Building Materials

5/4 and Composite Decking

Why are so many more Dek-Block® piers required when using 5/4 treated or composite decking?

5/4"x6" treated, cedar, redwood and composite decking do not have the same degree of span strength that a 2"x6" treated or cedar board does. 5/4"x6" decking boards are thinner and typically have rounded edges, which decreases the overall strength of the board. For this reason, a narrower span of 16 inches on center is required between support boards. Thus the great number of blocks and support boards for the project.

Always check with your composite board manufacturer for the span support required for the board type you'll be using. Some composite boards can only span 12 inches on center, while some can span 20 inches. These spans are very uncommon.

What else should I know about using Composite Decking?

First and foremost, there is no such thing as "maintenance-free" decking.
Even composite decking requires some degree of upkeep - it's 50% wood. Check with the manufacturer regarding the specific care for your product.

Composite decking needs to have holes pre-drilled for the deck screws.

Special screws are needed for composite decking to reduce "mushrooming." An excellent screw for composite decking is manufactured by GRK Fasteners. Click Here for more information on GRK Composite Decking Screws.

Composite decking must be spaced according to the manufacture's recommendation. Typically 1/8 to 1/4 of an inch. You may also consider using a few deck spacer tools.

Support Boards

Can I use 2"x8" or 2"x10" support boards?

Yes, 2"x8" and 2"x10" support boards are fine to use with the Floating Foundation Deck System. However, using 2"x8" or 2"x10" support boards DOES NOT reduce the number of Dek-Block® piers required for each support board, or the spacing between support boards. The minimum number of Dek-Block® piers is based on the distribution of weight on the ground which does not change by the thickness of the support board.

Can I use 2"x4" support boards?

We do not recommend building an entire deck using 2"x4" support boards. 2"x4" supports can be used in some situations where height is critical, but only for less than 20% of the entire support structure. For example: If the entire deck has 10 support boards, no more than two should be 2"x4"'s. If 2"x4" lumber is needed, position a Dek-Block® pier every 30" along the support board.

What is Toe-screwing? 

Toe-screwing or toe-nailing is when you drive a screw in at an angle from the SIDE of one board into the top or face of another. For example: When attaching the support board to the 4"x4" post, drive a screw at an angle from the support board into the top of the 4"x4" post.

Is Toe-screwing really strong enough to support the weight of the deck?

Yes. Unlike conventional deck construction, which only has a few connection points, the Floating Foundation Deck System has a large number of connection points. The lateral forces of the deck are spread out evenly over this large number of points, thus elevating the need for rigid connections at each post. If you feel more comfortable having additional support, you can consider using a metal bracket.

Should I use joist hangers on the end boards?

No. Joist hangers are used to transfer a load from the joist to a ledger board or beam on conventional deck construction. In the Floating Foundation Deck System, each support board is independently supported. The end board is not load bearing at all. It simply joins and stabilizes the support boards.

Do I need to install the end board if it's next to the house and wont be seen?

Even though the end board is not load bearing, it does join and stabilize the support boards. Therefore, It is required for the system to function properly.

Surface Boards

Do I need to leave a space/gap between the surface boards?

Pressure treated lumber (Within 2 weeks of purchase or wet)
Place the boards directly next to each other (edges touching). The moisture in the lumber will dry within a few weeks and leave a small gap between the boards.

Pressure treated lumber (Older than 2 weeks or dry), Cedar or Redwood
Use either a nail, a screw or a deck spacer tool to create a small gap (1/8"-1/4") between the boards.

Composite Decking
Use either a nail, a screw or a deck spacer tool to create a small gap (1/8"-1/4") between the boards. Check with the manufacturer before starting for spacing recommendations. Some products require specialized spacing gaps.

Is there a reason why the surface boards run perpendicular to the house?

Not really. There is no structural difference between the deck plans that have the surface boards running parallel or perpendicular to the house.

When the surface boards run perpendicular to the house, there are a few advantages:

1. The deck is slightly easier to build.
2. Only one row of Dek-Block® piers are exposed from the edge of the deck.
3. If the deck is wider than 16ft. splicing of the surface boards may not be needed.

How do I get plans with the surface boards running the opposite direction?

In the plans section of the website, reverse the dimensions. Instead of 12ft. wide by 16ft. deep, enter 16ft. wide by 12ft. deep.

How long should I wait before staining / sealing my deck boards?

Timing for staining / sealing your deck is dependent upon the type of decking material you have, how wet (or green) it is, your local weather conditions (humidity, etc), and the product being used. Always follow the manufacturer's recommendations.

Typically, there are two different types of sealer:
1. A sealer which applies a protective film to the surface of the lumber. The lumber should be dried for 1-2 seasons before applying. Once the lumber has dried, the sealer will protect against moisture entering the wood, but not existing. If you apply this type of sealer before the lumber has dried, small cracks will form as water escapes. This creates openings for water to return. Thompson's Water Sealer would be a common brand of this type of sealer.
2. A sealer which soaks into the material and works similar to a GoreTex® material. It can be applied immediately to virtually any material. It soaks into the wood and allows the wood to breathe, while releasing interior moisture and preventing additional moisture from seeping in. Cabot would be a common brand of this type of sealer.

Dek-Block® Piers

Why are there so many Dek-Block® piers?

The Floating Foundation Deck System is a "Weight Distribution System." This means that the loads of the deck are being evenly dispersed across the entire ground area upon which the deck rests (as opposed to conventional decks that concentrates weight to only few discrete points). We do not recommend concentrating the loads on the Dek-Block® piers.

Can I do anything to reduce the number of Dek-Block® piers?

No. The number of Dek-Block® piers in all of our plans ARE the MINIMUM required to meet engineering and building code requirements. We do not recommend reducing the number of Dek-Block® piers shown in the plans or in our spacing requirements.

Is my 4"x4" post fitting too loose or tight in the Dek-Block® pier?

No. The Dek-Block® Pier is designed to accept a wide variety of finished wood sizes distributed throughout the US. Depending on the wood in your area the 4"x4" post may fit loosely into the Dek-Block® pier, this is fine and does not need to be corrected. Once built and everything is secured your deck will be very sturdy. If you want you may place a shim on either side of the 4"x4" post but doing so is not necessary.

If your 4"x4" post seems too large or is not fitting properly you may have to remove some left over debris from the pocket of the Dek-Block® Pier. Occasionally you may have to drive the post in place using force from a hammer.

Metal Brackets

What Kind of brackets are available?

Though many of the decks do not require the use of brackets a few decks do. Also the builder may decide to use brackets for their own reasons. There are many different types of brackets and hardware available to see some of them click here.

What is a metal truss plate?

A metal truss plate is a smooth plate that joins two supports boards that are positioned end to end. You need something on each side to hold these two support boards together. You can also use treated plywood or scrap 2"x4" or 2"x6" treated material as well.

Do I need to use a metal bracket to secure the support board to the top of the 4"x4"?

No. You can if you would like to, but it's not necessary. Toe-screwing the support board to the 4"x4" post is sufficient. Use two screws from each side. If you go to your local home building store, they have several metal brackets that can secure a 2"x6" to the top of a 4"x4". One example is known as a Hurricane Tie, see illustration below.

Hardware

What Kind of hardware is available?

Most of the decks only require the use of a deck screw to assemble. Some of the pool decks however, also require the use of a lag bolt, and lag screw. To see some of the different kinds of hardware available click here.