3.1 Ground Preparation
The excavation shall be carried out in two operations. Firstly the court
area shall be excavated to formation level, which shall fall 75mm (3")
over the length of the court. The formation shall be rolled to achieve
a firm surface. All soft spots shall be removed and backfilled using suitable
material, prior to the completion of the rolling.
Subsequently the footings to the court boards shall be carefully excavated.
Again all soft spots shall be backfilled using suitable material.
Following the placing of the concrete to the footings, the formation
level shall again be rolled to make good any loose areas.
3.2 Court Construction
3.2.1 Concrete Footings
The concrete footings to the boards shall be carefully placed and
compacted to the dimensions shown on the drawings.
Grade RC35 concrete shall be used.
Accurately located pockets shall be formed in the upper section of
the footings to receive the board fixings. The top surface of the toe
of the footing shall be sloped to suit the formation level to the drainage
The top surface of the upper section of the footings shall have a steel
float finish and shall be constructed to close tolerances:
100 mm (4") diameter perforated plastic drainage pipes to BS 4962,
shall be laid along the length of the court on the prepared formation
level. This should ensure a 75mm (3") fall in the pipes. Pockets
shall be excavated in the formation to accommodate pipe joints so that
full bearing support is provided to the whole length of the pipe barrel.
The ends of plastic pipes with spigots and sockets or sleeves shall
be dry jointed.
The pipes shall be connected into a surface water drainage system off-court.
Ideally this drainage system shall discharge to suitable ditches or
watercourses. If the system discharges to a soakaway, then utmost care
shall be taken to ensure that the soakaway is designed to accommodate
rainwater discharge from the court during storm conditions.
3.2.3 Drainage Layer (Natural Gravel or Crushed Rock - 225mm (9")
A 225mm (9'') foundation layer of free draining natural gravel or
crushed rock, other than argillaceous rock, shall be provided to the
court. It shall be free from earth, clay, organic matter and other impurities,
and be hard, dense and non-plastic when tested in accordance with BS
1377, and graded as follows:
100% passing the 63mm (2½") sieve
85-100% passing the 37.5mm (1½") sieve
0-25% passing the 20mm (¾") sieve
0-5% passing the 10mm (3/8") sieve
The crushed rock shall be compacted using a 225kg (500lb) non-vibratory
3.2.4 Gravel Course (Crushed Aggregate - 75mm (3") Layer)
The existing crushed stone shall be choked with a 75mm (3")
layer of 20mm (¾") gravel. The 20mm (¾") gravel
shall be natural gravel or crushed rock, other than argillaceous rock,
be free from earth, clay, organic matter and other impurities, and be
hard, dense and non-plastic when tested in accordance with BS 1377,
and graded as follows:-
100% passing the 28mm (1") sieve
30-55% passing the 5mm (Imperial No. 4) sieve
0-15% (based on the fraction passing the 5mm sieve) passing the 75um
(Imperial No. 200) sieve except that the gravel shall be washed.
Water shall be added to the crushed aggregate prior to performing the
grading operation. The 20mm (¾") gravel course shall be
maintained in the moist condition until it is covered.
The crushed aggregate shall be rolled with a vibratory compactor to
a density as determined by ASSHTO T 99 (Proctor Density).
3.2.5 Clay Foundation Course (Place 100mm (4") to yield 75
mm (3") Compacted Layer
The clay foundation material shall consist of Stiff Clay with 100%
passing a 75m (Imperial No. 200) sieve and with a Plasticity Index of
31 or more. The clay shall be pulverised to pass through a 13mm (½")
sieve. Roller compacting shall be delayed until the surface course is
3.2.6 Installing Court Boards
Accuracy in installing the court boards to the correct position
and level is vital.
(a) Support Angles
The 76 x 76 x 6mm (3" x 3" x ¼") aluminium
support angles must be installed vertically and to an accuracy of
+ 6mm relative to the board. The Contractor must provide a purpose
made jig to effect this operation. Once located the angles shall be
grouted in place using an epoxy non-shrink grout.
