| Weed Busters | Weed Busters | — | (510) 568 3122 | Electricians | Dublin · Alameda County | — | — |
| Weeks Electric Works | Stephen L Weeks | — | (510) 504 6481 | Electricians | Oakland · Alameda County | — | — |
| Wei Ming Zhu Construction | Wei Ming Zhu | — | (510) 219 8422 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Wei Wu Construction Company | Wei Quan Wu | — | (510) 220 4848 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Weihua Li | Weihua Li | — | (510) 415 0582 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Weiping Yin Construction Co | Yin Weiping | — | (415) 867 9266 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Weiss Associates | Thomas James Fojut | — | (510) 450 6165 | Other | Berkeley · Alameda County | — | — |
| Weiying Huang | Weiying Huang | 8334551will@gmail.com | (415) 971 6659 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Welch Construction | Steve Owen Welch | — | (415) 425 3263 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Weld-it Unlimited Fabrication | Weld-it Unlimited Fabrication | — | (925) 337 6559 | Other | Livermore · Alameda County | — | — |
| Wellborn Plumbing | Wellborn Plumbing | — | (925) 525 8995 | Other | Oakland · Alameda County | — | — |
| Wellmade Build | Kirill Ostrovskiy | — | (510) 606 1706 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Wellmade Design Build INC | Kirill Ostrovskiy | — | (510) 606 1706 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Wellman Plumbing Co | Joshua Scott Wellman | — | (510) 656-0399 | Other | Oakland · Alameda County | — | — |
| Wellman Plumbing INC | Trevor Christian Wellman | — | (510) 656 0399 | Other | Fremont · Alameda County | — | — |
| Welte Construction INC | William Harvey Welte | — | (510) 614 0800 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Welton Underground | Michael Patrick Welton | — | (925) 948 5855 | Other | Oakland · Alameda County | — | — |
| Wen Zhang Construction Company | Wen Xiang Zhang | — | (510) 918 3288 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Wes Tile | Wes Tile | westilewes@gmail.com | (510) 467 8339 | Other | San Leandro · Alameda County | — | — |
| Wes-co Industries | Zivanovic Zivorad | — | (510) 534 3320 | HVAC | San Leandro · Alameda County | — | — |
| Wesley Construction INC | Daryl Lee Wesley | — | (510) 430 9332 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| West Cal Plastering | West Cal Plastering | — | (209) 321 8099 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| West Cali Builders INC | Carlos Noe Quintanilla Barrera | — | (510) 827 7879 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| West Co Home Improvement INC | Martinez Adriana Ambriz | — | (510) 205 5939 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| West Co Stucco | Michael Douglas West | — | (510) 773 5875 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| West Coast Av & Security INC | Darrin Ralph Windell | — | (925) 829 2406 | Alarm and generators | Pleasanton · Alameda County | — | — |
| West Coast Builders | West Coast Builders | — | (925) 352 4857 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| West Coast Construction | Saleh Jawad | — | (209) 456 0779 | Electricians | Hayward · Alameda County | — | — |
| West Coast Construction | Wai Ming Yan | — | (510) 676 1292 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| West Coast Insulation INC | Sean Trier Rosholm | — | (650) 369 7111 | Other | Hayward · Alameda County | — | — |
| West Coast Overhead Door Company | Ralph Douglas Brotherson | — | (510) 568 4603 | Other | Castro Valley · Alameda County | — | — |
| West Coast Premier Construction INC | Homy Sikaroudi | — | (510) 271 0950 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| West Coast Tile | West Coast Tile | interested@domainmarket.com | (818) 267 4635 | Other | Berkeley · Alameda County | — | — |
| West Coast Wire Rope & Rigging INC | Timothy James Heath | — | (510) 562 2953 | Other | Oakland · Alameda County | — | — |
| West Construction | Richard William West | — | (925) 570 8348 | GC, remodel, ADU | Dublin · Alameda County | — | — |
| West Edge Design | Anthony James Dominski | — | (510) 782 2050 | Other | Hayward · Alameda County | — | — |
| West Plains Remodeling | West Plains Remodeling | — | (831) 324 5480 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| West Side Development INC | Adrian Ignacio Fernandez | interested@domainmarket.com | (510) 566 4072 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Westates Mechanical Corporation INC | Nigel Dybkjaer Cowan | — | (510) 635 9830 | HVAC | Hayward · Alameda County | — | — |
| Westbrae Construction | Mark Christopher Simmons | — | (510) 253 7541 | GC, remodel, ADU | Berkeley · Alameda County | — | — |