Hide Wall Water Pipes (Custom Drywall Chase)

A custom drywall chase hides water-supply pipes behind a clean, finished surface while keeping the plumbing supported and serviceable. Plan its size around fittings, pipe movement, insulation, and any valves that need access. Before closing the wall, check local code, protect pipes from fasteners, add required fireblocking, and verify the plumbing is leak-free.

Do exposed water pipes interrupt the clean look you want? A framed drywall chase can make them nearly disappear, but a neat finish is only successful if the pipes remain safe and reachable. I plan the enclosure around what is inside it first, then choose the simplest shape that fits the room.

The steps below cover planning, framing, code checks, and finishing. Requirements vary by location and pipe system, so use the locally adopted codes and the pipe manufacturer’s instructions as your final guide.

Plan the Chase Around the Existing Plumbing

A drywall chase is a shallow framed enclosure that creates a new wall surface in front of pipes. Its dimensions depend on the full plumbing layout, not just the visible pipe. Measure fittings, supports, valves, and any insulation before setting the finished face or deciding where the framing will go.

Start by identifying the pipe material and diameter. Look for elbows, tees, couplings, shutoff valves, and any joints or components that need service. Check for leaks, loose supports, and signs of corrosion before covering anything. If you are unsure about the pipe type or condition, have a plumber assess it before framing.

Sketch the route from end to end, then measure how far the largest fitting projects from the existing wall. Add room for the required support, pipe movement, insulation where needed, and safe clearance from screws or nails. A tight enclosure can press on pipes or make later repairs difficult.

There is no single code-wide chase width or clearance that works for every pipe. For a basic reference, standard 2-by-4 framing is 3.5 inches deep; adding half-inch drywall makes a roughly 4-inch projection before allowing for uneven walls or plumbing that sits proud of the framing. Treat this as a starting point, not a required size.

Situation	What to measure or allow for	Planning note
Straight run of pipe	Pipe diameter, supports, and wall depth	Confirm the pipe can sit without being pinched.
Elbow, tee, or coupling	The widest and deepest fitting	Size the chase around the fitting, not the pipe alone.
Shutoff valve or serviceable part	Handle movement and hand access	Use an access panel where access is required.
Pipe near an exterior wall	Insulation location and cold-air paths	Keep the pipe on the warm side of the insulation where practical.

I also mark likely fastener locations before framing. This helps prevent a drywall screw from landing near a pipe, especially where a narrow chase leaves little room to work. The next step is to confirm the wall and pipe clearances.

Check Clearances, Access, and Freeze Protection

Clearance means the open space needed around a pipe for safe installation, movement, insulation, and service. Before building, compare the planned framing with the adopted building and plumbing codes, as well as the pipe system’s instructions. A chase is not a reason to block a valve or ignore an unsafe pipe route.

If pipes pass through wood studs, follow the local code limits for bored holes. Under IRC R602.6, a hole in a wood stud is generally limited to 40% of the stud’s depth. Up to 60% may be allowed in qualifying doubled studs, subject to the section’s limits. The hole edge must generally be at least 5/8 inch from the stud edge, or the required steel protection plate must be installed. Confirm the adopted edition and conditions with your local building department.

Where piping is too close to a framing face, IRC R602.6.1 requires protection under specified conditions. The referenced steel plate must be at least 0.054 inch thick, or 16 gauge. Local rules and the exact placement matter, so do not treat any scrap metal strip as an automatic substitute.

Keep required access in the plan. Do not bury a shutoff valve, serviceable fitting, or other component that its listing or applicable code says must remain accessible. An access panel can preserve a clean appearance, but it must be large and well placed enough to reach and operate the component. Check the valve handle’s full travel before closing the chase.

Exterior walls need special care. A chase can put a pipe on the cold side of insulation or create a path for cold air. Keep pipes on the warm side of the thermal envelope where practical, and do not count the chase itself as freeze protection. If the existing route is exposed to freezing, ask a qualified plumber or building professional how to address it before concealment.

Frame, Support, Protect, and Fireblock

A chase frame supports drywall; it should not carry the weight of the plumbing or squeeze it into place. Build around the measured pipe route, secure framing to suitable structure, and keep the pipe supported according to its material and manufacturer. Fireblocking is material installed to slow the spread of fire through concealed spaces.

Lay out the finished face and framing on the wall or floor. Allow space for fittings, pipe movement, and insulation where needed. Avoid fastening into hidden plumbing, and do not force a pipe to bend or shift to fit the enclosure. If framing must cross a pipe route, confirm the detail is allowed and protect the pipe from fasteners as required.

Pipe support rules vary. PEX, CPVC, and copper do not all use the same support methods or spacing. Follow the adopted plumbing code and the pipe manufacturer’s instructions, including guidance for changes in direction and thermal movement. Do not rely on drywall, foam, or the chase framing as pipe support unless the system instructions specifically permit it.

Add nail plates where the code requires protection from fasteners. At floor, ceiling, and other locations specified by the adopted code, install fireblocking around chase penetrations and within concealed spaces. IRC R302.11 covers these requirements, but details depend on the building and the location. Use a material approved for the fireblocking purpose; ordinary expanding foam is not automatically an approved fireblock.

