Hardwood Decking Installation Guide

Important Facts

Our harwood decking products are kiln dried to 15-18% moisture content. They are different, in many respects, from cedar, fir, pressure treated lumber, or synthetic decking products.

This timber will not shrink appreciably after installation. It will expand slightly from side to side when it becomes wet.

Proper ventilation and airflow beneath the deck must be incorporated into your design to avoid problems that may occur when wood naturally expands and contracts as it assume and expels moisture.


Site Selection and Preparation; Ventilation

Design your deck to allow the deck boards to dry evenly from beneath and above the surface of the deck. Uneven drying of the tops and bottoms of deck boards during rapid periods of climate change in the main cause of cupping.

Your deck should be raised a minimum of 18" off the ground.

Decks that are less than 3 feet off the ground should be constructed with 4" deck boards.

Allow air to flow freely beneath the deck. Use lattice, or other skirting that permits air to flow beneath, and cross-ventilate the underside of the deck.

Provide sufficient drainage beneath the deck. Standing water can be absorbed into the bottom surfaces of deck boards.

Properly gap boards, side to side, to allow air to flow freely out the top of the deck.


Spacing Deck Boards

Kiln-dried or air dried hardwoods will swell slightly from side to side when they become wet.

For proper spacing when applying deck boards:

Space 5/4x6 deck boards 1/4" apart from side to side.

Space 5/4x4 and 1x4 deck boards 3/16" apart from side to side.

Butt boards tightly end to end.


Sawing, Fastening, Nailing

The interlocking grain of our hardwood decking holds fasteners exceptionally well.

Stainless fasteners can be a significant part of the cost of your project; however, do not be tempted to economize when making your decision on which type of fastener to use. Dwyer Hardwoods recommends type 316 stainless steel screws and nail for coastal applications. Type 316 is the only grade stainless on the market that contains molybdenum for the highest corrosion resistance available.

It is important to note that Blue Star will not stand behind any of its products that have been anchored with a blind fastening system such as Eb-Ty.

Stainless screws or nails, made specifically for decking, are the best fasteners for these products. Stainless screws are convenient, while providing a clean, secure, long lasting performance. They are also less likely than nails to cause splitting.

Blue Star Meranti does not contain tannins. It will not react with metal to create black stain. Galvanized fasteners may eventually rust and stain the lumber. Coated steel screws often lose their coating during installation, and may eventually rust and cause staining.

Fasteners should penetrate approximately 1-1/2" into the substructure of the deck. Sink them at an angle of about 10 degrees and away from the immediate edge of the board.

Drive screws and nails 3/4" from the edges and ends of the boards. Use 3 fasteners across the face of 6" boards; 2 for 4" boards. This configuration, along with proper board spacing and adequate ventilation, is the best assurance of a flat, smooth deck.

When fastening the ends of the boards, consider drilling pilot holes to minimize the potential for small splits.

If air-driven fasteners cause splitting, adjust your air pressure.

There is no need to "crown" the grain of these boards; either side may face up or down.

Examine both faces for appearance, and select the face most pleasing to you as the top of the deck board.



A proper coating of top quality finish will help your deck boards acclimate without disturbance. We suggest an initial application on all surfaces of the boards, including the ends.

There are dozens of brands of available finishes, many of which work well. Most are a combination of natural or synthetic oil and turpentine ( or some other penetrating agent). Deck finishes do not "seal" lumber. Rather, they penetrate the wood fiber and help slow the absorption and expulsion of moisture, thereby diminishing the shock that wood fiber may experience during a period of rapid drying. Finishes also help set and retain the natural color of the timber.

Should you wish to maintain the original color of the timber, re-treat the deck according to need. Prior to re-treatment, clean the deck and allow the timber to dry before applying the new coat.

After the initial application of finish, you may elect to let your deck turn silver. If this is your choice, we still suggest the initial application of finish be performed.

Use a top quality finish for top quality results.

We have experienced excellent results with finishes that contain mildewcides, fungicides, and U.V. inhibitors. We suggest the finish contain a slight pigment to help diminish discoloration or fading from sunlight - especially for decks that face directly into the afternoon sun.


Job Site Preparation

Dwyer Hardwoods decking products are all delivered to you clean and dry.

Keep the lumber clean and dry prior to use. Stack lumber flat and off the ground until ready for use. Do not leave individual boards lying loose, exposed to the weather.

Once you apply your initial coat of finish, fasten the deck boards without much delay.