wood soil contact problem

[gobby]

hi,
I bought an 80 year old semi in Toronto a couple of months ago and I am going through the process of bringing it up to par after years as a rental unit. I have a problem at the rear of the house with grading. The lot is sloping up from front to back, with a paved shared drive running up the side of the house (north facing). The top of the foundation at the rear of the house appears to be sitting approx. 8-12" below grade right now. The house is wood frame, with insulbrick siding that I am removing to replace with vinyl (or something better if I can afford it). The walk out into the back from the kitchen is only 3" above grade right now and I want to correct the wood soil contact problem at this wall. My problem is that I can not see how I can remedy this problem though grading alone because I would need to go down 16" in order to get the soil a safe distance from the sill plate, which would create a very steep negative grade towards the foundation from the rest of the yard( the slope of the back is probably 1 in 15 towards the house).
Is there any way I can excavate a trench at the back of the house and add a material to the top of the foundation/bottom of wall to effectively protect the sill plate and the base of the wall from moisture and bugs, and then grade properly from 5" below the top of this material? I think that the yard could drain properly if I could do this.
Any suggestions would be greatly appreciated.

[doyle]

I'm picturing a house a friend of mine has that fits your description perfectly. Same alyout of the land, same problems at the back of the house. He fixed the problem by digging a trench, or trough if you will, along the back of the house. A 16" tall retaining wall holds back the earth, and there is concrete at the bottom as well. Just picture a 16" square concrete 3-sided ditch along the back of the house, which would perhaps turn at the corner of the house so the water would flow toward the street (or driveway if you wish). The access to the rear door is handled by building a wood footbridge with handrails, or even building a concrete bridge.

This may not be an easy or cheap method of doing what you need, but it's certainly effective.

[mjpliv]

What Doyle say's is the prefered way to handle your problem. Its kind of like an extended window well. Although, if you have decent footing drainage, just use a stone base inside, or even use top soil and plant it.

Just for reference, National Building Code of Canada (1995) states that the minimum clearence between finished grade and any non-masonary wall surface is 8"

[gobby]

Thanks for the idea. Would you need to provide drainage at the bottom of the well or is sloping the bottom towards the driveway sufficient? Does anyone know of a source for details on a retaining wall of this sort? The house had a step footing put in to lower the basement in 88 and I would hope that they would have delt with drainage properly then, but I think they try to do a lot of that work from the inside so there's no telling. Since I am unsure about the quality of drainage at the footing I think running the water out to the driveway is the best bet, but I also wonder if there are potentially any problems with shedding water onto a shared drive.

[mjpliv]

Do you have access to any rain water leaders? If your rain gutters feed into these and one is nearby you may be able to use a"hard" well (ie- concrete trough) with a sloped floor and a screened drain feeding into the rain water leaders just below grade. Its kind of like turning the trough into one jiant rain gutter. This would be a very inexpensive solution.

[mjpliv]

and the only way to be sure about your footing drains is to dig down and check. One of those mini-excavators that you can rent will do the trick.

[mjpliv]

If you go with the retaining wall you can cast it in concrete, use wolmanized landscaping logs or use a stacking, mortarless retaining wall system like Allen Blocks.

[gobby]

The trough feeds into the ground at the front of the house, so I would need to bury a drain along the side of the house to get there. I was honestly thinking surface runoff as the driveway is sloped away from the two houses properly. Didn't the building code just make an amendment saying that you can no longer drain from the footing or gutters into the house waste line?
Thanks for the advice, I'll keep updating this as I get more info.

[mjpliv]

You cannot feed them into the sewer system but they can be fed into the storm drains in most municipalities