Advertisement | By XINENGXING
Originally published: 2026-05-28. Updated for the XINENGXING English website.
Proper drainage is essential for laundromat operation, managing the large volumes of water discharged by washing machines. Use model-specific discharge data and qualified plumbing design to address site conditions and local requirements.
Washing machines discharge significant water volumes during each cycle. Multiple machines operating simultaneously create substantial peak flow. Drainage systems must handle peak discharge volumes.
Drain sizing must accommodate peak flow. Undersized drains can cause backups and flooding. Calculating peak discharge determines drain capacity requirements.
Drainage velocity affects solid transport. Drains must maintain sufficient flow velocity to carry lint and debris. Low-velocity drains may experience accumulation and blockage.
PVC pipe is common for laundry drainage. Select pipe materials for the actual discharge temperature, chemistry and local rules; PVC is not suitable for every installation.
Cast iron pipe provides durability and noise reduction. Cast iron reduces the sound of flowing water. This material is more expensive but offers benefits in some applications.
Trench drains provide capacity for multiple machines. Open channel drains handle discharge from multiple machines. Trench drains require proper slope and cleaning access.
Drain slope affects flow velocity. Specify the required gradient and flow conditions under the applicable design rules. Have the designer determine pipe size and gradient together rather than using a universal slope rule.
Drain size affects capacity. Larger diameter pipes carry more flow. Size the system for peak discharge to reduce backup risk.
Cleanouts enable maintenance access. Drains should include cleanouts for clearing blockages. Cleanout spacing enables access throughout the drain system.
Lint traps capture debris before it enters drains. Machine filtration varies; check what the selected equipment retains and what reaches the drain. Additional filtration may be needed for some installations.
Grease interceptors may be required by code. Confirm with the local wastewater authority whether lint interception, grease separation or other treatment is required for the actual discharge.
Regular cleaning prevents accumulation. Lint and debris accumulate in drains over time. Scheduled cleaning maintains drainage capacity.
Backflow prevention protects water supplies. Devices prevent contaminated water from flowing back into supply lines. Code requirements specify backflow prevention devices.
Floor drain traps prevent sewer gas entry. Water seals in drain traps block sewer gas. Check trap seals and any required trap-priming arrangement.
Where appropriate, a designer may specify a suitable backwater valve to reduce sewer-backup risk. Selection, access and maintenance are important; a valve does not prevent every cause of flooding.
Sump pumps may be necessary for below-grade drainage. Pumps lift water to higher elevation drains. Size pumps for required flow, head and service conditions.
Dual pumps provide redundancy. Facilities relying on sump pumps should have backup systems. A backup arrangement can reduce disruption, but power supply, pump controls and overflow risks also need consideration.
Alarms indicate high water levels. Float switches trigger alarms when sump levels rise. Early warning enables response before flooding occurs.
Floor drains capture spills and overflow. Laundry facilities should have adequate floor drains. Floor slope directs water to drains.
Floor drain maintenance prevents odors. Drains that receive little flow may dry out, allowing sewer gas entry. Regular water addition maintains trap seals.
Floor construction affects drainage. Floors should slope to drains with no low spots where water accumulates. Proper floor construction enables effective drainage.
Greywater systems capture and reuse discharge water. Treatment systems enable water recycling. Water reclamation reduces consumption and costs.
Filtration removes contaminants. Sand filters, membrane systems, or other technologies treat discharge water. Reuse requires treatment, monitoring and permitted end uses appropriate to the water quality and local rules.
Economic analysis determines viability. Water costs, treatment costs, and system life affect return on investment. Assess installation, operation, testing, maintenance and replacement costs under realistic demand scenarios.
Plumbing codes specify drainage requirements. Local codes may have specific requirements for laundry facilities. Compliance is mandatory.
Permits and inspections verify compliance. Drainage installation typically requires permits. Arrange the permits and inspections required by the responsible authority.
Environmental regulations may apply. Some jurisdictions have regulations on laundry discharge. Confirm discharge requirements before installation and keep the required records.
Regular inspection identifies developing problems. Visual inspection of drains and cleanouts catches issues early. Inspection during maintenance helps identify developing faults.
Cleaning schedules maintain capacity. Frequency depends on usage volume and lint generation. Regular cleaning helps control blockage risk.
Documentation tracks maintenance history. Records of cleaning, repairs, and inspections support management. Historical data enables informed maintenance planning.