Pipe chase drawers
What is a pipe chase drawer? The drawer that clears sink plumbing, by every name
Search for a drawer that fits under a sink and you meet a dozen names for one thing: pipe chase drawer, plumbing drawer, U shaped drawer, notched drawer box. This page is for homeowners and cabinet shops who want the terms sorted out, the geometry in one drawing, and a clear line between what we build online and what we quote.
Quick answer. A pipe chase drawer is a drawer box with a rectangular opening, the chase, cut out of its back so the sink drain and trap pass through the box instead of blocking it. The chase runs the full height of the box and is open at the rear, so the drawer pulls forward and the pipes leave through the back. We build it as our U shaped sink drawer: one notch placed by three numbers, with at least 3 in of drawer on each side of the notch and at least 3 in in front of it, cut to the 1/32 inch in our Las Vegas shop.
Ready to build it? The configurator prices every choice live and draws your box in 3D before you order.
What a pipe chase is
A pipe chase is the space left open so pipes can pass through something that would otherwise block them. In a house it is the boxed channel in a wall or floor that carries drain and supply lines. In a cabinet it is the opening cut out of a drawer box so the plumbing under a sink passes through the drawer instead of stopping it.
A plain drawer box is a closed rectangle, and its back hits the trap long before the drawer front reaches the cabinet. Cut a rectangle out of the back, open at the rear, and the box slides home around the pipes. From above it now looks like a U: a full width front section and a leg on each side of the chase. Every name below describes some part of that shape.
Terminology
Every name for the same drawer
People search for this drawer under at least eleven names, and a few of them also mean something slightly different. Our product name stays U shaped sink drawer; here is what each of the others means and whether it is the drawer we build.
| Name | What it means | Is it this drawer? |
|---|---|---|
| PIPE CHASE DRAWER, CHASE DRAWER | A drawer box with a chase cut out of the back for pipes. In the building trades a chase is any channel left open for pipes or wiring | Yes, this is the drawer |
| PLUMBING DRAWER | Any drawer built to fit around plumbing; in a sink base, a box with one rear notch. Some people mean the whole drawer, front included | Yes. We build the box; the front comes from you or your cabinet shop |
| U SHAPED DRAWER, U DRAWER | The same box named for its plan view: two legs and a front section around the notch | Yes. U shaped sink drawer is our product name |
| UNDER SINK DRAWER, SINK DRAWER, SINK BASE DRAWER | The drawer that replaces the doors under a sink. Usually a U shaped box; sometimes people mean a tip out tray or a roll out tray behind the doors | Yes when it is a full drawer. Trays are on our under sink pull out page |
| NOTCHED DRAWER BOX | A box with a notch. The same words also describe the small notch and hook holes we cut at the back for undermount slides | Yes for the plumbing notch. The slide notch is separate, and one box can have both |
| PLUMBING NOTCH, PIPE NOTCH, DRAIN NOTCH | The opening itself, not the drawer | The same opening: one rectangle, full height, open at the back |
| PLUMBING CUTOUT, PIPE CUTOUT | Also the opening. A closed hole in the bottom cannot pull out past a pipe, so a working cutout is always open at the back | The same opening |
| RECESSED BACK DRAWER, SET BACK DRAWER | A drawer whose back is set forward across part of its width to clear something behind it | Yes when the recess is part of the width. A full width recess is simply a shorter box |
| P TRAP DRAWER, DRAWER AROUND PIPES | Plain language for the same thing | Yes |
One distinction matters. A U shaped box can carry two different notches. The plumbing notch is the big one: 3 to 29 31/32 in wide, the full height of the box, open at the back. The slide notch is the small cut and pair of hook holes at the back of each outer leg that drop the box onto undermount runners such as Blum TANDEM plus BLUMOTION 563. Side mount slides need only the plumbing notch.
How a pipe chase relates to our U shaped sink drawer
It is the same thing. Our U shaped sink drawer is a custom dovetail drawer box with one pipe chase: a full height rectangular notch, open at the back, placed by three numbers you measure from your plumbing. Width, depth and height describe the box, as on any custom drawer box we build, and every size is the outside of the box. Letters match the drawing above.