Before drywall, check that the frame is secure and clear of the pipes. Confirm that insulation, if needed, will not be compressed or leave an air path that exposes the plumbing to cold. Keep access panels in the plan, and photograph the finished pipe route so its location is documented after the wall is closed.

Test the Plumbing and Verify Before Drywall

A final pre-close check confirms that the piping is sound, protected, and reachable before drywall hides it. Use the test required for the pipe system and local rules, or have a licensed plumber perform it. Also review supports, clearances, fireblocking, and access panels while every part is still visible.

1. Inspect the route. Confirm pipe material, fittings, supports, valves, and nearby electrical or structural elements. Resolve leaks, damage, or loose supports before concealment.
2. Check framing and protection. Verify stud holes meet the adopted code, add required plates, and confirm that framing does not load or pinch the pipes.
3. Confirm fireblocking and insulation. Seal required penetrations with approved materials. Check that any insulation is correctly placed and does not create a cold-air path.
4. Test the plumbing. Follow the applicable test method for the pipe system and local code. Do not close the chase until the test is satisfactory.
5. Record and close. Photograph the route and note valve locations. Install any required access panel, then hang and finish drywall without driving fasteners into the pipes.

A recurring issue I see is a chase sized to cover only the straight pipe, with no allowance for a larger elbow or a valve handle. The result can look finished but leave the fitting pressed against the drywall or the shutoff impossible to reach. Measuring the whole assembly first prevents that avoidable rework.

Installation Examples: Two Common Chase Problems

These examples show how I apply the same planning steps to different layouts. They are illustrative, not fixed code designs; actual dimensions and requirements depend on the home, pipe system, local rules, and the parts in use.

A vertical pipe at a room corner: When a supply line runs up a corner, I measure the pipe and largest fitting, then plan a narrow box around their full depth. I check whether the route needs insulation or a valve access panel. The finished corner can be crisp, but only if the fittings and fasteners have safe clearance.

A horizontal run near an exterior wall: In this case, the key question is where the insulation and air barrier sit. I would not simply build a cover over the pipe and assume the enclosure keeps it warm. First, I check whether the pipe can remain on the warm side of the thermal boundary. If not, I get qualified advice before closing the wall.

In both situations, the chase shape follows the plumbing and the required access. A wider box may be the safer choice if a fitting or service point needs room. The finish should not dictate a pipe route that creates a code, access, or freeze risk.

Final Checks Before You Close the Chase

A successful enclosure hides the pipes without hiding problems. The key checks are code-compliant framing, correct pipe support, protection from fasteners, required fireblocking, and access to serviceable parts. Confirm each item before drywall, and pause if the route may freeze or the plumbing condition is uncertain.

Use the local building department or a qualified plumber when code details, pipe support, testing, or freeze protection are unclear. Then close the chase only after the plumbing has passed its required check and you have documented the concealed route.

Frequently Asked Questions

These answers cover common decisions when planning a drywall enclosure for water pipes. Local codes, pipe materials, and component instructions can change what is allowed, so confirm project-specific details before framing or covering the plumbing.

How deep should a drywall chase be?

There is no universal required depth. Measure the deepest fitting, support, and any needed insulation, then add clearance so the framing and drywall do not press on the pipe. Standard 2-by-4 framing is 3.5 inches deep before drywall, but some pipe layouts need a deeper chase.

Can I cover water shutoff valves with drywall?

Do not cover a shutoff valve if the applicable code or its listing requires access. Plan an access panel that lets you reach and operate the valve. Check the handle’s full movement before closing the wall, and keep the panel easy to locate after painting.

Do pipes need nail plates inside a chase?

Nail plates are required where adopted code rules call for protection from fasteners. Under IRC R602.6.1, the specified steel plate is at least 0.054 inch thick, or 16 gauge. Confirm local requirements and placement; a plate does not correct an improperly located or oversized hole.

Can I drill through studs to route water pipes?

Stud holes must meet the limits in the locally adopted code. IRC R602.6 generally limits a hole to 40% of stud depth, with up to 60% allowed in qualifying doubled studs under stated conditions. Hole-edge clearance and protection rules also apply. Do not drill structural members without checking first.

How far apart should pipe supports be?

Support spacing depends on pipe material, size, orientation, and the manufacturer’s instructions. PEX, CPVC, and copper systems can have different requirements, so one spacing rule should not be applied to every pipe. Check the adopted plumbing code and the exact product instructions before framing.

Does a drywall chase protect pipes from freezing?

No. A chase can conceal a pipe but does not, by itself, provide freeze protection. A poorly planned enclosure may place plumbing on the cold side of insulation or create an air path. Keep pipes on the warm side of the thermal boundary where practical.

Is expanding foam suitable for fireblocking?

Not automatically. Foam must be specifically approved for the fireblocking use and location under the applicable code. Ordinary expanding foam may not qualify. Check the product listing and local requirements, especially where the chase passes through floors, ceilings, or other required fireblocking locations.

Should I test the pipes before installing drywall?

Yes. Complete the test or inspection required for the pipe system and local code before closing the chase. Also check for leaks, secure supports, required protection, and access to valves. Photograph the route so its location is known after the drywall is installed.

(This article was written by one of our staff writers, Michael Donovan. Visit our Meet the Team page.)