Lumberock - Marine Grade Decking

Decking Installation

Please note that Lumberock Marine Grade Decking claims no liability or responsibility for the improper installation of our product. All installations are unique and it is the sole responsibility of the installer to determine specific requirements in regard to each application. We recommend that all designs be reviewed by a licensed architect, engineer or local building official before installation.

Installation Instructions and Technical Specifications

Please use the following links to learn about decking installation and other technical specifications for Lumberock.

To download a PDF of our Decking Installation Instructions click here.

Para descargar un PDF de nuestras instrucciones de instalación de terrazas, haga clic aquí

To visit our Technical Specifications section  click here.

Framing & Joist Span

The frame of a deck is its primary support structure, consisting of posts, beams and joists. Follow these deck framing guidelines before installing Lumberock®. All joists must be level and structurally sound for new and existing deck frames.

Use this table to determine the appropriate joist span for your residential or commercial project. Deck boards may be placed perpendicular to the joist or placed diagonally on the joist. Remember to install the Lumberock board with the wood grain pattern facing up.


To download a PDF of our Decking Installation Instructions click here. (Espanol)

Gapping & Thermal Expansion

Lumberock boards are gapped end-to-end, end-to-trim or end-to-house based on their location within your project. Proper gapping is necessary to accomodate a small amount of thermal expansion that is common to all plastic lumber materials. Lumberock boards do not need to be gapped side-by-side. The amount of expansion/contraction that occurs will depend on the length and temperature of the board at the time of installation. The most significant changes in the length of the board will occur when you are working in extreme temperatures. High altitudes will also increase these estimated expansion numbers.

You can expect that a 12-foot board installed at 60°F will expand 1/8″ on each end of the board. Therefore, an end-to-trim or end-to-house gap will be 1/8″ while two boards placed end-to-end will require a 1/4″ gap. Keep in mind that boards in direct sunlight will be warmer than boards stacked underneath. This chart is based on climates where the maximum temperature is 100°F. To account for end-to-end expansion, simple double these gap values.

Fastening Options

Lumberock can be installed using a face fastening system or a hidden fastening system. No pre-drilling is necessary to install our plastic lumber and several color-matching screw options are available. Two screws are needed per joist board. For joist spans measuring 16″ on-centers, 4.5 screws per square foot are needed. For joist spans of 24″ on-centers, 3 screws per square foot are needed. This figure does not include trim or railing screws.

For more information and to see a list of color-matching screw options click here.

Trim Board Installation

Install Lumberock 1×10 Trim Boards using two screws every 16″ or less. Composite screws (#7, #8 or #10) work best.