| Number | What it is | Range | Rule |
|---|---|---|---|
| A, DISTANCE TO NOTCH CENTER | Left outside edge of the box to the middle of the notch | 4 1/2 to 31 1/2 in | Leaves at least 3 in of leg on each side |
| B, NOTCH WIDTH | The open space between the two notch walls | 3 to 29 31/32 in | Widest pipe or fitting in the box height, plus about 1 in each side (our suggestion) |
| C, DISTANCE FROM THE FRONT TO THE NOTCH | Front outside face of the box to where the notch starts | 3 to 27 in | At least 3 in |
| NOTCH DEPTH | Box depth minus C. We calculate it | Follows D and C | At least 3 in |
| W, BOX WIDTH | Outside width, cut to the 1/32 inch | 6 to 35 31/32 in | Side mount: opening minus 1 in. Blum undermount with 5/8 in sides: opening minus 13/32 in |
| D, BOX DEPTH | Outside depth | 9 to 24 31/32 in on side mount; the runner length list up to 30 in on undermount | Equal to the slide length on undermount runners |
| BOX HEIGHT | Outside height | 2 to 12 3/4 in | Top about 1 in below the lowest item over a leg (our suggestion) |
A worked example. A 33 in frameless sink base has a 31 1/2 in opening, so on side mount slides the box is 30 1/2 in wide. A trap running from 13 to 20 in off the left cabinet side has its center at 16 1/2 in; take off the 1/2 in of slide clearance on the left and A is 16 in. The trap is 7 in across, so with about 1 in of room each side B is 9 in. Its front sits 9 in behind the box front line, so C is 8 in and the notch reaches 13 in into a 21 in box. The legs come out 11 1/2 and 10 in. We check your three numbers against your box size before we cut, and contact you if they do not add up.
Have your numbers? Build your U shaped sink drawer in the configurator: the Top view draws your legs, notch and front section like a shop drawing, and a red warning holds Add to cart if any of them would fall under 3 in. Not sure yet? Send us a photo and your measurements through the instant quote.
Where pipe chase drawers are used
Anywhere a drawer wants to be and a pipe already is. The kitchen sink base is the common one, but the same box and the same three numbers solve other cabinets.
| Cabinet | What passes through the chase | What changes |
|---|---|---|
| KITCHEN SINK BASE, 30 TO 36 IN | Tailpiece, P trap and trap arm; a disposal when it hangs into the box height; often a dishwasher drain hose | Notches of 8 to 12 in are typical, guidance only. Box sizes are in sink base drawer sizes |
| BATHROOM VANITY, 24 TO 48 IN | P trap and the pop up drain | A narrower notch and a lower box. See bathroom vanity U shaped drawers |
| BAR SINK AND WET BAR | A small trap, often off center in a narrow cabinet | The 3 in leg rule decides between a U box and a tray |
| LAUNDRY OR UTILITY SINK CABINET | Trap and supply lines | Deep tubs leave less height, so measure the clear height first |
| KITCHEN ISLAND SINK BASE | The trap plus the island loop vent that plumbing codes often call for | The vent loop adds width inside the notch. Measure both edges of everything |
| CABINETS WITH NO SINK | A radiator pipe, gas line, vent stack, duct or conduit dropping through the cabinet | Same box, same numbers. Say what it is in “Plumbing notes (optional)” |
What we build online and what goes by quote
The configurator builds one layout: a single full height rectangular notch, open at the back, anywhere side to side. Every other chase shape goes through the instant quote, because we draw it with you before we cut.
| Layout | Where to order | Why |
|---|---|---|
| ONE FULL HEIGHT RECTANGULAR NOTCH, OPEN AT THE BACK, CENTERED OR OFF CENTER | Configurator | Three numbers place it; the live preview draws it and flags any rule it breaks |
| L SHAPED NOTCH, PARTIAL HEIGHT NOTCH, OR TWO NOTCHES | Instant quote | We draw the layout with you first |
| A CLOSED HOLE IN THE DRAWER BOTTOM | Not built | A drawer with a hole cannot slide past a vertical pipe, which is why every chase is open at the back |
| A LOW NOTCHED TRAY BEHIND THE DOORS | Under sink pull out drawers | Keeps your doors instead of taking a drawer front |
Who needs a pipe chase drawer and who does not
You need one when the sink base is getting a drawer front instead of doors and the plumbing leaves room for two legs. You do not when the doors are staying or the pipes leave no room for a leg.
- Yes: a remodel or new kitchen where the sink base gets one tall drawer front, especially a frameless cabinet with no center stile. Fronts are covered in sink base false front to drawer.
- Yes: plumbing at least 3 in from each cabinet side and 3 in behind the box front line, with nothing over the legs hanging lower than the top of the box. A vanity where the trap is the only obstacle is the easy case.
- Yes: a cabinet shop that wants the box cut to the 1/32 inch and prepped for a named undermount runner, with trade pricing through our wholesale page.
- No: you are keeping the doors. A roll out tray behind them is the fit.
- No: the trap hugs a cabinet side, closer than 3 in, or a filter or hot water tank fills one side. A tray on the open side, a shelf or moving the trap are the answers; all four layouts are compared in sink base storage options.
- Ask first: a 42 in sink base is usually wider than our 35 31/32 in limit, so contact us before you order.
What to pick in the configurator
The configurator uses the same words as this page, so the terms above map straight onto its fields.
- The box. “Width (Inches)” and “Width Fraction” take the outside width after your slide deduction; “Height (Inches)” and “Height Fraction” take the height. Depth goes in “Custom Depth (Inches)” for side mount slides, or “Depth Selection” once you choose an undermount runner.
