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18 x 12" Rectangular Porcelain Undermount Bathroom Sink with Overflow in White 18 x 12" Rectangular Porcelain Undermount Bathroom Sink with Overflow in White
20 x 16" Rectangular Porcelain Undermount Bathroom Sink with Overflow in White 20 x 16" Rectangular Porcelain Undermount Bathroom Sink with Overflow in White
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20 x 16" Black Rectangular Porcelain Undermount Bathroom Sink with Overflow Drain 20 x 16" Black Rectangular Porcelain Undermount Bathroom Sink with Overflow Drain
21" Rectangular Porcelain Undermount Bathroom Sink with Overflow Drain in White 21" Rectangular Porcelain Undermount Bathroom Sink with Overflow Drain in White
23-3/4" Rectangular Porcelain Undermount Bathroom Sink with Overflow Drain in White 23-3/4" Rectangular Porcelain Undermount Bathroom Sink with Overflow Drain in White
Commercial & Multi-Unit

Undermount Bathroom Sinks for Fabricated Vanity Tops

Undermount bathroom sinks are installed below the countertop to create a continuous vanity surface. This mounting method is commonly specified for multifamily, hospitality, senior-living, and other projects using professionally fabricated stone or solid-surface tops.

Countertop fabrication is the defining project consideration. Verify the sink template, reveal preference, mounting hardware, counter material, bowl dimensions, faucet placement, and service access before the opening is cut.

Allora USA can review the specified undermount model with the fabricator's required reveal, counter material, vanity size, drain location, and mounting condition. If an alternate is considered, we provide model documents and identify differences that could require a new cutout, changed reveal, or revised plumbing position.

Request Project Pricing Send Allora the undermount sink schedule or specified model before fabrication for drawings, alternate comparison, availability, and project pricing.

Coordinate the Undermount Reveal

Specify whether the finished counter edge will use a positive, negative, or flush reveal. The approved detail should be consistent across fabricators and project phases.

Use the Exact Cutout Template

Similar undermount sinks can have different corner radii and flange dimensions. Fabricators should use the current drawing for the selected model, not a generic bathroom-sink template.

Confirm Countertop Compatibility

Review counter material, thickness, support, adhesive, clips, and mounting access. The sink must be coordinated as part of the fabricated vanity assembly.

Protect Faucet and Backsplash Space

The basin position affects the remaining deck area behind the sink. Confirm faucet-hole placement, handle movement, backsplash clearance, and drain alignment before fabrication.

Review Alternates Before Cutting Stone

Do not release an alternate undermount sink on outside dimensions alone. Compare the flange, corner radius, bowl outline, drain location, and cutout before fabrication.

Coordinate Project Pricing with Fabrication

Submit quantities before countertop production so model availability, pricing, and approved drawings can be aligned with each fabricator and project release.

Design Files and Resources for Professionals

TECHNICAL SPECIFICATIONS

At Allora USA, we provide a variety of 3D design files and resources tailored to streamline your specification journey. Our tools are designed to ensure that professionals like architects, designers, contractors, and engineers have everything they need to smoothly integrate Allora USA products into their projects.

Frequently Asked Questions

Undermount requires a polished interior cutout edge — works with stone, quartz, and solid surface vanity tops, not with laminate. Stone fabricators polish the edge during cutout. Verify vanity top spec supports undermount before finalizing the sink schedule.

Undermount is the mid-tier and luxury default — seamless counter-to-sink transition is part of the unit positioning, and the project budget includes stone or quartz vanity tops. Specify top mount for value-tier multifamily and student housing using laminate tops or budget-constrained installations.

White porcelain oval (transitional) and rectangular (contemporary). Both shapes are stocked in matched product families with their top mount counterparts to maintain consistent shape across install types within the project.

Yes. Allora produces ADA-supportive undermount bathroom sinks in matched product families with standard undermount — matched shape, finish, and external dimensions. The shallow-depth ADA basin meets accessibility requirements while maintaining the same vanity fit.

Spec sheets, cutout templates, BIM files, and DXF files are available for every SKU — cutout templates matter especially for undermount because fabricator cutout accuracy determines install quality. Trade accounts request the full documentation package through their Allora Advantage rep.

Stock orders ship same-day when placed before noon EST. Phased project orders are scheduled during spec stage — Allora Advantage members get tier pricing, dedicated rep support, hold-back inventory, and fabricator-direct delivery coordination on undermount specs.

One partner for every phase — from first specification through final delivery.

Same day quotes, in-stock inventory, and dedicated reps keep your project moving on schedule.

Same-Day Quotes

Submit before 2 PM EST and get pricing back the same day to keep projects on schedule.

Project-Volume Pricing

Volume savings with flexible mix-and-match across sinks, faucets and showers.

Project-Ready Inventory

Spec the entire job from one catalog — deep stock across sinks, faucets and showers, ready to order at volume.

Project-Matched Warranty

Warranty coverage matched to your project type, so every build is protected on the right terms.

Reliable Lead Times

Fast shipping with clear arrival dates, so orders land on site when the crew needs them.

Dedicated Account Reps

One expert contact from product selection through installation support.

No minimum order to request pricing Net terms available for qualified accounts

Request Project Pricing

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WHAT OUR CUSTOMERS ARE RAVING ABOUT

We’ve partnered with Allora USA on several residential and commercial projects, and they consistently deliver top-notch products. The variety of styles and finishes they offer ensures that we find the perfect match for each project. What stands out is their attention to detail and quick turnaround times. We consider Allora USA an essential part of our supply chain.

Ryan - Project Manager, Multifamily Project Builder