Quick Verdict
To slope the ground away from your house in Oregon, the crew reshapes the soil around the foundation so water runs away from the wall instead of pooling against it. The dig combines machine work in the open yard with careful hand-grading tight to the foundation where a machine can't reach. Throughout, you protect the foundation drain and downspout lines and keep the new soil low enough that it never bridges the siding or weep screed. In wet Willamette Valley clay, getting this right is the difference between a dry crawlspace and a chronic water problem. Below is how the earthwork actually happens.
What Perimeter Grading Does
Water that ponds against a foundation finds its way in, through cracks, the cold joint, or simply by saturating the soil that wicks moisture to the wall. Sloping the grade away from the house is the first and cheapest line of defense. The goal is positive drainage: a consistent fall away from the foundation for the first several feet, so surface water and roof runoff head away from the building. This is execution-focused earthwork. For how the whole drainage system is designed, see the grading and drainage earthwork guide.
The Perimeter Dig, Step by Step
A regrade around a foundation follows a clear sequence:
- Assess the existing grade and find where water currently sits or runs toward the house.
- Locate and protect the foundation drain, downspout lines, and any utilities near the wall (call 811 first).
- Machine-grade the open yard, cutting high spots and shaping a consistent fall away from the foundation.
- Hand-grade tight to the wall where the machine can't safely reach, feathering soil to the right elevation against the foundation.
- Check the fall with a level or grade tool to confirm positive drainage all the way around.
- Stabilize the surface so the new grade holds, often with seed, mulch, or rock depending on use.
Hand-Grading Where the Machine Can't Reach
A machine is great in the open yard but can't work safely right against the house without risking the siding, the foundation, or buried lines. So the last band of soil next to the wall is graded by hand. This is slower and more skilled work: the laborer feathers the soil to a smooth, consistent slope away from the foundation, ties it into the machine-graded yard, and keeps it clean around drains and penetrations. Tight Willamette Valley lots, where the side yard between house and fence is narrow, lean even harder on hand-work because there's no room for the machine.
Protecting Drains and Downspout Lines
Reshaping soil around a foundation means working right where the foundation drain and downspout drain lines live. These have to be protected, not buried wrong or crushed:
- Foundation (footing) drain -- keep it functional and at the right depth; don't bury the daylight outlet or cleanouts.
- Downspout lines -- the buried pipes carrying roof water away must stay intact and keep their fall.
- Cleanouts and outlets -- keep them accessible and flowing.
If you regrade over these without care, you can defeat the very drainage system you're trying to help.
Keep Fill Below Siding and Weep Screed
This is a rule you don't break: the new soil has to stay below the bottom of the siding and below the weep screed on stucco. Pile soil up against the siding and you trap moisture against the wall, invite rot and pests, and void the screed's job of letting the wall drain. There's a required gap between finished grade and the siding, and the regrade has to respect it. It's tempting to keep adding soil to chase a slope, but the answer is often to cut elsewhere rather than pile fill against the wall.
Oregon Conditions That Make This Matter
- Saturated clay perimeters wick water to the slab and crawlspace, so a good slope away from the wall is critical in the valley.
- Freeze-thaw east of the Cascades can heave regraded soil over winter, so compaction and the right material matter.
- The wet-season window means the best time to regrade clay is the drier months, when soil is workable and the new grade can establish.
For the target numbers, the 6-inches-in-10-feet grading rule explains the slope to aim for, and regrade a yard for positive drainage covers the broader yard.
Common Regrading Mistakes That Make Drainage Worse
A bad regrade can leave a house wetter than before. These are the errors that cause it:
- Piling soil against the siding. The single most common mistake. It traps moisture on the wall, rots the bottom of the siding, and covers the weep screed. The fix is almost always to cut soil away somewhere, not add it at the wall.
- A slope that quits too soon. The fall has to carry water past the foundation. If the ground dips back down right past the slope, water still collects against the house.
- Burying the foundation drain's daylight outlet. Cover the spot where the footing drain exits to daylight and the whole drain backs up. The outlet and cleanouts have to stay open.
- Regrading saturated clay. Worked wet, Willamette Valley clay smears, won't compact, and slumps as it dries, so the careful new grade disappears over the first winter.
- No surface stabilization. Bare graded soil washes in the first hard Oregon rain. Seed, mulch, or rock holds the new grade until it sets.
How Much Slope and How Far Out
The target most crews build to is about 6 inches of drop over the first 10 feet away from the wall, roughly a 5 percent slope. That first 10-foot band matters most, because it's what carries water clear of the foundation. Past that, the ground can flatten out, as long as it never slopes back toward the house. On a tight lot without a full 10 feet before a fence or property line, the crew builds the steepest practical fall in the room available and may add a swale or a drain to carry water the rest of the way. The point isn't one exact number; it's a continuous, positive fall that never lets water sit against the wall.
What Perimeter Regrading Costs
Cost is driven by the linear feet of foundation perimeter, how much soil has to move, and how tight the access is. An open yard with room for a machine is cheaper per foot than a narrow side yard that forces hand-work.
| Cost Driver | Effect on Price |
|---|---|
| Perimeter length | More linear feet = more grading |
| Access | Tight side yards force slower hand-grading |
| Soil volume | More cut and fill = more time and haul |
| Drain protection | Working around existing lines adds care and time |
Current Market Reality
Costs run higher when access is tight, when a lot of hand-grading is required around drains and tight side yards, or when soil has to be hauled in or out to hit the right elevations without burying the siding.
The Bottom Line
Sloping the grade away from your house is a mix of machine grading in the yard and careful hand-grading at the wall, all while protecting the drains and keeping soil below the siding. Done right, it's one of the cheapest things you can do to keep water out of an Oregon home. For the full system, see the Oregon excavation contractor guide. Cojo grades and regrades around foundations across Oregon as part of our excavation services -- request a free estimate.