Regrading a lawn involves carefully reshaping the land to establish a proper slope. This process directs rainwater away from structures, protecting the home’s foundation from hydrostatic pressure and water damage. Without a correct grade, water can pool, leading to saturated soil and an unhealthy lawn. Adjusting the slope prevents costly basement flooding, foundation cracks, and landscape erosion. This article will guide you through the process of correctly regrading your lawn for effective drainage.
Identifying Drainage Problems and Slope Issues
Recognizing the signs of poor drainage is essential. Common indicators include standing water that lingers for more than 24 hours after rainfall, suggesting the ground is too flat or has low spots. Water flowing directly toward the house foundation or remaining muddy for days indicates the existing slope is insufficient. This constant moisture can lead to soil erosion, washing away loose topsoil and exposing tree roots.
A negative grade, where the land slopes toward the building, directs water against the foundation walls. This increases the risk of structural damage by causing the soil beneath the foundation to swell and contract, leading to settling, shifting, and cracking.
Essential Planning and Preparation
Accurate planning and calculation of the new grade are essential for a successful regrading project. The goal is to establish a positive slope that guides water away from the structure. For residential properties, a minimum 2% grade is standard, translating to a fall of about 6 inches for every 10 horizontal feet extending from the foundation. This incline ensures runoff while preventing rapid erosion.
To determine the required change, measure the existing slope using stakes, a string line, and a line level. If the ground 10 feet from the house is less than 6 inches lower than the foundation, you must add soil. Calculate the volume of soil needed by determining the area to be regraded and multiplying it by the desired height change.
Before starting, contact local utility companies to have existing underground lines marked. For the material, use clean fill dirt for the bulk of the grade change, followed by a layer of screened topsoil for the final surface. Purchasing soil by the cubic yard is generally more cost-effective for larger areas. Finally, check with your municipality for any necessary permits or local regulations regarding changing the grade of your property.
Necessary Tools
- A sod cutter for removing existing turf.
- Shovels and a wheelbarrow for moving material.
- A sturdy landscape rake for spreading the soil evenly.
- A string line and level for measuring the grade.
Executing the Grading Process
The physical work begins by removing the existing lawn in the designated areas. A rented sod cutter or a sharp spade can be used to slice the turf, exposing the bare earth for reshaping.
Next, establish the new grade using the planning measurements. Drive stakes into the ground along the planned contour and pull string lines taut between them, setting them at the precise height of the intended finished grade. These lines act as a visual guide to ensure a consistent slope.
Start moving soil by scraping down high spots and using that material to fill nearby low spots. If the grade needs significant raising, spread new fill dirt across the area, starting nearest the foundation and working outward to maintain the positive slope. Use a wide grading rake or the back of a shovel to rough-grade the soil, checking the surface against the string lines.
The soil should then be compacted lightly to prevent excessive settling that could ruin the new grade. Use a water-filled lawn roller or a hand tamper to achieve this, making sure to compact in layers if adding more than a few inches of material. Compaction should leave the soil firm but not overly dense, which would inhibit future root growth. Finally, use the string line and level to confirm the new surface accurately reflects the planned slope.
Finalizing the Surface and Long-Term Care
Once the grade is established, prepare the surface for the new lawn. Apply a layer of high-quality topsoil, typically 4 to 6 inches deep, over the new grade to provide a nutrient-rich environment. Rake the topsoil smooth to ensure an even surface for optimal seed-to-soil contact or sod placement.
You have two options for the final surface:
Seeding and Sod Installation
If seeding, use a starter fertilizer and cover the seed with a thin layer of peat moss to retain moisture. If laying sod, roll the strips tightly against each other, staggering the seams, and use a roller to press the sod firmly against the prepared soil.
The initial watering routine is crucial for success. The top inch of soil must be kept consistently moist to encourage germination and root establishment. New seed requires light watering multiple times a day for the first few weeks, gradually decreasing frequency as the grass matures. New sod requires deep, consistent watering for the first two weeks. Monitor the area during the first heavy rainfalls to confirm water is flowing away as intended, making minor adjustments if any pooling is observed.