Decking & Sub-Frame Installation Guide

Elegro Plastic Decking Important Image

• ELEGRODECK can be cut and drilled in the same way as timber, however care should be taken to eliminate drill/saw-slip as this can mark the surface of the product.

• It is recommended that the decking boards are cut and installed at the same temperature.

• While the decking range is non-toxic and safe, adequate PPE must be worn during installation of ELEGRODECK products.


ELEGRODECK may be installed on a sub-frame made of wood, recycled plastic or aluminium joists. In this installation manual we will be using 95mm x 50mm plastic joists, however joists of differing dimensions can be used.

Joist strength calculations should be carried out to ensure the sub-frame has the capability to bear the weight of both the ELEGRODECK plastic decking boards and the load placed on top (hot-tubs, furniture etc) 1m = 3.5kg and 1m³•2 = 23kg

The ground below the decking must be even, stable and well consolidated to avoid sagging, uneven loading and subsidence. If you are in any doubt as to the suitability of the sub-grade build-up, it is recommended you employ the services of a qualified groundworker or civil engineer.

Joist Spacing
The recommended distance between the sub-frame joists is 375mm, measured from the centres of the beams. The maximum distance between joists should not exceed 400mm centres. Joists should be at least 50mm in width.

Installation Fig A

Installing the Deck Boards
An edge clip should be screwed to one end of each joist. Take care to ensure that the clips are aligned with each other and that they do not protrude past the edge of the joist as this will impede installation of fascia boards.

Installing Plastic Decking Joists for Elegrodeck

Pedestal Supports
If using the adjustable pedestal or cradle supports, these should be installed beneath the joists at intervals of no greater than one metre apart. Care shoud be taken to ensure the clips hold the joist in place and that all provide a level platform for the decking board. These pedestals can be adjusted in-situ for your convenience.

ELEGRODECK Sub-Frame Image

Installing First Board
The first decking board should be cut to the required width and installed onto the joists, ensuring that the edge clips sit snugly into the groove on the outer edge of the board.

Installing First Elegro Deck Board Fig

Installing Subsequent Boards
Once the initial decking board is installed and pushed tightly to the edge clip, install a decking clip on each of the joists. Each joist requires no more than one decking clip, which is installed with a single screw. The decking clips allow for longitudinal movement and expansion of the decking boards.

Installing Subsequent Decking Boards Fig

Material Expansion
ELEGRODECK boards are made from a recycled plastic material and as such can alter in length with changes in temperature. When building the decking, it is necessary to leave an expansion gap at one end (B). A temperature change of 1°C changes the longitudinal dimension by 0.0069mm per 1m.

Expansion Fig for Elegro synthetic wood decking

Material Expansion
One end of the decking should be attached to the joists using two screw, inserted diagonally to ensure expansion occurs in only one direction. In some installations it may be possible to allow expansion at both ends, using a single screw in the middle of the deck board Option D. There are FOUR options:

Plastic Decking Expansion Figure A

Option A

Recycled Plastic Decking Expansion Fig B

Option B

Elegro Deck Expansion Fig C

Option C

Elegro Decking Board Expansion Fig D

Option D

Extending Decking Boards
If the decking area requires a length of decking board which is longer than the 3m standard board length, then boards can be joined together using a stainless steel plate. Using the stainless steel plate and no less than 8 screws, attach the plate to the underside of the decking board, within the centre channel as shown.

Extending Recycled Plastic Decking Boards

Supporting the Joining Plate
The stainless steel joining plate must be supported by a sub-frame joist to prevent the decking board construction from sagging at the join. The joining plate must be in the middle of the joist and a fixing clip must be installed, central to the join with the clip spanning both boards.

Extending Plastic Decking Boards with Plates

Installing Fascia Boards
Fascia boards are an optional part of the ELEGRODECK installation, but when installed completely disguise the sub-frame construction and complete the installation to a professional, highly attractive finish.
The ends of the fascia boards which are going to be installed need to be drilled with pilot holes for the screws, which are oversized by 2mm to allow for expansion. The screw heads must be large enough to cover the additional 2mm. The fascia boards should be attached to the sub-frame at intervals of no more than 500mm.

Installation Elegro Deck Fascia Boards

Installing Fascia Boards
Pilot holes only need to be drilled for the screws at each end of the fascia and not for the fixings in the middle of the board. The screws should be installed evenly and with a sufficient, consistent space between them.

Installing Elegrodeck Plastic Decking Fascia Boards

Fascia Board Corners
The corners of the fascia boards should be mitre cut at 45° (or other mitre angle according to the requirement of the installation). This enables the fascia boards to be installed with clean, sharp corners and provides the best visual finish.

Creating Elegro Decking Board Fascia Mitre

Fascia Board Expansion
Fascia boards should be installed with a 5mm gap (A) between each vertical joining point to allow for expansion and contraction under differing weather conditions. Joist height will determine how many fascia boards can be installed. The standard depth of a fascia board is 95mm.

Recycled Plastic Decking Fascia Board Expansion