Bathroom Remodeling Glossary: Terms You Will Hear

Bathroom estimates, drawings and permit papers assume you already know the vocabulary. This glossary defines the terms you are most likely to meet, in plain language and alphabetical order. Where a term has a code or standards meaning, the definition says which one. Each entry links to the guide page that covers the subject, so you can use this page as an index to the Vancouver, WA Bathroom Remodeling Guide.

A

ABS. Black plastic pipe used for drain, waste and vent lines in many houses. You may see it, or older cast iron or galvanized steel, when the floor or wall is opened. See moving bathroom plumbing.

AHERA inspector. A person accredited to inspect buildings for asbestos. Under the Southwest Clean Air Agency's rule, only an AHERA accredited building inspector may determine by inspection that a suspect material is not asbestos. See asbestos in bathrooms.

Allowance. A placeholder amount in an estimate for an item not yet chosen, such as tile or a vanity. If your choice costs more, you pay the difference. See contracts, allowances and change orders.

Alcove tub. A tub set between three walls, finished on one side only. The most common tub in hall baths. See bathtub types.

Anti-scald valve. Common name for a shower valve that limits sudden temperature swings. The standard, ASSE 1016, defines three types: pressure-balancing, thermostatic, and a combination of the two. See shower valves.

B

Backer board. A water-tolerant panel, such as cement board or foam board, installed in place of drywall behind tile. Some kinds still need a separate waterproofing layer over them; foam board systems are designed to be part of one. See waterproofing explained.

Blocking. Solid wood fastened between studs so something heavy can be anchored later: grab bars, a wall-hung vanity, glass hinges or a towel warmer. Cheap to add while walls are open, hard to add afterward. See grab bars and safety hardware.

Bonded membrane. A waterproof sheet or liquid coating stuck directly to the backer or mortar bed, with tile set on top of it. Bonded waterproof membranes for tile are covered by the standard ANSI A118.10.

C

Cartridge. The replaceable part inside a faucet or shower valve that controls flow and temperature. A drip or a stiff handle is often a worn cartridge.

CFM. Cubic feet per minute, the measure of how much air a fan moves. Washington's code requires a bathroom exhaust fan to deliver at least 50 cfm if it runs intermittently or 20 cfm if it runs continuously (WAC 51-51-1505). See choosing an exhaust fan.

Change order. A written amendment to the contract that changes scope, price or schedule, signed before the changed work is done.

Curb. The raised threshold at a shower entry that keeps water in. A curbless shower has none and relies on floor slope instead. See curbless showers.

D

DCOF. Dynamic coefficient of friction, a slip-resistance measure for hard flooring tested under ANSI A326.3. The standard calls for a DCOF of 0.42 or greater on level interior floors expected to be walked on when wet. See bathroom flooring.

Design-build. One company designs and builds the project under one contract. See design-build vs a separate designer.

Disclosure statement. The "Notice to Customer" a Washington contractor must give before starting residential work of $1,000 or more (RCW 18.27.114). It lists the registration number and bond and warns that your property may be liened.

Diverter. A valve or knob that sends water to a different outlet: tub spout to showerhead, or showerhead to handheld or body sprays.

Dual flush. A toilet with a reduced flush and a full flush. For WaterSense, its effective flush volume is the average of two reduced flushes and one full flush.

E

Edge trim. Metal or plastic profiles that finish exposed tile edges at niches, corners and transitions, in place of bullnose tile.

Effective flush volume. The water a toilet uses per flush, averaged for dual flush models. Washington's plumbing code caps it at 1.28 gallons (WAC 51-56-0400, UPC 411.2). See choosing a toilet.

Escutcheon. The decorative plate that covers the hole where a pipe or valve comes through the wall.

Exclusions. The work and items an estimate does not include, such as glass, permits or repair of hidden damage. See comparing estimates.

F

Flange (toilet flange or closet flange). The fitting at the floor that connects the toilet to the drain and anchors it. A cracked or low flange is a common source of leaks at the toilet base.

Flood test. Plugging a finished shower pan or membrane and filling it with water for a period to check for leaks before tile is installed.

Foam board system. Lightweight waterproof panels, seams and a matching pan or curb, sold as a set and installed together as the waterproofing behind tile.

Frameless glass. Shower glass held by hinges and clips without a metal frame around the panels. Like all shower glass, it must be safety glazing. See shower glass and doors.

G

GFCI. Ground-fault circuit interrupter, a receptacle or breaker that cuts power when it detects current leaking to ground, for example through water. Bathroom receptacles need this protection; see bathroom electrical code.

Gpf and gpm. Gallons per flush (toilets) and gallons per minute (faucets and showerheads). Washington's plumbing code limits showerheads to 1.8 gpm at 80 psi and residential bathroom faucets to 1.2 gpm at 60 psi (WAC 51-56-0400). See rebates and water savings.

Grout. The material that fills joints between tiles. Cement grouts (ANSI A118.6 and A118.7), epoxy (A118.3) and pre-mixed grouts (A118.19) behave differently. Grout is not waterproof. See grout and sealing.

