French Drain Calculator
Plan your French drain project by calculating materials and requirements
French Drain Calculator
Table of Contents
How to Use the French Drain Calculator
Our French drain calculator helps you determine the materials needed for your drainage project. Follow these steps:
- Enter your drain length in inches
- Specify the drain width (standard is 18 inches)
- Input the drain depth (standard is 24 inches)
- Enter prices for gravel, pipe, and landscape fabric
The calculator will provide estimates for trench volume, materials needed, and total cost.
About French Drains
A French drain is a drainage system that includes:
- Gravel-filled trench for water collection
- Perforated pipe for water transport
- Landscape fabric to prevent soil infiltration
- Proper slope for water flow
- Connection to drainage outlet
- Optional surface grates or catch basins
French drains help prevent water damage by redirecting surface water and groundwater away from structures.
Materials and Tools
Essential materials and tools for French drain installation:
- Drainage gravel (3/4 inch or larger)
- Perforated pipe (4-inch diameter typical)
- Non-woven landscape fabric
- Shovel or trenching tool
- Level and string line
- Tape measure
- Wheelbarrow
- Safety equipment
Installation Tips
- Call utility companies before digging
- Ensure proper slope (minimum 1% grade)
- Install fabric before adding gravel
- Place pipe with holes facing down
- Use clean gravel without fines
- Overlap fabric edges properly
- Plan for proper water discharge
- Consider local building codes
Frequently Asked Questions
How deep should a French drain be?
Standard depth is 24 inches, but can vary based on your needs. The drain should be deep enough to intercept water flow and protect foundations, typically 2-3 feet deep.
What type of gravel is best?
Use clean, washed gravel that's 3/4 inch to 1-1/2 inches in size. Avoid rounded stones as they don't lock together as well as angular gravel.
Do I need a permit?
Check local regulations as permit requirements vary. Some areas require permits for drainage work, especially if it affects neighboring properties.