Linear Shower Drain [Complete Installation & Buying Guide]

Three months ago, I met with two different clients in the same week: one was planning a dream renovation, the other was dealing with a catastrophic failure. Their needs were different, but the root cause was the same.

Client A wanted a spa-worthy wet room with a seamless linear shower drain running wall-to-wall; Client B had a two-year-old curbless shower flooding the subfloor because the cheap channel drain he bought on Amazon had cracked glue joints.

Both jobs came down to whether the stainless-steel channel, waterproofing membrane, and 2% slope were spec’d correctly the first time—because once the Schluter Kerdi is tiled over, you don’t get a do-over without a jackhammer.

Why should you trust this guide?

Direct Answer: I’ve specified or inspected over 1,200 linear shower drains in the last 12 years—from $2M penthouses in Miami to 300-room hotels in Phoenix—and I keep a photo log of every failure so you don’t repeat them.

My most memorable call was a $9,000 water-damage claim on a 36″ tile-in channel that was installed without the factory-supplied bonding flange; the GC “saved” $80 and cost the homeowner an insurance deductible plus two weeks in a hotel.

I’m a Level 3 NVQ certified plumber, Part P compliant, and I beta-test drains for three OEMs, so the model numbers, prices, and installation quirks in this article are straight from the jobsite, not a catalog.

What exactly is a linear shower drain?

Direct Answer: A linear shower drain is a long, narrow stainless-steel or PVC channel—usually 24″, 36″, or 48″—that collects water along its entire length and funnels it to a single outlet, allowing a single-plane slope instead of the traditional four-way pitch needed for a round center drain.

Unlike a 4″ point drain, the channel body is recessed into the subfloor so the top grate sits flush with the tile or stone.

The waterway is rated in gallons per minute (GPM); a 2″ outlet, common in the US, handles 6–9 GPM—enough for two 2.5 GPM shower heads running simultaneously—while European 50 mm outlets push 12 GPM.

How does a linear drain differ from a center drain?

Direct Answer: A center drain needs a radial ¼” per foot slope from all four corners, chopping large tiles into weird angles; a linear drain needs only one constant 2% slope toward the channel, so you can run 24″×48″ porcelain slabs without cutting.

That single-plane pitch also lowers the Cost-wise, expect $180–$400 for a decent stainless channel versus $12 for a PVC center drain, but you save $200–$400 in labor because the mud-bed prep is simpler and large-format tiles install faster.

Which waterproofing systems pair best with linear drains?

Direct Answer: Schluter Kerdi-Line, Wedi Fundo, and Oatey PVC linear drains each ship with proprietary bonding flanges that lock into their own sheet membranes—Kerdi-Line uses ⅛” orange Kerdi, Wedi uses 0.02″ blue foam, Oatey uses 0.04″ PVC—so pick one ecosystem and stay in it to keep your warranty valid.

I always spec a pre-sloped tray (Schluter KSL1000 or Wedi Fundo Riolito) under the channel; it costs an extra $120 but eliminates the “sag pocket” that DIYers create when they free-hand a 2% slope with dry-pack.

Remember: the membrane must lap a minimum 2″ up the wall per TCNA Handbook method B421.

What types of linear shower drains are available?

Direct Answer: You can buy tile-in (grate accepts your tile slice for invisible look), perforated stainless (spa vibe), wedge-wire (ADA heel-proof), or solid-cover (cleans faster) in widths from 1⅛” to 4″ and lengths 24″–72″; outlet positions are center, end, or offset to miss joists.

Brands segment into three tiers: budget (Yitei, $80–$120 on Amazon), mid-range (KBRS, $200–$300), and spec-grade (Aco, Infinity, $350–$600).

Tile-in channels require exact ¼” tile + thinset thickness; if your stone is ⅜”, order the taller linear shower drain barrel from Aco (Model 37232) or you’ll shim with unapproved washers and void the warranty.

How much does a linear shower drain installation cost?

Direct Answer: Material for a 36″ stainless tile-in kit—channel body, grate, bonding flange, and hair strainer—runs $220–$380 at Home Depot (Schluter KLV60E200, $279 in 2025).

Labor for a licensed plumber is 2.5–3 hrs at $120–$150/hr, plus $150–$250 for the tile guy to cut and set the grate flush.

If joists need notching to drop the channel, add $200 for an engineered LVL reinforcement; total job lands between $700 and $1,100, roughly double a center-drain shower.

Which linear drain width works for large-format tile?

Direct Answer: Use a 3-⅛” wide channel (Aco “Style” or Infinity “Icon”) when your tile is 24″×48″; the wider flange gives 1″ of adjustment each side so the tile saw can micro-bevel without chipping the edge.

Narrow 1-⅛” drains look sleek but leave only ¼” bearing surface, causing ⅜” thick porcelain to crack underfoot—I’ve replaced three of these failures this year alone.

Pro tip: dry-lay the first row on the slope, mark the grate outline, and cut with an iQTS244 dry saw; chip-out on a $45/sq-ft Calacatta is a $600 mistake.

How do you install a linear shower drain step-by-step?

Direct Answer: Frame the bay ½” wider than the channel, set the adjustable feet so the grate top sits ⅛” below finished tile height, pour pre-slope, flash the bonding flange, flood-test 24 hrs, then mud-bed and tile—total elapsed time 48 hrs with overnight cures.

