How do you add a drain to a concrete patio?

Author: Dr. Verona Cremin  |  Last update: Monday, April 20, 2026

Dig out the trench about 6 inches deep along the line, using a slope gauge to slope it 1/4 inch per foot. Dig a dry well about two to four feet wide and three feet deep at the low end of the trench. Line the trench with landscape fabric and gravel. Then lay in 4-inch perforated drainpipe with the holes facing down.

Can you add a drain to existing concrete?

Yes, you can add a trench drain to existing concrete.

What if my patio has no drainage?

If the existing concrete patio lacks a drainage system, it is a practical move to install one. In areas where the rainwater collects, cut a sloping channel. A well-cut channel directs the water away from the patio. Fill the channel with decorative stones or gravel so it meets aesthetic ideals.

Can you add plumbing to an existing concrete slab?

The traditional way of installing plumbing would be to cut through your concrete slab so you can lay the plumbing and connect it to your existing sewer point. This will give you the most seamless result, and the end result will be similar to if you had laid it in the slab from the beginning.

How to get rid of standing water on a concrete patio?

Where the water tends to collect, cut out a sloping channel in the concrete to direct the water away, filling it with decorative stone or gravel. Instead of gravel, you can also have a trench or channel drain made of metal installed.

DIY Drainage - French Drains On A Budget!

How to add drainage to a concrete patio?

Dig out the trench about 6 inches deep along the line, using a slope gauge to slope it 1/4 inch per foot. Dig a dry well about two to four feet wide and three feet deep at the low end of the trench. Line the trench with landscape fabric and gravel. Then lay in 4-inch perforated drainpipe with the holes facing down.

How to fix a concrete porch that holds water?

Repitch With Bare Concrete

In this latter application, you will first need to scarify the concrete to the proper concrete surface profile (CSP) according to the application instructions of the waterproofing system chosen to repitch the deck. After scarifying, clean the area and blow with a blower.

How much does it cost to cut a concrete slab for plumbing?

Wall concrete sawing costs $15 to $35 per linear foot at 1” to 12” depths. Costs to cut a basement concrete floor for plumbing are $25 to $65 per linear foot at depths of 8” to 18”.

Can you run plumbing through concrete slab?

Plumbing can be run under concrete slabs of all kinds, including slab foundations. Plumbing is hidden by walls, floors, and roofs, but it also can run under concrete sidewalks, stoops, patios, and foundations.

Is it OK to pour concrete over existing concrete slab?

Concrete, no matter where you have it in your home, is durable and long lasting. However, when it does come time to replace your concrete - be it your driveway or backyard patio - there are a few steps to keep in mind. First, know that you can absolutely pour new concrete over existing concrete.

How to put a drain in a patio?

How to build a French drain for a patio:
  1. Dig a channel 500mm deep. ...
  2. Add a 50mm layer of bedding aggregate to the bottom of the channel.
  3. Cover the aggregate layer with landscaping fabric. ...
  4. With your channel prepped, you can add your drainage pipe, ensuring the fall remains the same and the perforated side is facing down.

What is the best drainage for a concrete patio?

A concrete patio drainage channel like Slot Drain is the ideal way to protect your outdoor recreation area from the damaging effects of water. The most efficient option available, Slot Drain is a sleek, easy-to-install option that will easily handle any water runoff from your patio area.

What is a soakaway?

A soakaway consists of a hole dug in the ground and filled with rubble or plastic crates. It provides a solution to excess surface water by letting it slowly drain and soak into the ground instead of build up.

Can PVC drain pipe be encased in concrete?

In summary, PVC pipes can be embedded in concrete, but they need to be handled with caution in practice. Its advantages are that it can protect pipes, save space and improve fire resistance, but it also has disadvantages such as installation difficulty, thermal expansion problems and difficulty in later maintenance.

How to pour a concrete drain?

7 Steps to Form the Perfect Concrete Trench Drain
  1. Determine the Width. After selecting the design and trench drain type, determine the correct width for the trench drain. ...
  2. Clear the Ditch and Install Rebar. ...
  3. Pour the Footer. ...
  4. Form the Inside. ...
  5. Top Frames. ...
  6. Outer Edge Forms. ...
  7. Pour the Drain.

Can pipes burst in concrete slab?

When a water pipe leaks or bursts under the concrete foundation, this is a slab leak. Often, a homeowner does not even realize water is leaking under and around the slab.

How deep are drain pipes under concrete slab?

Typically, a 12 to 24 inch depth of your plumbing pipes under a concrete slab house.

How do you install plumbing in an existing concrete slab?

There are two options for running the plumbing lines. For the nicest appearance, the concrete slab can be dug out and the drain and supply lines can be run through the trenches. Concrete is poured back in the trench to level the slab, and the new floor is covered with ceramic tile.

How long does plumbing last in a slab?

If your home is undergoing a renovation or remodel, you may want to consider repiping a house built on a slab during the construction project. It's easier to replace pipes inside walls before hanging drywall. Brass and copper pipes tend to last 80 to 100 years. Galvanized steel may only last 70 to 80 years.

How much does it cost to trench a concrete slab for plumbing?

The average cost to dig a trench is $950 per 100 linear feet, but prices can range from $400 to $1,200 depending on the purpose of your project, such as a drainage system or laying gas pipes. You should budget anywhere from $5 to $12 per linear foot to dig a trench or $13 to $40 per linear foot for major projects.

How to add drainage to a patio?

Line your trench with permeable geotextile fabric and lay 20-40mm of clean aggregate to a depth of 75mm in the bottom. The aggregate must be an even depth and follow the fall. Then lay a 100mm perforated plastic drainage pipe in the centre of the trench on top of the gravel bed.

What happens when water sits on a concrete slab?

Despite being an incredibly durable material, concrete can be susceptible to damage, especially water damage. Concrete is porous and can absorb water, which can lead to cracking. This can allow water to travel further into a foundation which can lead to structural damage.

Why is my concrete porch sinking?

Typically, a porch sinks when the ground beneath it is compromised. This can be due to environmental factors or construction errors. Common causes include: Soil Compression: Uneven soil settling, where some parts are compressed while others stay unchanged, leads to many porches sinking.

Previous article
Can you get sick cleaning up mouse poop?
Next article
What is a predator for pest?