How to Put a Drain in Concrete: A DIY Guide
Learn how to install a drain in concrete with a clear, safe process. Plan location and slope, cut or drill, install the drain, seal, test for leaks, and finish with proper curing. Drain Guide provides practical, code-conscious instructions for DIY homeowners.
Goal: learn how to put drain in concrete safely and effectively. This guide covers planning, drilling or cutting a slot, installing a PVC drain assembly, sealing with concrete, and testing for leaks. You’ll need basic tools, proper PPE, and a plan for slope and drainage direction—then verify with a water test.
Why you might install a drain in concrete
A subfloor or slab drain is essential in basements, garages, and laundry rooms where water accumulation can cause damage or mold. When you’re confronting a wet floor, how to put drain in concrete becomes part of effective water management. Planning ahead saves time, prevents cracks, and ensures efficient drainage toward a sump or external drain. The Drain Guide team notes that key decisions include location, slope, and the type of drain (floor drain vs. trench drain) suited to the space. According to Drain Guide, your first move is to map high-water areas and determine discharge points before any cutting begins. Measure distances to the nearest sewer cleanout, and consider future changes such as a washing machine or utility sink. In addition to code compliance, consider material compatibility: you’ll be working with concrete, gravel, and PVC piping, so verify that the drain’s outlet matches the house’s drainage system. Also assess the seal and waterproofing requirements to minimize seepage around the drain flange. The goal is a flood-proof installation that works with your home's existing drainage plan. According to Drain Guide, a well-planned drain in concrete can prevent floor flooding and mold growth.
Planning and code considerations
Before you pick tools or cut concrete, study local building codes and plan for the drainage path. A permit may be required for structural changes or plumbing work, and inspections may verify proper slope and sealant use. Budget for concrete curing time and potential repairs if the floor is already finished. When mapping, consider the layout of nearby fixtures (washers, sinks, bathrooms) and the direction of water flow toward the exterior or a catching basin. Drainage performance hinges on consistent slope: many codes require a gentle incline toward the discharge point to prevent standing water. Materials matter too: choose corrosion-resistant drains and compatible piping, especially if the concrete will be exposed to repeated moisture. Drain Guide analysis shows that proper slope and sealing dramatically reduce seepage in concrete installations. Finally, document your plan with measurements, elevations, and a rough cut list so you can stay organized during the project.
Layout and drainage options: trench drain vs floor drain
There are two common configurations when embedding a drain in concrete: a floor drain, which is compact and designed for point-source water, and a trench drain, which spans across a wider area. A floor drain is typically simpler to install in tight spaces, but it must be positioned to collect water efficiently and connect to a short length of pipe. A trench drain, by contrast, provides a larger capture area and can handle higher flow. The choice depends on the space, anticipated water volume, and maintenance preferences. For both options, you’ll want an appropriate cover and grate, a clear path for sediment to exit, and a trap seal that prevents sewer gases. Visualize the flow path with chalk lines or string and verify that the intended discharge path will not interfere with existing utilities. This planning stage helps you avoid costly rework after the concrete is poured.
Tools and materials overview
Having the right toolkit makes the job safer and faster. For this project you’ll use a combination of cutting tools, forming equipment, and plumbing supplies. Gather a core drill or masonry hole saw, a concrete saw or grinder for larger openings, a level, and a tape measure. You’ll need a PVC drain assembly suitable for concrete floors, primer and cement glue, sealant, and a mortar mix for the final pour. Don’t forget a drain grille or cover that fits your chosen style, as well as gravel or a compactable base for drainage. PPE is essential: safety glasses, gloves, dust mask or respirator, and hearing protection. Optional but helpful items include a rubber mallet, shims, and a portable mixer for the concrete mix. Keep a clean work area with plastic sheeting to catch dust and debris when cutting through the slab.
