Blanco Home Additions & ADU Nationwide

Blanco Home Additions & ADU: The Mountain View Owner’s Guide

Blanco kitchen and bath fixtures are specified in roughly half the ADUs and home additions we build in Mountain View, where the brand’s German-engineered drains, strainers, and mounting hardware hold up better than standard builder-grade alternatives in our hard water. A full Blanco-compatible installation in a Mountain View addition or ADU kitchen typically runs $45,000-$130,000 depending on square footage, structural work, and whether we’re tying into existing sewer and gas lines. We stock Blanco strainer baskets, flange assemblies, and quick-connect fittings on our Mountain View trucks, and we can source same-day from our San Jose supplier for anything else.

Call (669) 215-4852

Most Mountain View homeowners realize something’s wrong when the Blanco strainer starts leaking under the sink during the final inspection walkthrough, or when the mounting clips fail to seat properly on a granite composite sink in a Castro Street rental unit we’ve converted. The symptoms look minor until you pull the cabinet and find water staining the subfloor.

Which Blanco Models This Applies To

Blanco makes three product families relevant to Mountain View additions and ADUs: the Silgranit composite sinks (PuraDur II and PuraDur III finishes), the stainless steel Precision and Andano series, and the older Classic line still found in pre-2015 Mountain View ranch remodels. The strainer assembly part number lives on a sticker under the sink rim, but it’s often obliterated by caulk or cleaning products. If you can’t read it, measure the drain opening: Silgranit sinks take a 3.5-inch flange, while the older Classic stainless sinks sometimes spec a 4-inch European thread that doesn’t cross over.

We source OEM Blanco strainers (part 441231 for Silgranit, 440029 for stainless) and also carry a quality aftermarket equivalent from Plumb Pak that meets the same 304 stainless spec at roughly 60% of OEM cost. The catch in Mountain View’s hard water is the rubber gasket: OEM Blanco uses EPDM, which outlasts the Buna-N compound in most aftermarket units by about four years here. We note which we’re installing on the written quote, so there’s no substitution surprise.

Signs Your Blanco Home Additions & ADU Is Failing

• Standing water in the sink that drains slowly despite a clear P-trap. The Blanco strainer basket’s silicone seal has hardened or the pivot rod connecting the lift handle to the stopper has corroded at the joint. In Mountain View, we see this at year six or seven on rental ADUs where tenants run the disposal without enough water flow.
• Water staining the cabinet base or drywall below. The flange gasket between the sink body and the strainer body has failed, usually from overtightening during original installation or from thermal cycling in an uninsulated garage ADU. The leak is intermittent until the particleboard swells.
• The strainer body spins freely when you try to tighten or remove it. The locknut threads have stripped, often because a previous installer used channel locks instead of the proper strainer wrench and cross-threaded the nylon insert. This is a full replacement, not a tightening fix.
• Granite composite sink shows a hairline crack radiating from the drain opening. Blanco Silgranit is resilient, but thermal shock from pouring boiling water directly into a cold sink, or from an improperly supported garbage disposal hanging off the strainer, will stress the composite. The crack propagates to the flange seat and the seal fails.
• Musty odor from the cabinet that returns after cleaning. The strainer flange gap is allowing sewer gas past the water seal in the P-trap, usually because the rubber gasket has shrunk or the plumber’s putty application was skimped during the original rough-in. Mountain View’s older sewer lines with occasional pressure fluctuations make this worse.

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Replacement Cost & What’s Included

For a Blanco strainer or flange replacement in an existing Mountain View addition or ADU, expect $280-$520 installed. That covers removal of the failed assembly, inspection of the sink body for cracks or delamination, installation of the new strainer with fresh plumber’s putty and a reinforced gasket, reconnection of the P-trap and disposal if present, and a leak test with documented photo record. If the sink body itself is cracked, replacement pushes the job into our Kitchen Remodel range at $14,000-$45,000, though most strainer failures don’t require that.

What drives the range: disposal removal and rehang adds 45 minutes; Silgranit sinks need a specialized friction wrench to avoid marring the finish; and some Mountain View ADUs built in the 2019-2021 rush have inaccessible plumbing behind IKEA cabinet systems that weren’t designed for service access. We put the exact scope and price in writing before starting, per Clause 1 of the Haven Standard. The 365-Day Done Right Promise covers the installation, and the OEM Blanco strainer carries its own 10-year warranty against manufacturing defect.

DIY or Call Us?

There’s nothing inherently dangerous about a strainer replacement, but there are three ways DIY goes sideways in Mountain View’s housing stock. First, the Silgranit finish scratches if you use a standard spud wrench, and we’ve had homeowners call us after gouging a $900 sink to save $200 on labor. Second, the disposal hang weight needs to be supported during strainer removal, or the torque will crack the sink body. Third, Mountain View’s 2019 plumbing code amendments require a dishwasher air gap on new and replacement installations in ADUs, and inspectors flag its absence even on a strainer swap if the cabinet’s opened up.

What you can safely check: verify the leak is at the strainer, not the supply lines or the disposal discharge hose, by running water with a flashlight under the cabinet. If the water tracks to the strainer flange, you’ve identified the right part. From there, call (669) 215-4852 and we’ll schedule a free estimate with a written price before any work starts.

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