| PBPhoenix Brick Yard | Phoenix | AZ | — | ◇ UNVERIFIED |
| PHPine Hall Brick Co., INC. - Plant #7 | Fairmount | GA | — | ◇ UNVERIFIED |
| PRPioneer Roofing Tile INC | Fontana | CA | — | ◇ UNVERIFIED |
| P1Plant 1 Strasburg | Strasburg | OH | — | ◇ UNVERIFIED |
| PAPortobello America, INC. | Cookeville | TN | — | ◇ UNVERIFIED |
| PSPrecasting Site | Jacksonville | AL | — | ◇ UNVERIFIED |
| PTProgressive Technology INC. | Rocklin | CA | — | ◇ UNVERIFIED |
| PGPryor Giggey CO | Chehalis | WA | — | ◇ UNVERIFIED |
| PGPryor Giggy CO | Pueblo | CO | — | ◇ UNVERIFIED |
| PIPyrotek INC | Carlisle | PA | — | ◇ UNVERIFIED |
| PIPyrotek, INC. | Muscle Shoals | AL | — | ◇ UNVERIFIED |
| PIPyrotek, INC. - Neco Division | Salisbury | NC | — | ◇ UNVERIFIED |
| QCQuality Components Framing Systems INC. | Whitesboro | NY | — | ◇ UNVERIFIED |
| QTQuarry Tile CO | Spokane | WA | — | ◇ UNVERIFIED |
| RCRagland Clay Products | Ragland | AL | — | ◇ UNVERIFIED |
| RRRath Refractories | Milledgeville | GA | — | ◇ UNVERIFIED |
| RBRedland Brick | Williamsport | MD | — | ◇ UNVERIFIED |
| RBRedland Brick | Rocky Ridge | MD | — | ◇ UNVERIFIED |
| RBRedland Brick INC /kf Plant | South Windsor | CT | — | ◇ UNVERIFIED |
| RRRed Rock Tileworks Llc | Nashville | TN | — | ◇ UNVERIFIED |
| RTRefine Tile, LLC | Elkton | KY | — | ◇ UNVERIFIED |
| RPRefractory Products CO | Elgin | IL | — | ◇ UNVERIFIED |
| RPResco Products INC | Santa Fe Spgs | CA | — | ◇ UNVERIFIED |
| RPResco Products, INC. | Greensboro | NC | — | ◇ UNVERIFIED |
| RPResco Products, INC. | Tarentum | PA | — | ◇ UNVERIFIED |
| RPResco Products, INC. - United Refractories | Warren | OH | — | ◇ UNVERIFIED |
| RRRhi Refractories - Ione | Ione | CA | — | ◇ UNVERIFIED |
| RBRichards Brick CO | Edwardsville | IL | — | ◇ UNVERIFIED |
| RBRichards Brick Company | Saint Louis | MO | — | ◇ UNVERIFIED |
| RIRichfield INC | City of Industry | CA | — | ◇ UNVERIFIED |
| RMRichland Moulded Brick CO | Mansfield | OH | — | ◇ UNVERIFIED |
| RCRichtex Corporation Ninety Six Plant 9 | Ninety Six | SC | — | ◇ UNVERIFIED |
| RTRipon Truck Repair & Equipment, LLC | Pickett | WI | — | ◇ UNVERIFIED |
| RRRiverside Refractories INC | Pell City | AL | — | ◇ UNVERIFIED |
| RMRjf Morin Brick, LLC | Auburn | ME | — | ◇ UNVERIFIED |
| RCRme Construction Supply CO Ltd, INC. | Kahului | HI | — | ◇ UNVERIFIED |
| RCRoeben CO INC | Carpenter | NC | — | ◇ UNVERIFIED |
| RRRubicon Refractories Inc | Hammond | IN | — | ◇ UNVERIFIED |
| RIRub-r-tek INC | Olney | IL | — | ◇ UNVERIFIED |
| RCRuby Clay Company LLC | Tulsa | OK | — | ◇ UNVERIFIED |
| SCSaint-gobain Ceramics/latrobe Plt | Latrobe | PA | — | ◇ UNVERIFIED |
| SISaint-gobain Industrial Ceramics | Huntsville | AL | — | ◇ UNVERIFIED |
| SJSaint Joe Brick Works INC | Pearl River | LA | — | ◇ UNVERIFIED |
| SJScott Jewett Truck Line INC | Mangum | OK | — | ◇ UNVERIFIED |
| SCSelee Corporation | Hendersonville | NC | — | ◇ UNVERIFIED |
