Island Tub Drain™ (Testable Rough-in)

Island Tub Drain™ (Testable Rough-in)
Tub Drain

Now featuring a snap-off Test Cap and an asymmetrical Deck Plate designed not to interfere with a freestanding faucet rough-in!

Install a Freestanding Bathtub in minutes…

No muss. No fuss. No kidding.

Your job just got easier.™

tub drain, tub seal, reducing bushing, tailpiece, rubber seal


Now Island Tub Drain™ features a snap-off Test Cap.  Firmly grip the centre Tab with a pair of Channel Locks and rock back and forth until removed.  The Test Cap also keeps dirt and debris out of the Drain during rough-in.

Then, attach the correct Tailpiece (supplied) or Adaptor Kit (also supplied) to the bath drain and lower the tub into the specially designed rubber seal.

“I used this OS&B Island tub drain for a free standing tub a couple of weeks ago.  It was a little on the pricey side but the install time saved and the ease of use made it well worth the while.  I highly recommend it.  So far I have not found an easier way to install a freestanding tub drain.”

— Robert J. Finn - Plumber


  • Newly redesigned Asymmetrical 18 Gauge Epoxy coated Metal Deck Flange – makes installation in tight spaces easier
  • Built-in Snap-off Test Cap – allows for water/air/smoke testing (Rated to 30psi)
  • ITD35 is a Freestanding Tub rough-in (install before tile installation) – access below fixture not required
  • Low profile design – allows for installation in 8” joist space or greater

Installation Tips

  • Use 5” hole saw to cut sub floor (not included). Cutting template included
  • Secure Deck Flange with 6 screws (not included)
  • Do not cut the brass Tailpiece as this may cause a leak
  • NOTE: Island Tub Drain™ is NOT FOR USE with liquid applied or sheet membranes
  • NOTE: Island Tub Drain™ must be installed in a dry area with no potential of water contact


  • 2 x Brass Tailpieces (Fine Thread and Flanged)
  • ABS or PVC Adapter Kit (attaches Island Tub Drain™ to ABS or PVC Bath Wastes)
  • Island Drain assembly with 1-1/2” DWV ABS Tailpiece
  • 2” x 1-1/2” ABS Reducing Bushing
  • Cutting template
  • Mortar/Tile Guard


Island Tub Drain™ Sideview Rendering Island Tub Drain™ Fine Thread Tailpiece Island Tub Drain™ Flanged Tailpiece Island Tub Drain™ ABS Adapter Kit

Fine Thread Tailpiece

Attaches to 314 Series Direct/Offset Bath Wastes and Integral Bath Wastes.

Flanged Tailpiece

Attaches to 314DC Series Cable-Drive® Bath Wastes and Integral Bath Wastes.

ABS or PVC Adapter Kit

Attaches to ABS or PVC Bath Wastes and includes Brass Nut and Poly Washer.

Product Literature

Freestanding Bath Tub Drain, Island Tub Drain™ Freestanding Bath Tub Drain, Island Tub Drain™, ITD35, ITD5135 Cast Iron Island Tub Drain™, Freestanding Bath Tub Drain, Island Tub Drain™, Testable Rough-in Island Tub Drain™., ID357 Freestanding Bath Tub Drain, Island Tub Drain™ Installation, Installation Instructions for Island Tub Drain™


OS&B™ is a Registered Trademark of Oakville Stamping and Bending Ltd.

Island Tub Drain™ is Patented in Canada and the United States of America.

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