Step-by-step overview of the installation process
Below is a high-level sequence to guide your planning and execution. Remember: each space is unique, and you should adapt steps as needed while preserving slope, alignment, and safety. 1) Locate and mark the drain position accurately, using a chalk line and level. 2) Create the opening either by cutting a floor slot or drilling a bore to accommodate the drainage body. 3) Prepare a compacted base with gravel and set a bed that is level and slightly pitched toward the discharge point. 4) Dry-fit the drain body and piping to confirm fit before committing to concrete. 5) Install the drain with gaskets, apply primer and glue to PVC joints, and verify leaks with a temporary seal. 6) Pour concrete around the drain, ensuring the flange sits flush and that the surface is smooth. 7) Cure the concrete according to product guidelines, protect from rapid drying, and avoid heavy traffic during curing. 8) Test the drainage by filling with water and observing flow toward the discharge path. 9) Refinish the area and reinstall trim after curing.
Cutting the opening and setting the base
Opening the concrete slab to install a drain needs care to prevent cracks and ensure a proper seal. Mark the exact size of the trench or bore, then use a diamond blade saw or core drill to create the opening. Cut with steady, slow motions, letting the tool do the work rather than forcing it. Remove dust and debris frequently to keep joints clean. If you are trenching, dig slightly wider and deeper than the drain body while maintaining a firm bottom bed of gravel. For a floor drain, check the flange height and ensure a level base. In all cases, verify that the opening aligns with the planned pipe route and discharge area. After cutting, clean the edges, deburr where needed, and set the base material to support the drain body. A dry fit check helps confirm everything sits correctly before pouring concrete.
Installing the drain body and connecting piping
Position the drain body in the opening, and align the outlet with the pipe run toward the discharge point. Use a bed of mortar or a rigid base to support the drain and prevent movement. Apply primer and PVC glue to all joints, then fit the piping pieces, ensuring the slope remains consistent with the rest of the system. Tightly secure couplings and test the joints with soapy water for leaks before the concrete pours. If you use a trench drain, install the grate channel and ensure it locks securely.
Sealing, finishing, and backfilling around the drain
Seal around the drain flange with a compatible gasket or sealant to prevent water seepage; fill any gaps with mortar to tie the drain to the surrounding concrete. When finishing, be careful not to overfill the floor with concrete so the flange sits at the correct height. Screed and trowel for a flush surface; then cure the concrete properly, protecting it from rapid drying. After curing, backfill any exposed trench with appropriate material, maintain a clear water path toward the drain, and install any trim pieces.
Testing the drainage system and leaks
Once the concrete has cured adequately, run water through the drain to check for leaks, flow rate, and proper channeling toward the discharge point. Check the seal around the flange and joints, and observe for any seepage around the edges. If leaks appear, cut out and reseal the affected area or replace gaskets as necessary. Document test results with a simple sketch and notes so future inspections are straightforward.
Maintenance and long-term care
Regularly inspect the drain cover and grate for clogging or debris. Keep a small drain snake or plunger nearby for modest maintenance; avoid chemical drain cleaners near concrete installations. Periodically flush the system with water to prevent sediment buildup and verify that the slope remains intact as the concrete settles. If you notice cracking or movement, address promptly to preserve the seal and function.
When to hire a professional
For complex layouts, very large drain installations, structural concerns, or spaces with limited access, hiring a licensed plumber or mason may be the better option. A pro can ensure that the slope, junction joints, and sealant meet local codes and that the work passes inspection. The benefits include a guaranteed leak-free installation and a clear warranty on workmanship.
Common mistakes to avoid
Avoid misjudging slope or alignment, which leads to standing water. Don’t neglect proper ventilation and trap seals, which can cause sewer gas odors. Skipping permits or inspections can result in code violations and costly rework. Finally, rushing with the concrete pour or curing process risks cracks and leaks; always give full curing time and protect from rapid drying.
