An outdoor shower can be a great addition to a home, allowing you to rinse off after using the pool or jacuzzi, or just enjoy an open air shower experience. However, proper drainage is essential for an outdoor shower to function well and prevent water buildup and damage. There are a few main types of drainage systems used for outdoor showers.
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Types of Drainage Systems for Outdoor Showers
Gravity Drainage
Gravity drainage relies on a sloped floor or floor drain to remove water. This is the most basic and affordable drainage option. The shower floor itself can be sloped to direct water to a drain located at the lowest point. A typical slope is 1/4 inch vertical drop per 1 foot horizontal run. The drain is then connected to the main sewer/septic line or a drywell. Having sufficient slope and proper floor materials like tile, stone, or concrete are key for effective gravity drainage.
Trench Drain
A trench drain is a long, narrow drain system installed just below the shower floor. Linear trench drains run parallel to walls to capture water. Multiple trenches can also be used, meeting in the middle or corner of the shower in a hub configuration. Trench drains are covered with grates and collect water quickly, requiring less slope than a standard gravity system. Stainless steel, plastic, and concrete are common trench drain materials.
Zero-Entry Shower
A zero-entry or walk-in shower does not have a raised threshold, allowing you to step or roll directly in without going over a curb. The entire shower area is sloped minimally to drain water toward discreet drains placed throughout the floor. Linear trench drains are often used with this open shower design. The look is contemporary, with tile extending past the shower area.
Choosing the Right Drainage System
Several factors should be taken into account when selecting an outdoor shower drainage system:
Type of Shower Foundation/Flooring
The foundation and flooring of the shower area impacts drainage options. A custom tiled shower floor with a concrete foundation allows you to create the ideal slope and place drains where needed. A shower installed on a raised wood platform may be limited to certain drain types and locations.
Space and Layout
The size and layout of the shower should be considered. Large or irregularly shaped showers may require multiple drains for sufficient drainage. The location of plumbing and sewer connections may also influence placement.
Shower Enclosure Type
Fully-enclosed showers with water barriers on all sides allow you to contain water and direct it to drains within the enclosure. Partially open showers need drainage systems that quickly draw water away so it doesn’t run into surrounding areas.
Climate Factors
In climates where freezing temperatures occur, drainage should be designed to prevent water sitting in pipes and drains and freezing. Drains need to be located for access to blow out lines before winter.
Local Building Codes
Most areas have plumbing codes for proper drainage and construction requirements. Be sure to check local building codes when planning outdoor shower drainage.
Budget
Simple gravity drainage is the most economical option. More complex systems with multiple drains, zero-entry style showers, and trench drains cost more to install.
Outdoor Shower Drainage Options
There are several types of drains that can be used with the various shower drainage systems:
Floor Drains
| Type | Description |
|---|---|
| Round floor drain | Low profile round drain with removable strainer |
| Square floor drain | Larger square drain with grates |
| Scupper drain | Floor drain with horizontal outlet for decks |
Floor drains have a flat rim that sits flush with the floor. They can be used with gravity drainage and zero-entry showers. Round drains are the most discreet option. Square drains handle more volume. Scupper drains work well on elevated wood or composite decks.
Trench Drains
| Type | Description |
|---|---|
| Cable trench drain | Linear drain made from thin metal channels |
| Modular trench drain | Interlocking plastic or concrete channel sections |
| Metal & fiberglass trench drains | One-piece prefabricated units |
Trench drains come in long sections that can be cut to fit. Cable style trenches have thin 1-2 inch channels. Modular and prefab trenches are larger 4-6 inch units. Durability, drainage capacity, and cost increase with trench size.
Alternative Drain Options
PVC pipe with perforations can be installed just under the shower floor to catch water. For a wood deck shower, spacing deck boards allows water to drain between them to the ground. Pea gravel or crushed stone under the floor can hold some drainage.
Outdoor Shower Drain Materials
Drain bodies and grates come in several material options:
Plastic
Plastic drains are lightweight and inexpensive but not very durable. They can become brittle and crack over time.
Concrete
Concrete trench drains are very sturdy but heavy and prone to cracking. Good for custom drainage channels.
Metal
Stainless steel, galvanized steel, and cast iron drains resist corrosion and stand up to outdoor use. Metal grates allow debris to fall through.
Composite
Drains made from molded plastics/resins mix durability and lighter weight. Composites typically have slotted grates.
Sizing the Drain and Plumbing
Proper sizing of drains and pipes is crucial for adequate water removal. Things to consider:
– Shower dimensions – Larger showers need more drainage capacity
– Flow rate of shower head – High capacity rain shower heads produce more water to drain
– Number of drains – More drains spread over the space provide more drainage points
– Drain grate size – Larger grate sizes over trenches and drains collect more water
– Outlet pipe size – Minimum 2-inch outlet pipes recommended, 4 inches for trenches
Consult a qualified plumber to ensure you have adequately sized drains and plumbing. Undersized drainage will cause water to back up and flood the shower.
Connecting to Plumbing
The outdoor shower drainage system must tie into the main plumbing of the home in some way to carry water away:
– **Sanitary sewer** – Connecting to an existing sewer line is the most direct option. A backwater valve is recommended to prevent sewage backups.
– **Septic system** – Drains can tie into septic tanks, but may require a sewage ejector pump if gravity flow is not possible. Septic safe soaps are a must.
– **Drywell** – A gravel filled pit that allows water to leach into the surrounding soil. Only options for low use showers due to limited capacity.
– **Storm drainage** – In some cases, shower water may be able to drain to a home’s storm water system, entering street storm drains. Check local codes.
– **Landscape drainage** – Draining water into a gravel trench that releases into landscaped areas or bioswales is an eco-friendly option.
Professional help is advised to properly design and tie outdoor shower drainage into existing home plumbing and drainage.
Maintenance
Like any drainage system, outdoor shower drains need regular inspection and maintenance:
– Remove debris from drain grates and strainers. Clogged drains lead to standing water.
– Flush pipes and trenches periodically to keep water flowing freely.
– Make sure outlet pipes remain securely connected. Fix leaks immediately.
– Check slope and drainage channels for settling and erosion that reduce drainage. Repair as needed.
– In freezing climates, disconnect hoses and drain pipes before winter.
– Lubricate and exercize drain valves at beginning and end of season.
– Clear surrounding brush and vegetation to prevent intrusion into drains.
Regular maintenance helps prevent major drainage problems and expensive repairs down the road.
Conclusion
Installing proper drainage for your outdoor shower involves important considerations – the type of shower and flooring, layout, climate, regulations, and tying into existing plumbing. Careful planning is needed to select the best drain style and size to keep water flowing away efficiently. Ongoing maintenance protects your investment. With the right drainage plan tailored to your unique space and needs, you can enjoy your open air shower for years to come.