Trench Detail and Backfill Material                This will allow for a fast and efficient   away from the chamber. The rodding           opening cover and frame for installations
          The trench should be constructed 300mm             connection.                                point should be enclosed in a concrete       over 1200mm up to a maximum
          wider than the outside diameter of the                                                        surround to provide support and to ensure    of 3000mm invert depth.
                                                         G   Ensure all pipes and fittings are in the   that it does not become mislaid at
          pipe to be installed. Where the “as dug”                                                                                                   The chamber is installed
                                                             correct position.                          ground level.
          material is suitable, the bottom of the                                                                                                    on a suitable bed
          trenches may be trimmed to form a pipe         G   Insert pipe fully into the socket, then                                                 dependent on the
          bed. The material can also be used as a            withdraw pipe by a minimum of 12mm.                                                     quality of the trench
          sidefill and backfill. Imported granular           This will allow for expansion.                                                          and backfill materials.
          backfill materials such as pea shingle,                                                                                                    Backfilling is continued
          used in accordance with the                    Adaptors
                                                                                                                                                     up to approximately
          recommendations of BS5955 Part 6:              External rainwater Downpipes can be
                                                                                                        Inspection Chambers                          50mm of the finished
          1980 Appendix A, having a nominal              connected directly to a surface water
                                                                                                        Mini Access Chamber (MAC)                    ground level.
          particle size not exceeding 10mm, should       drain or, depending on the design, via a
                                                         gully trap to the underground drainage         A mini access chamber has a relatively       The frame and cover are
          be used as required up to and over the
                                                         system.                                        narrow riser shaft, and is used for          placed on a bed of concrete
          crown of the pipe. When this has been
                                                                                                        inspecting, clearing, and rodding a          around the top of the
          achieved the “as dug” material can be          The diameter of FloPlast’s 110mm PVC-
                                                                                                        drain line.                                  uppermost shaft, and adjusted
          replaced into the trench. Once 300mm of        U above and below ground drainage                                                           to the finished level.
          material has been replaced, mechanical         systems are the same and therefore a           The narrowness of the riser shaft permits
          compaction can commence.                                                                                                                   The frame is securely fixed
                                                         direct connection may be achieved              limited clearing and rodding to a
                                                                                                                                                     through the wall of the chamber at
          Testing                                        without the use of an adaptor. Where           maximum depth to invert of 600mm.
                                                                                                                                                     the set location points using self-
          Testing of all drainage installations should   rainwater pipes connect directly to a          Any unused side connections should be        tapping screws. The cover is then
          be carried out in accordance with the          drain, a suitable reducer will be required     sealed with a plain socket plug.             secured to the frame with the
          requirements of the appropriate                as follows:
                                                                                                        Should bends be required to change           captive screws. It is impossible for the
          approving authority, using either air or       G   SP96/D96 110mm x 68mm Rainwater                                                         cover to be removed without undoing
                                                                                                        direction, these should be sited at the
          water testing. References should be made           adaptor for Round downpipe.                                                             the screws.
                                                                                                        point of entry to the chamber.
          to current editions of Building Regulations                                                                                                Intermediate depths can be achieved by
          (Approved Document ‘H’) BS EN                  G   RDS2 used in conjunction with the above    Side branches of the chamber should not
                                                             adaptor for connection to 65mm Square                                                   cutting the riser at 60mm intervals; the
          752:1997 and BS EN 1610:1998.                                                                 be used to change direction of the main
                                                             Downpipe.                                                                               frame also has 55mm of telescopic
          Where drainage appears inside buildings                                                       flow, as a self-cleansing flow through the
          BS EN 12056 should also be consulted.          Connection to other materials such as          chamber cannot be guaranteed.
                                                                                                                                                     Any unused side connections should be
          Jointing                                       Cast Iron, Supersleeve and Hepsleeve, is       Intermediate depths can be achieved by       sealed with a plain socket plug.
          Pipe End Preparation                           achieved by the use of a range of rigid        cutting a riser at the indicated points.
                                                                                                                                                     Should bends be required to change
          When cutting pipes ensure that all ends        and flexible couplings and adaptors.           The frame and cover should also be           direction, these should be sited at the
          are chamfered and are free from swarf,         Access and Rodding Points                      adjusted to suit the level of the adjacent   point of entry to the chamber.
          grit and dirt.                                 Access is very important on all                ground and surrounded in a minimum of        Side branches of the chamber should not
          Ring Seal Joints                               installations for testing, inspection, and     50mm of concrete.                            be used to change the direction of the
                                                         removal of any blockage or debris.             Large Inspection Chamber                     main flow, as a self-cleansing flow
          The FloPlast Ring Seal Joint acts as both a
                                                         Rodding in both directions can be              incorporating Non Man Entry Restricted       through the chamber cannot be
          seal and expansion joint. The following
                                                         achieved by using a Mini Access                Access Cover & Frame                         guaranteed.
          sequence should be adhered to:
                                                         Chamber (MAC) or 450mm Large                                                                When installing the 160mm Large
          G   Check that all ring seal sockets are                                                      The large diameter of the riser shafts of
                                                         Inspection Chamber in conjunction with                                                      Inspection Chamber, it is necessary to use
              properly located in their recessed                                                        inspection chambers enables them to be
                                                         access fittings.                                                                            the base adaptor ring, this allows the use
              position.                                                                                 installed to a maximum depth to invert of
                                                         Rodding points are more usually used in        1200mm when used in conjunction with         of the 160mm Inspection Chamber Base,
          G   Ensure spigots and ring seal sockets       storm water drainage systems where the         a 450mm opening cover and frame. The         and the existing riser and lid products
              are dry, clean and free from grit          rodding point is located at the head of        chamber complies with Approved               developed for the 110mm Inspection
              and dirt.                                  the drain run connection to a chamber,         Document H of the Building Regulations       Chamber, please refer to the items for the
                                                         and being no further than 22 metres            2000 by using the 350mm reduced              FloPlast 160mm range on page 9.
          G   Lubricate all ring seal fittings.

10                                                                                                                                                  11

To top