- The chase. “U notch” is already set to Rectangular U notch, full height. Enter the three numbers in “Distance to notch center (inches, from the left outside edge)”, “Notch width (inches)” and “Distance from the front to the notch (inches)”, each as a whole inch plus a fraction to the 1/32 in, so 17 1/16 in is 17 and 1/16.
- The slide notch. “Notching” stays None for side mount slides such as Würth PRO100. For undermount runners choose Notched & Drilled For Undermount Slides, your runner in “Slide Brand/Model”, for example Blum TANDEM plus BLUMOTION 563, and its front locking devices in “Clips”, such as Blum T51.1901 Clips from our clips and brackets. A runner that is not listed goes under Other or unlisted slide model (I’ll enter it), typed into “Your Slide Brand & Model”.
- Everything else in the cabinet. “Plumbing notes (optional)” takes the disposal, water lines, a dishwasher hose and the height of the lowest item over each leg.
- Wood and bottom. “Select Your Wood Type” offers Baltic Birch (Our Standard), which ships finished, or (Select) Hard Maple, finished or unfinished under “Wood Finish”. Under a sink many people pick the 1/2" Thick White Melamine Bottom in “Drawer Bottom Thickness/Wood Type” because it wipes clean.
The field by field walk through, with every price, is the U shaped sink drawer configurator guide. On a phone, a bar at the bottom of the product page shows the live total while you build.
Pipe chase drawer questions
What is a pipe chase drawer?
A pipe chase drawer is a drawer box with an opening cut out of its back so sink plumbing passes through the box instead of stopping it. The opening, the chase, runs the full height of the box and is open at the rear, so the drawer slides forward and the pipes leave through the back. We build it as our U shaped sink drawer, placed by three numbers and cut to the 1/32 inch.
Is a pipe chase the same as a U shaped drawer?
Yes. A pipe chase is the opening; a U shaped drawer is the box that has one. Cut a rectangle out of the back of a drawer and the plan view is a U, a front section and two legs around the chase. Plumbing drawer, chase drawer, notched drawer box and recessed back drawer are other names for the same box.
What is a plumbing drawer?
Any drawer built to fit around plumbing, which in a sink base means a box with one rear notch around the drain and trap. Some people use the term for the whole under sink drawer, front included. We build the box; the drawer front comes from you or your cabinet shop.
Can you put a drawer around plumbing?
Yes, as long as the plumbing sits at least 3 in from each side of the box and at least 3 in behind its front, and nothing over the legs hangs lower than the top of the box. The notch wraps the drain, trap and trap arm; shutoff valves and anything else must sit inside the notch or above the box.
Can a drawer clear a P trap?
Yes. The P trap is the main reason the chase exists. Measure the left and right edges of the trap and add about 1 in of room on each side, our suggestion, and that is the notch width: a 7 in trap becomes a 9 in notch. The trap arm running to the wall sits in the notch too, because the notch is open at the back.
Can a drawer clear water lines and shutoff valves?
Only if they sit inside the notch or above the box. Supply stops usually sit near the back wall on each side of the drain, so the choices are a notch wide enough to include them, a box low enough to pass under them, or an 18 in slide instead of 21 in so the legs stop in front of them. Moving the stops is a plumber’s job.
Can a pipe chase drawer have two notches?
Not from the configurator, which cuts one full height rectangular notch open at the back. Two notches, an L shaped notch and a partial height notch go through our instant quote: describe the plumbing, send a photo with a tape measure in it, and we work out the layout with you before anything is cut.
Can the notch be on the left or right instead of the middle?
Yes. The distance to notch center places the chase anywhere from 4 1/2 to 31 1/2 in from the left outside edge of the box, so a drain on one side just gives two legs of different widths. Each leg must stay at least 3 in wide, and that is the only limit.
What does a pipe chase drawer cost?
It is priced as a custom dovetail drawer box plus the notch, the configurator shows the live total as you build, and our U shaped drawer cost page has the numbers and three worked examples.
Related reading
- U shaped sink drawers: what we build, sizes for common sink bases, slides and ordering.
- Drawer hits the pipes under the sink: seven situations and the fix for each.
- How to measure plumbing for a U shaped drawer: the three numbers step by step.
- U shaped drawer installation: slides, the cardboard template and the drawer front.
- U shaped drawer with a garbage disposal: sizing the chase around the disposal body.
- Two U shaped drawers in a sink base: the stacked layout and each drawer’s notch.
- U shaped drawer cost: the base, the notch and three worked totals.
Give the pipes a chase and the cabinet a real drawer
Whatever you call it, it is one box with one notch, built to order in our Las Vegas shop from your three numbers and cut to the 1/32 inch. Build yours in the configurator and watch the drawing and the price update with every choice. Lifetime warranty on the wood box and free retail shipping.