H to L

Heated floor. Electric mats or cables set under tile and run from a thermostat. See heated bathroom floors.

Large-format tile. ANSI's terminology standard A108.T defines it as tile with a face dimension greater than 23 inches. Installation rules for offset and grout joints start at tile with a side longer than 15 inches. See large-format tile.

Lavatory. The plumbing code's word for a bathroom sink.

Lien release. A signed document by which a contractor, subcontractor or supplier gives up its right to lien your property for work that has been paid for. Ask for them before final payment. See Washington lien law.

Linear drain. A long, narrow drain, usually at one wall or the entry, that lets the shower floor slope in one direction. That makes large tile and curbless entries easier. See shower pans and bases.

Lippage. The difference in height between edges of adjacent tiles. ANSI A108.02 sets allowable lippage as the tile's own warpage plus a table value.

Liquid-applied membrane. Waterproofing rolled or brushed on in coats over backer board, often with fabric at seams and corners.

M

MaP. Maximum Performance, a voluntary third-party toilet test measuring how much test media a toilet clears in one flush, up to 1,000 grams. It is separate from WaterSense, which sets its own pass or fail test.

Membrane. Any waterproof layer behind tile: a sheet, a liquid coat, or a pan liner under a mortar bed.

Mortar bed (mud bed). A thick layer of sand and cement mortar shaped by hand to slope the shower floor to the drain. In the traditional method it sits over a pan liner (TCNA method B415); in bonded methods a membrane goes on top of it (B421).

N to P

Niche. A recessed shelf built into the shower wall between studs. It must be waterproofed like the rest of the wall. See niches and benches.

P-trap. The U-shaped section of drain under a sink or tub that holds water to block sewer gas from coming into the room.

Pan liner. A waterproof sheet laid under a mortar bed in a traditional shower floor, turned up the walls and curb so water that passes through the grout drains away.

PEX. Flexible plastic water supply tubing used in many remodels in place of copper.

Pre-sloped pan. A factory-made foam or composite shower floor already shaped to fall to the drain, used in place of a hand-floated mortar bed.

Pressure-balancing valve. A shower valve (ASSE 1016 Type P) that holds the hot-to-cold mix steady when pressure changes, such as when a toilet is flushed.

R

Rectified tile. Tile whose edges are machine-cut after firing so sizes are consistent, allowing narrower grout joints.

RES permit. The City of Vancouver's residential building permit. When plumbing, mechanical or electrical work is part of a remodel, the city includes it in the RES. See the city permit process.

Retrofit liner. An acrylic or plastic shell installed over an existing tub or shower base. Covered by the standard IAPMO/ANSI Z124.8. See one-day baths and liners.

Rough-in. The plumbing, wiring and ducting installed inside walls and floors before they are closed, and inspected at that stage. Also the distance from the finished wall to the center of a toilet drain; most toilets are made for a 12-inch rough-in, so measure yours before buying. See bathroom inspections.

S

Safety glazing. Glass that meets impact standards for hazardous locations. Glazing in shower and tub doors and enclosures falls under the federal standard 16 CFR 1201. See safety glass rules.

Slope to drain. The fall built into a shower floor so water runs to the drain instead of pooling.

Sone. A unit of perceived loudness used on fan ratings. HVI says one sone is about the sound of a quiet refrigerator in a quiet kitchen, and the scale is linear: 3 sones is half as loud as 6. See bathroom ventilation.

Specialty plumber. A Washington plumbing certificate that covers plumbing of single-family dwellings, duplexes and apartment buildings up to three stories. See checking credentials.

Substrate. Whatever the tile is bonded to: backer board, a mortar bed, a membrane or concrete.

T

Tempered glass. Heat-treated glass that, under the federal definition, cannot be cut or drilled after treatment and breaks into small particles when fractured.

Thermostatic valve. A shower valve (ASSE 1016 Type T) that holds a set water temperature, and often allows separate control of volume.

Thinset. The cement-based mortar used to bond tile in a thin layer. Common standards are ANSI A118.4 (modified dry-set mortar) and A118.15 (improved modified). See bathroom tile guide.

Trim kit. The visible handle and plate of a shower valve, sold separately from the valve body in the wall. The trim must match the valve.

V to W

Vent (plumbing). Pipes that let air into the drain system so traps are not siphoned dry. Moving a fixture often means moving its vent too.

Wall-hung toilet. A toilet bolted to a frame inside the wall, with the tank concealed behind it. It needs a thicker wall and access for service. See toilets.

WaterSense. An EPA label for water-efficient products. WaterSense showerheads use no more than 2.0 gpm; Washington's plumbing code sets a lower 1.8 gpm cap for installed showerheads.

Wax ring. The seal between the toilet base and the flange. Replaced whenever a toilet is reset.

Wet room. A bathroom where the shower area is open to the room and the floor, and often more of it, is waterproofed. See wet rooms.

Still have a term you cannot place?

Ask the contractor to define it in writing, especially when it affects price. If you are planning a remodel in Vancouver or Clark County, JDI Construction's design team will walk you through the plan and estimate term by term at a free in-home consultation. See our bathroom remodeling service or request a consultation.