French Drain Rock Calculator

FAQs

How do you calculate rock for French drain? To calculate the amount of rock needed for a French drain, you’ll need to determine the length, width, and depth of the drain, then multiply these dimensions to get the volume in cubic feet. Divide the volume by the cubic feet per ton of the rock to find out how many tons you’ll need.

How do I calculate how much drainage rock I need? Calculate the volume of the French drain in cubic feet (length x width x depth), then divide by the cubic feet per ton of drainage rock.

How deep should gravel be in a French drain? Typically, the gravel depth in a French drain ranges from 6 to 12 inches.

Is 20mm gravel OK for French drain? Yes, 20mm gravel can be suitable for a French drain.

How much does 1 tonne of drain rock cover? Around 80 to 100 square feet at a depth of 2 inches.

How much gravel should be on top of a French drain? A few inches of gravel on top of the French drain can help with drainage and prevent soil from clogging the drain.

What is the best rock for a French drain? 3/4-inch crushed stone or angular gravel is often recommended for French drains due to its excellent drainage properties.

How thick should drainage rock be? Around 6 to 12 inches is common for the thickness of drainage rock in a French drain.

How much will 10 tons of gravel cover? Roughly 800 to 1000 square feet at a depth of 2 inches.

Do you need rock in the bottom of French drain? Yes, placing a layer of drainage rock at the bottom of the French drain helps facilitate water movement.

Should you put rock under French drain? Yes, placing drainage rock under a French drain helps with water flow and prevents soil from clogging the drain pipe.

Is deeper better for French drain? Deeper French drains can handle more water volume, but the depth should be appropriate for your specific drainage needs.

Is 10mm or 20mm better for French drain? Either can work, but 20mm gravel might provide better drainage due to larger particle size.

Is bigger gravel better for drainage? Larger gravel sizes can provide better drainage due to increased void space between particles.

How far will 1 ton of gravel cover? Around 80 to 100 square feet at a depth of 2 inches.

What is the cheapest drainage rock? Prices can vary, but commonly available crushed stone or angular gravel tends to be more cost-effective.

How many square meters does 1 ton of gravel cover? Approximately 7 to 10 square meters at a depth of 5cm.

How deep should a 4 inch French drain be? Around 8 to 12 inches deep is typical for a 4-inch French drain.

Do you put soil on top of French drain? Yes, you can cover the French drain with soil and grass to maintain the aesthetics of your landscape.

Can you make a French drain with just gravel? While some soil separation is recommended, you can use gravel as the main component of a French drain.

Will a French drain work without gravel? Gravel helps with drainage and prevents clogging, so it’s beneficial to include it in a French drain.

Do you put gravel under French drain pipe? Yes, placing gravel under the pipe helps with water flow and drainage.

Do you need sand for a French drain? Sand is not necessary for a French drain; gravel is the primary material used.

Is 10mm gravel OK for drainage? 10mm gravel can work for drainage, but larger sizes might be more effective at preventing clogs.

Are bigger rocks better for drainage? Bigger rocks can provide better drainage due to increased void space.

How much does it cost to install a French drain in the UK? Costs can vary greatly depending on factors like length, depth, and location. Estimated costs could range from £30 to £60 per linear meter.

How much does 850kg of gravel cover? Approximately 60 to 85 square meters at a depth of 5cm.

How do you calculate rock coverage? Divide the area you want to cover (in square feet or square meters) by the area a ton of rock can cover at your desired depth.

How do I calculate how much gravel I need? Calculate the volume of the area you want to cover (length x width x depth), then divide by the volume a ton of gravel can cover.

Do you need fabric around French drain? Geotextile fabric can help prevent soil from entering the drain and clogging it, but it’s not always necessary.

Where not to put a French drain? Avoid placing French drains where they could direct water towards structures or create erosion issues.

Can you bury a French drain with dirt? You can cover a French drain with soil, but ensure there’s a layer of gravel to maintain drainage.

What do you put in the bottom of a French drain? A layer of drainage gravel at the bottom of a French drain helps with water movement.

Should a French drain go behind or in front of a retaining wall? A French drain should typically go behind a retaining wall to prevent water buildup.