All metal angles, plates, strips, bolts, screws and washers shall
be manufactured from non-ferrous metal.
(b) Court Boards
The court boards forming the perimeter of the court shall be made
of glue laminated (glulam) timber beams manufactured in accordance
with BS 4169.
Glulam beams are factory made from four or more separate laminations
of timber, arranged parallel to the longitudinal axis of the timber,
and glued together. The laminations have a maximum thickness of 45mm,
and may be either softwood or hardwood from a renewable source.
The manufacturer shall provide beams suitable for exterior use, with
the adhesive in accordance with Table 1 of BS 4169 for exposure category
Exterior High Hazard. The surface finish shall be fully planed with
knot holes, fissures, voids and similar defects filled or made good
with glued inserts and finally all sanded. The top corners of the
boards shall be rounded off with sandpaper.
The inside face of the boards shall be permanently etched for their
full height at the positions of the court markings.
Organic solvent preservative to BS 5268: Part 5 shall be used for
treating the beams during manufacture. Bitumastic paint shall be applied
to the surfaces of the boards to be in contact with the ground and
is to finish 100mm below the top of the board on its rear face.
(c) Fixing Court Boards
The board shall be laid in position, and adjusted for level with
shims. When this is acceptable, pilot holes for the fixings shall
be drilled using the angles as a template. Final fixing of the boards
shall be achieved by screwing 75mm (3'') No. 12 stainless steel roundhead
screws through the angles and into the pilot holes, and using appropriate
thicknesses of shims to pack to the correct position. Countersunk
screws shall not be used.
The unthreaded shank diameter of a No 12 screw is nominally 5.5mm.
The preferred joints to be used for longitudinal connections are
hidden mortise and tenon joints, and those for corner connections
are hidden finger joints, as shown on drawing No. CCB 008. Alternative
joints may be proposed by the Contractor, but full details of the
proposal must be agreed by the Engineer prior to the ordering of the
The joints shall be glued using an appropriate exterior grade adhesive,
and pegged with hardwood dowels.
(d) Finishing Court Boards
To finish the boards and provide a tidy top edge to the bitumastic
paint, an aluminium edge strip 50x 6mm (2'' x ¼'') shall be
screwed to the rear of the boards with 25mm (1'') No. 6 stainless
steel roundhead screws at 300mm (12'') centres. Its top edge shall
finish 100mm (4") below the top of the board
The unthreaded shank diameter of a No 6 screw is nominally 3.5mm.
No coats of a good quality timber stain shall be applied to the exposed
surfaces of the board prior to laying the court surfacing, with a
final coat applied subsequent to the surfacing. Any necessary cleaning
of the boards shall occur prior to the application of the final coat.
3.2.7 Clay Surface Course (Place 30mm (1¼") HAR-TRU
Surfacing to yield 25mm (1") Compacted Layer
Har-Tru surfacing material shall wherever possible be obtained from
the HAR-TRU Corporation. (See clause 6 for details)
This course shall consist of a clay-sand-salt mixture. The clay shall
meet the requirements of the foundation clay (Item 3.2.5 above), except
that the surface clay shall be pulverised to pass through a 6.70mm (¼")
sieve. The sand shall be clean sand with 100% passing a 3.35mm (1/8")
screen and no more than 0-5% passing a 1.70mm (Imperial No. 10) sieve.
The sand shall be free of organics. The salt shall be common fine grained
white salt. The surface course shall consist of the following mix:
A 225kg (500 pound) smooth roller (lawn type) compactor shall be used
to compact the clay courses. The maximum deviation from level, both
transversely and longitudinally, shall be 6mm (¼") in 3m
(10'), which shall be checked using a 3m straight edge. After rolling
to a smooth surface, spray with water to obtain standing water film,
then roll again until the water disappears.