Engineered Plastic Systems, LLC
Deck Installation Guide

1. Structural Ability

EPS lumber is not recommended for structural applications and should not be used as a frame on a deck, except when the deck rests on the ground. If you need structural lumber then use our fiberglass reinforced board

 2. Joist Spacing

Residential use will require the following spacing: 

Commercial Use requires: 

3. Expansion/Contraction

Spacing between boards will remain constant, so use a pencil or large nail to determine spacing. The board does expand and contract along its length.  A 10’ length will expand and contract, over a 100 degree swing in temperature, up to .54”. So each end would move .27" from the coldest to the hottest day.  Also, lighter colors do not heat up as much in sunlight and are therefore preferable when installing a deck in a very sunny location. You really need to measure the temperature of the board and not ambient temperature. Just because it is 70 degrees outside doesn't mean the board is 70 degrees. If it is dark and in the sun it might be 100.

If you are going for a seamless look and must use a board over 12', we recommend you use a plastic biscuit floating system. This is where we groove both sides of the board and allow the longer boards to move freely with the use of plastic biscuits. Call for more info.

  4. Fastening

To withstand the expansion and contraction as well as to maintain a long lasting, beautiful looking deck, stainless steel deck screws should be used, preferably #10 x 2 ½ or 3” long, square drive stainless steel deck screws.  For ease of installation,  screws should be pre-drilled and counter-sunk. You may opt to not pre-drill and be aware that you may experience pigtails of material as well as broken screws, from time to time, due to friction heat.

For a seamless look, we recommend the use of Counter-Snap screws up to a 12' board.  For more information, click the logo . Download our flyer demonstrating the Counter-Snap screws (pdf). Longer lengths should use a plastic biscuit system.

5. Butt Joints

When butting against any wall, fixed surface or other boards (if necessary), they should be securely fastened to the nailer or double joist with a gap allowing for expansion.  The size of gap should be determined based on weather conditions at the time of installation – the closer the temperature is to the usual high temperature for the year, the smaller the gap.  (See chart). In the event that joints are required, a double joist underneath the butt joint can be used.  Boards should be securely fastened with a row of screws on each side of the joint.

  6. Rip Cutting

Two cuts must be taken in the event that a board must be ripped down in width.  This is due to the difference in tension between the outer “skin” of the board and board’s center.  For example, if a 4” board is needed, ¾” should be ripped off of both sides of a 5-1/2” board.

7. Anti-Slip Resistance

Make sure to inspect the lumber and turn the wood grain pattern upwards for maximum slip resistance.