Importance of sound installation
While decks are a popular feature in many homes, the construction and safety of decks is a huge concern within the local building industry. Improper deck installations has resulted in a growing number of deck failures and related injuries. While decks are required to meet certain code standards and load capacities. It is estimated that only half of decks installed are compliant, leaving a number of decks that need to be rebuilt or retrofitted at a later stage to prevent collapse and injury.
How will I know how to install Envirodeck products correctly?
Envirodeck has compiled a fully comprehensive Installation Manual for both the LifeCycle Range and the Urban Range of decking and accessories. It is vitally important to read these documents prior to the building commences on the deck. If the guidelines within the Installation Manual documents are not adhered to; it shall void any and all warranty, and Envirodeck will not be responsible or accountable for the performance of Envirodeck products. This Frequently Asked Questions document is not an installation guideline, merely a quick answer reference document.
Do decks really need to meet code requirements?
Decks look relatively simple to build, and many people do not realise that decks are structures that need to be designed to adequately resist certain stresses. Like a house, or any other building, a deck must be designed to support the weight of the people and objects placed on them, as well as the lateral and uplift loads that can result on them such as wind.
What basic guidelines can I use for substructure preparation?
If you are intending to use Envirodeck profiles on an existing joist structure, check to make sure that all the joists are level, structurally sound and have no existing nails/screws protruding. Proper joist spacing is required for good installation - refer to the specific product installation manual for detailed information on this point.
What tools are required and does the product cut like wood?
Envirodeck products are installed using the same tools that you would use to install any form of wood decking. The product cuts very neatly using a circular saw. Refer to the installation manual for a full list of tools required for installation.
How do I manage expansion and contraction?
All decking material, whether wood, composite decking or PVC decking, undergoes some degree of linear expansion along with any changes in temperature. To ensure the same look throughout the deck, ensure that all the gaps are in a step/staggered format across the various joists so that your eye does not catch all the joist gaps in a straight line. Ensure that all the boards are pinned in the correct places to ensure movement of the boards in the correct direction. Refer to the Envirodeck installation guideline for a graphical illustration of this process. Make sure that all the boards are laid out in the sun prior to installation so that all the boards are the same temperature before cutting and fitting them to avoid expansion and contraction after installation, otherwise your gaps will vary across the deck.
How do I start and finish the deck?
The first board that is laid on the deck closest to the house or edge of a permanent structure of the deck is called the starter board and is installed with the Envirodeck Starter Clip. Each clip is unique to its own Envirodeck Product Range. Once the first board is secured with the starter clips, then the concealed clipping system can be placed along the outer edge of the starter board and secured to the joist. Continue placing consecutive boards and clips until the deck is complete.
When finishing the deck, the last board should be treated in the same manner as the Starter board, secured to the rim joist with a finishing clip. The width of the finishing board must be reduced to finish flush with the rim joist; or if working with the LifeCycle Range, a maximum overhang of 40cm can be allowed, supported by the finishing clip. The ends of the board should be given a slight overhang to be trimmed straight and neat once the deck is completed. A maximum end of board overhang is 50mm.
How do I fasten the boards to the joists?
The concealed clip system and stainless steel screws are used to fasten the deck to the substructure. Our unique concealed clip can be used with the recommended substructure material mentioned above and is specifically designed to fit the grooved side profile of the board. The clip is engineered to manage both linear and width expansion across the deck. An Envirodeck screw longer than 50mm with a course thread can be used with the clip, but the head of the screw is an important aesthetic feature of the deck and should be coloured to match the clip.
Do not nail down through the top of the boards as they will crack and split due to incorrect installation procedure. This will void any and all Envirodeck warranty. As there are no wood grain or chips in composite materials, pre-drilling with our unique countersinking drill bit is recommended for the screws.
Why do the gaps in my deck change in width?
Composite products do not have a wood grain and therefore expand and contract along the linear length of the decking board with minimal expansion across the width of the profile. The clip is manufactured with "wings" to absorb the expansion and contraction across the width of the deck. The longer the length of the board, the greater the potential for change in the length, induced by temperature variances. A critical factor in calculating the correct gapping width is the temperature of the boards when being cut for installation. A hot board lying in the sun will eventually contract after installation therefore opening the gap and a cool board will eventually expand as the temperature of the board increases, closing the gap. All boards should be installed at the same temperature otherwise all the gaps will be inconsistent throughout the deck.
