-wall and xps. i've dug (2) 4 foot deep test wells and water has been standing in them at various depths depending on recent rains all spring. i guess the water hits the clay and sits...sloooooowwwwwly percolating out. in seattle, the days of dumping foundation drains into the sewer line are gone. they wanted me to do a dry well (read wet well in clay), told them i couldn't..then they wanted me to trench across my street to pump to a ditch and culvert 12" below grade...no....how about pumping to a cistern w/ overflow to the sewer? sorry...then they were going to have me catch basin, pump and meter me to the sewer line. don't think so. i found a catch basin at a street around the corner and down the hill from me so i need a 4" tight-line and some easement agreements from my neighbors. gravity always works.
i suppose i won't know how much clay i have until we dig. suppose there is sand down there somewhere but my struct engnr says half of downtown is on blue clay.
thank you for your help.