Delta Home Additions & ADU Nationwide

Delta Home Additions & ADU: The Miami Owner’s Guide

Delta-compatible fixtures and hardware for home additions and ADUs in Miami typically run $531-$1,534 per installed unit, with full ADU plumbing packages starting around $5,310. We stock Delta trim kits, rough-in valves, and Cartridges for the Monitor and Trinsic series on our trucks, and most replacements are completed in a single visit. Most Miami owners discover a Delta fixture is failing when the shower valve drips through the ceiling of the new addition below, or when the ADU tenant reports pressure that drops to a trickle during the morning rush.

Call (786) 321-4970

Which Delta Models This Applies To

The Delta parts we install most often in Miami home additions and ADUs fall into three product families. The Monitor series (1300/1400 and the newer 1700 series) uses a cylindrical pressure-balance cartridge, RP19804 for the older brass stem and RP46074 for the current plastic-body version. The Trinsic, Cassidy, and Lahara collections share the MultiChoice universal rough-in valve (R10000-UNBX or -IP), which lets us swap trim styles without tearing into the wall. The Delta Classic and Foundations lines, common in budget-conscious ADU builds, use a simpler washerless cartridge that costs less but wears faster in Miami’s hard water.

To identify your part, remove the handle and look for the model sticker on the valve body, or measure the cartridge stem: 1300-series cartridges are 3-3/8 inches long with a flat D-shaped key, while 1700-series units run 4-1/2 inches with a diamond-shaped broach. We source OEM Delta cartridges through Ferguson and Winnelson Miami, though for discontinued models we sometimes spec a quality aftermarket equivalent from Danco. The aftermarket saves $40-$80 on the part but carries a 1-year warranty instead of Delta’s lifetime on OEM. In Coral Gables and Pinecrest, where owners often want matching finishes across main house and ADU, we stick with OEM to guarantee the brushed nickel or champagne bronze matches lot-to-lot.

Signs Your Delta Home Additions & ADU Is Failing

• Shower temperature swings from hot to cold when a toilet flushes. The pressure-balance cartridge has lost its piston seal, usually from scale buildup in Miami’s limestone-heavy water supply. The cartridge can no longer react fast enough to pressure drops, so the mixed water temperature drifts.
• Handle gets stiff or grinds when turned. Calcium deposits from Dade County’s 180-220 ppm hardness rating crystallize between the cartridge body and the valve bore. Left alone, the owner forces it and cracks the ceramic disc or snaps the brass stem.
• Drip from the showerhead or tub spout when the valve is off. The rubber seats and springs (RP4993) have hardened, or the cartridge O-rings have flattened. In ADUs that sit vacant between tenants, the dry rubber degrades faster than in occupied main houses.
• Water seeping through the drywall below a second-story addition. The valve body itself has cracked at the solder joint, or the plaster guard was omitted during rough-in and the escutcheon plate never sealed against the tile. This is the failure that costs $2,000-$5,000 in drywall and paint, not $180 in parts.
• Reduced flow after a pressure-washing or irrigation repair. Debris stirred up in the municipal main has lodged in the cartridge inlet screens. Delta’s design includes removable screens, but in the R10000 rough-in they’re tucked behind the cartridge and easy to overlook during a quick cleaning.

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After

Replacement Cost & What’s Included

These prices include the part, labor, disposal of the old cartridge, and a pressure test before we leave. What drives the range: wall access (tile vs. fiberglass surround), whether the valve body itself needs replacement, and whether the finish is stocked locally or special-ordered. Under Clause 1 of the Haven Standard, you get the written price before we touch a tool. The 365-Day Done Right Promise covers the installation; OEM cartridges carry Delta’s lifetime warranty to the original purchaser, which we register for you. Aftermarket parts carry our 1-year labor warranty.

DIY or Call Us?

There’s a safe middle ground here. A homeowner with a set of Allen keys and a flashlight can pull the handle, remove the retaining clip, and extract the cartridge for identification. Bring it to Ferguson on NW 36th Street and they’ll match it. What goes wrong: the cartridge breaks off in the bore, the retaining clip drops down the wall cavity, or the valve body cracks when the homeowner applies heat to free a seized cartridge. In Miami’s older additions, particularly in Coconut Grove and the Roads, galvanized supply lines behind the valve complicate every step.

We don’t recommend torch work or cartridge extraction with a puller unless you’ve done it before. The cartridge puller costs $35; our service call includes it, plus the documented photo record of what we found inside your valve. If you’ve got a dripping Delta in a finished addition ceiling, the risk of a $200 DIY attempt becoming a $3,000 drywall repair is real. Call (786) 321-4970 and we’ll schedule a free estimate, measure twice, write it down, then build it.

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