The best guide for ensuring the correct gapping for various lengths being installed across the deck is practical experience in working with the material. For example: a shorter board, around 1m in length does not need a 10mm gap but rather a 1mm gap on joist gaps, as the expansion coefficient of that individual board does not suffice a 10mm gap. If the board is installed in hot conditions, no gap is required and when the board contracts, the gap will be around 1mm, therefore personal intuition and experience is key. Careful calculation of the expansion and contraction of the boards is required for the butt joints. Gapping around rail posts, edges of decks and cladding requires careful consideration as well. Temperatures can significantly increase or decrease the gap width.
Envirodeck is not responsible for any change of joist gaps after installation whatsoever.
How do I use the clips where gaps are required in the decking?
Our concealed clip system makes installation easier and faster. The concealed clip system reduces the number of screws required per square metre to install the decking than wooden decks that require plugging. A joist should support the end of every decking board otherwise the board will flex under foot. Each board needs to be anchored individually over a double joist where there is a butting of boards in the decking. The concealed clip should be loosely positioned along the board on every joist; before sliding the next board into position. Remember to set the drilling machine on a low torque to prevent over tightening of the clip. Make sure that all the clips are evenly spaced across the various joists and the boards are perfectly straight before fixing them.
What are the reasons for using the concealed clip system?
There are a number of benefits for using the concealed clip system:
• Improved aesthetic of the deck, as the clip and screw are practically invisible once the deck is installed.
• Reduces the number of screws required to install the deck.
• Provides a uniform gap between the decking boards, aiding airflow and makes installation easy
• The less screws used to install the deck reduces the cost of installing the deck.
• Provides a safe, smooth and barefoot-friendly surface - no sharp objects that can cause injury
• Doesn’t disrupt the clean, smooth lines of the deck by having unsightly screws through the surface.
Most importantly, the concealed clip system provides the best fastening option as the clip conveniently manages the expansion and contraction of the deck independently to the substructure it is installed on. The deck is therefore "free floating" as the clips allow the boards to heat up and cool down without being subjected to alternative expansion and contraction by the substructure it is installed upon. Different substructures will expand and contract differently, and the clip manages this process by eliminating the build-up of pressure that occurs when decks are screwed directly into the joists. This independent movement is a critical feature when installing composite products onto any substructure.
Is Envirodeck liable for the installation methods and performance of all products sold?
No. All installations should be in accordance with our Envirodeck installation manual, specific to the product range purchased; and local building codes. Envirodeck claims no liability or responsibility for the improper installation of its products whatsoever including but not limited to improper gapping specific to each Envirodeck profile. Since all installations are unique, it is the sole responsibility of the installer to determine specific requirements in regards to each decking application. Envirodeck recommends that all designs should be reviewed by an architect, engineer, approved decking installer or local Envirodeck representative prior to any installation.
When do I use the screws and the countersinking drill bit?
Envirodeck Ranges are installed with the integrated concealed clip system and do not require the use of colour coated screws but they can be a personal preference. Screws are not used through the top of the board except for pinning the starter and end board, and matching the fascia board/ corner strip/ cladding, etc. to the decking boards. This tool minimises the risks of splitting the fascia board that occurs when screwing directly into the fascia board. The colour coated screws should be installed with a very low torque setting on the drilling machine to avoid over driving the screw.
What options are available to finish off a deck?
There are a variety of finishes available for completing the edges of the deck for a clean, professional finish. Refer to our product catalogue or contact Envirodeck for full list of finishes available depending on personal preference, decking range or application specific requirements.
What applications are suited to the pre-drilling and countersinking tool?
Even when a material is considered soft enough to not require pre-drilling, the waste material from the screw hole can form a small mound that is unsightly, a problem that can be avoided by pre-drilling. Regardless of the type of decking wood decking used, some splintering around the screw head will naturally occur if holes are not pre-drilled and countersink. Not only is splintering unsightly, it can be a nuisance to bare feet. For a clean looking, safe deck always pre-drill and countersink screws