Is pea gravel good for French drain? Pea gravel can work for a French drain, but its smaller size might lead to more clogs compared to larger crushed stone.

Can you have too much slope in a French drain? Excessive slope can lead to water moving too quickly and eroding the soil. A moderate slope is generally ideal.

How deep should a French drain be UK? In the UK, a French drain should be around 300mm to 450mm deep.

Is smooth or corrugated pipe better for French drain? Corrugated pipe with perforations is commonly used for French drains as it allows water to enter from all sides.

Should I use 3 inch or 4 inch pipe for French drain? Both 3-inch and 4-inch pipes can work for French drains, but larger pipes can handle more water flow.

How much slope does a French drain need? A slope of 1% (1/8 inch per foot) is often sufficient for proper water flow in a French drain.

Is sand or gravel better for French drains? Gravel is better for French drains as it provides good drainage and prevents clogs.

How deep should 10mm gravel be? Around 4 to 6 inches is suitable for 10mm gravel in a French drain.

How deep should 20mm gravel be? Around 6 to 8 inches is suitable for 20mm gravel in a French drain.

What is the best size gravel for drainage? 3/4-inch crushed stone or angular gravel is commonly considered the best size for drainage.

What is the best pipe for a French drain? Corrugated pipe with perforations is commonly used for French drains.

What is the best gravel for water runoff? Angular crushed stone or gravel with good drainage properties is best for water runoff.

What is the best gravel to stop water accumulation? Larger-sized gravel with good drainage properties is effective in preventing water accumulation.

How much is a ton of gravel cost UK? Costs vary, but as of my last update in 2021, prices could range from £40 to £60 per ton.

How much gravel will 2 ton cover? Around 160 to 200 square feet at a depth of 2 inches.

What area does a 1 ton bag of gravel cover? Approximately 80 to 100 square feet at a depth of 2 inches.

What do you put under drainage rocks? A geotextile fabric can be placed under drainage rocks to prevent soil from clogging the rocks.

How do I calculate how much drainage rock I need? Calculate the volume of the drainage area (length x width x depth), then divide by the volume a ton of drainage rock can cover.

How much does a tonne of gravel cost? Prices vary, but as of 2021, it could range from £20 to £50 per tonne.

How many m2 does a tonne cover? Around 7 to 10 square meters at a depth of 5cm.

How deep should my gravel be? Gravel depth depends on the purpose, but 2 to 4 inches is common for landscaping applications.

What is the best rock for a French drain? Crushed stone or angular gravel with good drainage properties is best for French drains.

How far to bury French drain? Aim to bury the French drain at least 12 to 18 inches deep for effective drainage.

What size rock do you use for French drain? 3/4-inch crushed stone or angular gravel is commonly used for French drains.

Should you put plastic under French drain? Plastic is not typically used under a French drain, as it can trap water and lead to issues.

Do you need rock in the bottom of French drain? Yes, placing a layer of drainage rock at the bottom of a French drain helps with water movement.

Should you put rock under French drain? Yes, placing drainage rock under a French drain helps with water flow and prevents soil from clogging the drain pipe.

Is 20mm gravel OK for French drain? Yes, 20mm gravel can be suitable for a French drain.

Why do you need a pipe in a French drain? The pipe in a French drain helps collect and channel water away from the area, preventing water accumulation.

How far from house should a French drain be? A French drain should be placed at a distance of at least 10 feet from the house foundation.

Should I use gravel or river rock for French drain? Both can work, but angular gravel is often preferred for better drainage.

Should you cover French drain with dirt? Yes, you can cover the French drain with soil and grass to maintain the aesthetics of your landscape.

How much gravel goes on top of French drain? A few inches of gravel on top of the French drain can help with drainage and prevent soil from clogging the drain.

Can you make a French drain with just gravel? While some soil separation is recommended, you can use gravel as the main component of a French drain.

Do you put gravel on top of French drain? Yes, a layer of gravel on top of the French drain can help with drainage and prevent clogs.

Should a French drain be covered with grass? Yes, you can cover a French drain with soil and grass for a more seamless appearance in your landscape.