I am building a Durisol ICF house in Ontario Canada.  It's slab on grade and the north wall is backfilled to 5 feet. Soil is predominately sand and there will be good draining.  I have had conflicting advice on the best way to waterproof the below grade wall.  This wall encloses living space (e.g. not a basement), so I want to be as certain as possible that I have provided the best defence against water and hydrostatic pressure. 

Any advice is appreciated!

Lynelle

Posted By [email protected] on 20 Aug 2010 11:13 PM
I am building a Durisol ICF house in Ontario Canada.  It's slab on grade and the north wall is backfilled to 5 feet.

By any chance are there going to any bedrooms in the north part of the house where the backfill is? If so, do they extend along the side walls far enough to allow emergency egress windows to be placed in the side walls? I don't know what building code you have to follow but the International Residential Code requires an emergency egress window in every sleeping room and the sill of that window can be no more than 44" above the floor. This means you can not have 5' of fill against a wall and have an egress window in that wall.

On;y storage/utility are in the first floor north wall. There is a bedroom on the 2nd floor, with one east window that is 24" above floor, so I am covered.

Any ideas about the waterproofing?

Thanks!

Lynelle,
I am not an expert on Durisol. However, I have chased a lot of water on regular ICF, poured concrete walls and cmu(concrete block) walls. The process is always the same. Stop the water from entering the wall, AND give it an easier route to follow. Generally, I accomplish this with a peel and stick bituminus membrane, followed with a drainage plane, lots of drain tile and gravel. Even if your soil does drain well, you increase your safety factors by installing the even more easily draining materials above. Make sure the drainage system has a positive gravity drain to daylite

Hi Wes: Thanks for the info. I will follow the advice you've offered. One question: should I parge the Durisol first?

Lynelle

Lynelle,
I doubt that parging would be necessary. Many of the peel and stick products recommend using a liquid primer before installing the membrane. This would probably serve the same purpose as the parging. I would check with your Durisol supplier for their recommendations.

with faswall which is similiar we parge then use a waterbased spray waterproofer ( acme coatings) then a layer of dimple board drain tile and gravel.

Ask Durisol

I prefer to use drain board on my ICF projects simple because I have had problems with peel and stick products not adhering sufficiently. If you use peel and stick be sure to prime.

I have built with Durisol before and I believe that Wes's procedure is probably the best. I would extend the peel-n-stick over the top of the footing to the so that any water that happens to collect on the top of the footing doesn't collect against the wall. You could even build up the top of the footing near the wall, so that everything is sloped away from the wall. Dimple sheet is also cheap insurance to ensure an air gap and drainage plane.