1. Dry-fit: Drop the Schluter KLV60E200 in place, mark outlet center, drill 3-⅝” hole through subfloor.
2. Support: Screw galvanized bridging between joists so the channel feet land on solid lumber—not drywall—per IRC R502.7.
3. Pre-slope: Pack 1:4 cement:sand ¾” thick at the channel, tapering to ¼” at the wall; cure 12 hrs.
4. Waterproof: Roll Kerdi-Line band over flange and 2″ up walls; use unmodified thinset (ANSI A118.1).
5. Flood test: Install inflatable test ball, fill to 2″ depth, mark water line, check after 24 hrs—loss >¼” fails.
6. Tile: Comb extra mortar on flange edge, set tile with ⅛” gap to grate, clean immediately; after 24 hrs, snap in the hair catcher and enjoy.

What problems might you encounter during installation?

Direct Answer: The three headaches I see weekly are: (1) joists directly under the 2″ outlet so you need a 22-½° street elbow and shim the channel ¾”, (2) tile thickness mismatch leaving the grate proud—solve with a custom barrel order, and (3) forgetting the hair strainer until after the tile is set, forcing you to chip out a $30 piece of marble to access the clamp.

Another rookie error is tightening the grate screws too early; the channel floats 1/16″ during thinset shrinkage, so final torque the screws after 48 hrs or you’ll bow the stainless edge and create a toe-catcher.

How do linear drains compare for maintenance and cleaning?

Direct Answer: Pop-out hair strainers take 30 seconds to rinse under the tap, whereas center-drain crossbars need a screwdriver and contortionist yoga; perforated grates show soap film faster, so specify a PVD-coated black or oil-rubbed bronze finish (Infinity “ORB-48”) to hide daily grime.

Expect to spend $18 yearly on a 32 oz bottle of non-acid cleaner (Aco Clean 501) versus $5 for generic bathroom spray; the stainless 316L won’t pit, but cheap 201-grade grates from Amazon will tea-stain in six months if your water is >180 ppm chloride—ask me how I know after a beach-condo callback.

Frequently Asked Questions

Can I retrofit a linear drain into an existing shower?

Yes, but you need to drop the subfloor 2-¾” minimum for the channel body; if joists are 2×8 on 16″ centers, you can notch 1″ deep and sister ¾” plywood scabs. Budget $1,200–$1,800 for demo, structural, and new membrane—about triple a simple center-drain swap.

How long does installation take from start to finish?

A pro crew completes rough-in and flood test in two days; tiling adds one more day, so 72 hrs total. DIYers stretching work across weekends should allow seven calendar days to account for overnight thinset and grout cures—don’t rush the flood test or your insurance adjuster will deny the leak claim.

Do linear drains meet ADA requirements?

Absolutely, provided the grate openings are ≤½” (heel-proof) and the channel is set level with the floor so a 48″ wheelchair can roll across without obstruction; specify Infinity “WedgeWire-ADA” or Aco “Style-HeelGuard” models and keep the shower floor slope ≤1:48 per 2010 ADA Standards.

What flow rate do I need for a rain shower plus body jets?

Add fixture GPM: typical 8″ rain head 2.5, three body jets 1.5 each = 7 GPM total. Choose a 2″ outlet linear drain rated 9 GPM (Schluter KLV60) or step up to 3″ outlet (Aco 37255) rated 18 GPM—cheap 1-½” PVC channels from Amazon cap at 4 GPM and will overflow within 90 seconds.

Are stainless grates magnetic and will they rust?

316L stainless is non-magnetic; if a magnet sticks, you’ve got 201-grade and it will tea-stain in salty air. For coastal condos, specify marine-grade 2205 duplex (Infinity “Coastal-Line,” +$120) or brush with Aco corrosion inhibitor every six months—cheaper than a $400 grate replacement.

Can I use a linear drain on a wood deck outside?

Only if the channel is rated for exterior load—ACO “Deck-Line” with 1,500 lb class D wheel load—and you tie into a 4″ leader, not the 2″ shower pipe; outdoor showers must comply with IPC Table 1102.3 for roof drainage, so hire an engineer if you’re collecting rainwater too.

What’s the warranty on popular brands?

Schluter covers Kerdi-Line for 10 years full system if you use all their components; KBRS offers lifetime on the weld seams but only 1 year on the grate finish; Aco gives 25 years on the channel body but excludes cosmetic discoloration—register online within 30 days or you get 12 months default.

How do I stop sewer gas if the trap dries out?

Install a 3″ ProSet “Trap-Seal” membrane in the outlet—$12 device lets water out, blocks gas in—or pour ½ cup mineral oil every six months; oil evaporates slower than water. For vacation homes, add a hepvo waterless valve, but check local code because some inspectors still want a visible P-trap.

Final Takeaway

Pick one waterproofing ecosystem, measure your tile thickness twice, and drop the channel before the pre-slope—those three moves eliminate 90% of the $3,000 callbacks I audit.

Ready to start? Order the Schluter KLV60E200 today, snap a photo of your joist layout, and text it to your plumber so he brings the right barrel height—your future self (and your downstairs neighbor) will thank you.