| SEWAGE PIPES | BLÜCHER UK LTD |
| HEPWORTH CLAY & TERRACOTTA |
| HOWARTH TIMBER GROUP |
| NAYLOR |
| OSMA |
| PAM BUILDING |
| POLYPIPE BUILDING PRODUCTS |
| SEWAGE PIPES Adoptable Systems | NAYLOR |
| SEWAGE PIPES Backflow Valves | ACO TECHNOLOGIES PLC - BUILDING DRAINAGE |
| ALTHON LTD |
| ALUMASC WATER MANAGEMENT SOLUTIONS |
| FERNCO LTD |
| S1E LIMITED |
| WAVIN |
| SEWAGE PIPES BS 4660:2000 | OSMA |
| SEWAGE PIPES BS 5481 | OSMA |
| POLYPIPE BUILDING PRODUCTS |
| SEWAGE PIPES BS EN 13476 | OSMA |
| SEWAGE PIPES BS EN 13598 Parts 1 and 2 | OSMA |
| SEWAGE PIPES BS EN 1401:1998 Part 1 | OSMA |
| SEWAGE PIPES BS EN 1401:1998 Part 1 Kitemarked | OSMA |
| SEWAGE PIPES BS EN 295-1:2013 | HEPWORTH CLAY & TERRACOTTA |
| SEWAGE PIPES PVC-u | HOWARTH TIMBER GROUP |
| OSMA |
| SEWAGE PIPES PVC-u AGREMENT CERTIFICATE HOLDERS | OSMA |
| SEWAGE PIPES PVC-u BS 5481 | OSMA |
| POLYPIPE BUILDING PRODUCTS |
| SEWAGE PIPES PVC-u Structured Twinwall Pipes | OSMA |
| SEWAGE PIPES PVC-u WIS 4-35-01 CERTIFICATE | OSMA |
| SEWAGE PIPES Stainless Steel | BLÜCHER UK LTD |
| SEWAGE PIPES Vitrified Clay BS EN 295-1: 2013 Kitemarked CE Marked | HEPWORTH CLAY & TERRACOTTA |