| STSeneca Tiles INC | Attica | OH | — | ◇ UNVERIFIED |
| SIServsteel Inc/morgan | Morgan | PA | — | ◇ UNVERIFIED |
| SGShamrock Group Mexico Plant | Mexico | MO | — | ◇ UNVERIFIED |
| SSSheridan Supply CO - Newmanstown | Newmanstown | PA | — | ◇ UNVERIFIED |
| SCSika CORP Milpitas | Milpitas | CA | — | ◇ UNVERIFIED |
| SRSimister Rental LLC | Santaquin | UT | — | ◇ UNVERIFIED |
| SISlowfire, Inc. | Portland | OR | — | ◇ UNVERIFIED |
| SBSnyder Brick and Tile | Snyder | TX | — | ◇ UNVERIFIED |
| SCSoCal Crushing Inc. | Sun Valley | CA | — | ◇ UNVERIFIED |
| SBSouthern Brick and Tile Company | Byhalia | MS | — | ◇ UNVERIFIED |
| SVSteel Valley Refractories, LLC | Lowellville | OH | — | ◇ UNVERIFIED |
| SCStone Creek Brick CO | Stone Creek | OH | — | ◇ UNVERIFIED |
| STSummitville Tiles INC | Summitville | OH | — | ◇ UNVERIFIED |
| TCTaylor Clay Products, INC. | Salisbury | NC | — | ◇ UNVERIFIED |
| TCTexas Clay Plant | Malakoff | TX | — | ◇ UNVERIFIED |
| UIUni-ref INC | Sharonville | OH | — | ◇ UNVERIFIED |
| UIUni-ref INC. | Birmingham | AL | — | ◇ UNVERIFIED |
| UMUniversal Materials INC | Mogadore | OH | — | ◇ UNVERIFIED |
| UTUsb Tennessee LLC - Gleason | Gleason | TN | — | ◇ UNVERIFIED |
| UGUS Gypsum - Norfolk Plant | Norfolk | VA | — | ◇ UNVERIFIED |
| USU. S. Refractories | Hitchins | KY | — | ◇ UNVERIFIED |
| URU.S. Refractory Products, LLC | North Ridgeville | OH | — | ◇ UNVERIFIED |
| UIUst, INC. | Mount Pleasant | TN | — | ◇ UNVERIFIED |
| VLVanDillion, LLC | Minneapolis | MN | — | ◇ UNVERIFIED |
| VAVeitsch-radex America INC | Saint Charles | MO | — | ◇ UNVERIFIED |
| VBVermont Brick Manufacturing LP | Highgate | VT | — | ◇ UNVERIFIED |
| VPVesuvius Penn Wampum/lawrence | Wampum | PA | — | ◇ UNVERIFIED |
| VUVesuvius USA | Crown Point | IN | — | ◇ UNVERIFIED |
| VUVesuvius USA Corporation | Dillon | SC | — | ◇ UNVERIFIED |
| WCWestern Clay Company- Aurora Bentonite Gypsum Milling Plant | Aurora | UT | — | ◇ UNVERIFIED |
| WCWestminster Ceramics L.l.c. | Bakersfield | CA | — | ◇ UNVERIFIED |
| WPWewoka Plant | Wewoka | OK | — | ◇ UNVERIFIED |
| WGWienerberger Group (general Shale) | Atlanta | GA | — | ◇ UNVERIFIED |
| WGWienerberger Group (general Shale) | Atlanta | GA | — | ◇ UNVERIFIED |
| WGWienerberger Group (general Shale) | Beltsville | MD | — | ◇ UNVERIFIED |
| WGWienerberger Group (general Shale) | Darlington | PA | — | ◇ UNVERIFIED |
| WEWizard Enterprise | Hawthorne | CA | — | ◇ UNVERIFIED |
| WEWizard Enterprise | Gardena | CA | — | ◇ UNVERIFIED |
| WPWonder Porcelain Group, LLC | Lebanon | TN | — | ◇ UNVERIFIED |
| WPWonder Porcelain Group, LLC Co-located Site: Nashville Ready Mix Mobile | Lebanon | TN | — | ◇ UNVERIFIED |
| WIWpw Industries INC | Streator | IL | — | ◇ UNVERIFIED |
| WRWyg Refractories | East Palestine | OH | — | ◇ UNVERIFIED |
| YBYadkin Brick Company INC | New London | NC | — | ◇ UNVERIFIED |
