ground slopes toward foundation

[mrsgator88]

Hi,

We constructed an addition on the side of our house. The construction is wood framing with exterior siding. The foundation wasn't poured high enough, and when the builder levelled the soil it was touching the bottom row of siding, and the yard was basically flat. The ground soil next to the addition was never tamped. The adjacent property slopes toward ours.

I was told by several people that you want several inches of exposed foundation between the soil and the siding. I rented a machine and cleared the soil away from the siding, and now I'm concerned about drawing more water towards the foundation. I'm wondering what the best course of action is. I've considered doing the following:

1) Build up the soil back to the point where the siding begins to have a more level yard, even though the soil will meet the siding.

2) Put in an earthen berm near the house, about 12-18 from the wall, and plant bushes. This would create a minor slope towards the house but also (hopefully) create a barrier against the water coming down from my neighbor's property. Maybe the bushes would soak up some extra water too.

3) Hire someone to remove a foot of siding, replace it with something strong and waterproof, and maybe put in a retaining wall for aesthetics.

The builder abandoned the job towards the end, so I'm kinda on my own for this. I'm in Illinois, north of Chicago. TIA for any help or opinions

[Dave]

If I understand the problem, you have adjacent neighboring property that has an incline towards your property. And, that incline is adjacent to the side of the house where the addition exists.

Many things have to happen. You need splash clearance from the soil so your siding is not damaged. There needs to be an incline from the house outwards to at least the dripline or 2 feet, whichever is greater. This is to keep standing water away from the foundation. The soil in the yard needs to route the water from the neighboring incline around the house. The depth and width must accomodate any amount of water coming from this incline and natural precipitation above it without standing water occurring. Dave

[Steve]

"mrsgator88" wrote on 03 Sep 2007 in group alt.building.construction:

Nope -- you need several inches of bare foundation to keep water from running under the sill plate and to discourage termites. The soil should never contact any portion of your house except the foundation.

Nope -- the ground needs to slope _away_ from the house.

Nope -- see 1).

4) Build a swale (a wide, shallow ditch) at least four feet away from the side of the house. The goal is to have the water flow away from the foundation, into the swale, and around the corners of the house to the street. You'll need to use a transit or a water level to ensure that the slope of the swale runs the water in the right direction. If a swale doesn't work, you'll need to install drains.

Water control is important for the health of your foundation and basement (if you have one).

[mogator88]

There is a problem with the swale. Our street has a raised curb and sidewalk, and from the sidewalk the ground slopes down to our house. In fact, where the driveway meets the garage the builder had to install a grates and a drain. So a swale would have to run to the rear of the property, and there's a shed in the way that's already sinking.

Installing drains would not be complicated. My town requires all downspouts to connect to the municipal storm sewer system. Yes, that's right. We actually have two sewer systems, one for waste, one for runoff. So, the pipes I'd need to connect to are already in place and fairly easy to get to, since there's a downspout at the low corner and a cleanout at the high corner.

My questions are now, what kind of drain do I want, and where should I place it? Thanks

[Steve]

mogator88 wrote on 04 Sep 2007 in group alt.building.construction:

I hate it when the house is lower than the street. Everything is more complicated. :)

Since you have such an accommodating town, I'd put in a French drain and attach it to the existing lines. In the strictest sense, a French drain is just a ditch filled with gravel. FDs are usually improved by putting a perforated pipe near the bottom to increase the flow. The pipe can be connected to your existing drain system. I'd also put a rain gutter on the roof and connect the downspouts to this system.

FDs are superior to simply connecting the downspouts to the existing system because the FD can collect water along its entire length, not just from the downspouts.

I'd put the FD several feet away from the foundation and make it low enough that the soil slopes away from the house. I like a grade of about 1/2" per foot, but your code or special conditions may be different. Around here (Arlington, TX), code requires that 6" of foundation be exposed.

[CWatters]

or perhaps linear dranage product...

We have a similar situation to the OP. The ground slopes towards the house because we built on a hill. We excavated a patio area into the hill and arranged for it to slope gently away from the house. We built a small retaining wall just high enough to sit on comfortably. We installed a linear drain at the foot of the wall. We also put a french drain on the uphill side..

House - patio - linear drain - wall - french drain - hill/lawn

[Dave]

Similar problem here was addressed by builder. They simply built the leading (low side) of the piers higher to accommodate the soil grading modifications later. The entire house (pier and beam) is a bit higher off the the ground due to this. After adding topsoil, and forming a downgrade from the house all around, the side of the house facing the hill (bottom of siding) is about 8" from the soil line. The general layout of how most of the rainwater is removed before hitting the edges of the soil downgrade adjacent to the house is outlined in my other reply. Simple grading.

I have a 10X10X8 french drain used for purged water from my aerator system for the well water. The area does get soggy when there's alot of rain (mushy). Otherwise, is firm to stepping in the area. Slightly uphill and canty-corner from the house, some 50 ft. away.

Am guessing the original contractor was building into the grade (hill) with the addition and attempting to maintain the slab level to the current home regarding to the original post. Just following the plans provided. Post construction soil grading is lastly done as far as the builder "abandoning" the job. Dave