The rough in measurement for a shower valve refers to the distance between the center of the shower valve and the finished wall. This measurement is important to get right during the planning and installation of a new shower because it will determine how far the valve and shower head extend out from the wall. Having the correct rough in measurement allows the shower system to be installed and function properly.
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Standard Rough In Measurements
The most common rough in measurement for a standard shower valve is 12 inches. This means from the center of the valve to the finished wall surface there will be a 12 inch distance. Here are some key points about the 12 inch rough in measurement:
- It allows enough space for the valve and piping to be installed while keeping the valve easily accessible.
- Provides a good balance between having the shower head extended from the wall while still feeling immersed in the water stream.
- Works well for most common shower valve types like single handle, dual handle, and pressure balanced valves.
- Accommodates most standard size shower arms and shower heads.
- Keeps the valve safely away from the direct water stream to prevent malfunction.
The 12 inch measurement is the most widely used for shower valve rough ins because it fits well in most shower stalls and bathtub shower combinations. Many plumbing codes require a minimum of 12 inches. It is a versatile measurement that allows some flexibility in the finished look and function of the shower.
Other Common Rough In Measurements
While 12 inches is the standard, some shower valves can be roughed in at other measurements. Here are some other common rough in distances:
- 10 inches – Allows for a more compact shower area but restricted valve space.
- 11 inches – Minimizes protrusion from the wall but less space to work.
- 14 inches – Provides more room for the valve and accessories.
- 16 inches – Allows for a rain shower head extension arm.
- 18 inches – For a complete rain shower experience and accessories.
The rough in can also be adjusted slightly from the valve center to accommodate the desired tile thickness. For example, a 12 inch rough in could be measured from the back of the finished wall instead of the valve center.
Roughing In a Shower Valve
When planning the rough in for a shower, here are some key steps:
- Choose a shower valve and decide on the rough in distance.
- Determine the shower head location height based on the valve location.
- Map out the areas for the valve and piping routes.
- Install blocking and supports before framing the shower walls.
- Run piping to the valve location and leave room for finished wall depth.
- Secure the shower valve in place temporarily until the finished wall is complete.
- After tiles and wall materials are added, attach the valve and shower head.
- Test the valve and shower head function before completing the installation.
The rough in phase is crucial because all subsequent installation and finishing steps depend on the valve being positioned correctly behind the wall. Professional expertise is recommended, especially for first-time homeowners or anyone uncomfortable working with plumbing and framing.
Adjusting an Improper Shower Valve Rough In
If the rough in measurement for the shower valve ends up being inaccurate, there are some ways to remedy or work around the improper positioning:
- Add spacers or fur out the framing to move the finished wall surface to match the rough in.
- Use an extension kit for the valve to make up small gaps in the rough in dimension.
- Rotate the shower arm to angle the shower head toward the user if roughed in too far.
- Replace the valve with one that has adjustable parts to make up for being roughed in too close.
- Reposition or add blocking and reframing to move the valve if very inaccurate.
With small rough in errors under an inch or two, simple adjustments like spacers or extension kits can often resolve the problem. For larger inaccuracies, more work reframing may be required to get the valve positioned correctly behind the wall. Consulting a professional can help determine the best solution.
Roughing In Shower Valves in Specific Applications
While the standard 12 inch rough in will work for most shower installations, some applications call for adjusted measurements:
Bath and Shower Combinations
For a tub shower combo, the rough in often needs to be less than 12 inches to allow room for both the tub spout and shower head. A 10-11 inch rough in is common to keep these components balanced.
Small Shower Stalls
In a small fiberglass or tile stall shower, a 10-11 inch rough in may be required to keep the shower head, walls, and user all in close proximity.
Rain Shower Heads
A rain style shower head on an extension arm will need a 14-16+ inch rough in to provide enough space for overhead water coverage. The rough in can be 20 inches or more for a specialized rain shower.
ADA Showers
For maximum accessibility in an ADA shower, the rough in often needs to be 11 inches or less so the valve and controls are within reach.
Secondary Shower Controls
If adding a secondary control for functions like temperature or volume, the rough in may need to be increased to 16 inches or more to accommodate both valves.
The rough in can be adjusted from the standard for specialized shower types or features. The key is making sure the rough in allows proper operation and accessibility given the design and space.
Checking Rough In Dimensions
When planning the rough in for a shower valve, there are some key measurements to check:
- Valve to finished wall distance – Rough in based on chosen valve.
- Pipe positions – Ensure supply and drop lines are in the proper location.
- Shower head height – Set per preferences but often 6 feet.
- Control locations – Place where accessible by users.
- Finished fixtures – Check dimensions of fixtures to fit the rough in.
- Stud positions – Confirm blocking and framing will work.
- Wall thickness – Account for the depth of the finished wall material.
Taking accurate measurements at each phase from framing to finishing ensures all the components come together properly. The rough opening based on the valve should drive all other dimensions. Ongoing checks also allow adjustments if needed.
Tips for Measuring Rough Ins
- Use a framing square and level when laying out the plumbing.
- Double check measurements at each step.
- Account for the thickness of finished materials.
- Mark measurements on framing lumber for reference.
- Consider using rough in guides for convenience.
- Confirm positioning with the valve manufacturer.
Careful rough in measurement provides the foundation for proper shower installation. Periodic measurement checks can prevent costly problems down the road if something is off.
Conclusion
The standard rough in measurement for a shower valve is 12 inches, but allowances should be made depending on the specific shower design. Smaller or larger rough ins may be required based on space, shower head style, accessories, or user accessibility needs. Careful planning, accurate measuring, and checking dimensions at each stage will help ensure a successful rough in for the shower valve. Expert help is advisable for first timers to get the positioning right for all the plumbing and finished fixtures.