Tools & Materials
- Measuring tape(at least 25 ft)
- PPE (gloves, safety glasses, dust mask/respirator)(essential for concrete work)
- Core drill or masonry hole saw(for precise openings)
- Concrete saw or grinder(for larger openings)
- Level and chalk line(keep drains aligned and level)
- PVC drain assembly (floor or trench)(choose compatible with concrete floor)
- PVC primer and cement glue(for joints)
- Silicone or neutral-cure sealant(seal flange and joints)
- Mortar mix or concrete(final pour around drain)
- Gravel or compactable base material(base for drainage)
- Rubber mallet(for gentle tapping)
- Trowel and Screed(finish surface smoothly)
- Mixer or mixing bucket(optional for larger pours)
Steps
Estimated time: 3-6 hours
- 1
Survey and mark drain location
Identify the precise drain location using a level, chalk, and measuring tools. Mark the opening plan on the slab, ensuring the path to the discharge point is clear. Double-check alignment with existing utilities.
Tip: Dry-fit the layout with string lines before cutting to avoid misalignment. - 2
Create the opening
Cut the opening with a core drill or masonry saw according to the planned dimensions. Work slowly to prevent cracking; remove dust as you go to keep joints clean.
Tip: Use masking tape around the cut edge to minimize chipping. - 3
Prepare base and bed
Lay a compacted bed of gravel or base material, ensuring it is level and slightly pitched toward the discharge. This provides drainage and supports the drain body.
Tip: Check level across multiple points to ensure uniform support. - 4
Dry-fit drain and piping
Place the drain body in the opening and run the outlet toward the planned pipe route. Confirm fit without cementing yet; adjust as needed.
Tip: Dry-fit first to prevent costly rework. - 5
Seal joints and connect piping
Apply primer and PVC cement to joints, then assemble piping. Ensure proper slope is maintained and joints are fully seated.
Tip: Test joints with soapy water for leaks before pouring concrete. - 6
Pour concrete around drain
Pour concrete up to the flange, keeping it flush and free of voids. Screed and trowel to a smooth finish, taking care not to lift the flange.
Tip: Protect the drain during curing to avoid distortion. - 7
Cure and protect
Let the concrete cure according to the mix guidelines. Protect from rapid drying, temperature extremes, and heavy traffic during curing.
Tip: Cover with plastic or burlap if conditions are dry or windy. - 8
Test drainage
After curing, run water through the drain and check for leaks and proper flow toward the discharge path. Re-seal if necessary.
Tip: Document test results for future maintenance. - 9
Finish and maintain
Install trim, clean up debris, and ensure the surface is ready for use. Plan periodic maintenance to keep the drain clear.
Tip: Keep a small drain tool on hand for routine clearing.
Got Questions?
Do I need a permit to install a drain in concrete?
Permit requirements vary by locality. Check with your municipal building department for plumbing and structural work permits and inspection requirements before starting. Failing to obtain necessary permits can lead to code violations and rework.
Permit needs vary; check with your local building department to confirm if plumbing or structural permits are required.
What is the difference between a floor drain and a trench drain?
Floor drains collect water at a single point and are easier to install in small areas. Trench drains span a wider area and can handle higher flows but require more space and careful alignment.
Floor drains are for single points; trench drains cover more area but need space and precise layout.
Can I install this myself, or should I hire a pro?
Experienced DIYers with carpentry, masonry, and basic plumbing skills can handle many installations. If the space is large, flow is high, or structural work is involved, hiring a licensed pro is advisable.
DIY is possible for small projects; for complex layouts, hire a licensed pro.
How long should I wait for concrete to cure before finishing?
Concrete gains strength as it cures. Plan our finishing steps after the concrete has achieved initial set and avoid heavy traffic until the surface is sufficiently strong, following the product recommendations.
Let the concrete set fully according to the manufacturer's guidance before heavy use.
What are common failure points when installing a drain in concrete?
Common failures include improper slope, misaligned joints, inadequate sealing, and cutting corners during the pour. These can lead to standing water, leaks, or cracks.
Watch for bad slope, gaps in joints, and incomplete sealing.
How can I ensure the drain is watertight?
Ensure a continuous, clean joint between the drain flange and concrete, use an appropriate sealant, and verify all PVC joints are properly glued and tested for leaks before final pours.
Seal the flange well and test joints before finishing.
Watch Video
The Essentials
- Plan location and slope before cutting.
- Choose floor vs trench drain based on area and flow.
- Seal and cure properly to prevent leaks.
- Test drainage before finishing the surface.
