Working with Recycled Mixed Plastic Lumber

Recycled Plastic Lumber Group of Profiles

DRILLING

All fixing holes should be pre-drilled with an HSS or wood bit prior to screwing.

A low drilling speed is recommended.

SAWING

Recycled plastic can be sawn using a handsaw, circular saw or chop saw (including cross-cut mitre saws).

A slow cutting speed with a medium tooth blade is best, for example a 305mm 60 tooth TCT blade.

If a slow cutting speed can not be achieved it will be necessary to reduce the number of teeth on the blade, for example a 305mm 40 tooth TCT blade.

In all cases when working with recycled plastic it is recommended to keep operating speeds low in order to prevent material from melting on the surface of your implement

A bit of WD40 on the blade can also help.

RAIL EXPANSION AND CONTRACTION

  • Plastic is subject to thermal linear expansion and contraction, hence it’s importance to make allowances within the design of Kedel fencing installation.
  • Expansion Gap – A gap should be left where the rails butt up.
  • Allow for maximum expansion with consideration to temperature at the time of installation. The lower the temperature at the time of installation, the larger the maximum expansion will be. The higher the temperature at the time of installation, the smaller the maximum expansion will be.

Maximum expansion occurring per running meter per installation temperature:

Expansion Table Maximum expansion (contraction) per running metre:
Temperature 0°C 5°C 10°C 15°C 20°C 25°C 30°C 35°C 40°C
Max. Expansion +7mm +6.5mm +6mm +5.5mm +5mm +4.5mm +4mm +3.5mm +3mm
Max. Contraction (-2mm) (-2.5mm) (-3mm) (-3.5mm) (-4mm) (-4.5mm) (-5mm) (-5.5mm) (-6mm)

Minimum temperature in Western Europe = -20°C; maximum temperature in the sun of e.g. black boards = 50°C. Assuming that the installation is normally done at a temperature between 10°C to 20°C, the maximum temperature difference will be in the region of +40°C (expansion) and in the region -40°C (contraction). This demonstrates the importance of taking into account the process of expansion/contraction.