How to Install a Deck Floor

There are many steps to building a deck, and one of the last is installing the floor. 

If you’re wondering how to space, measure, or attach boards, our tutorial will show you how. We are installing a redwood deck floor over the frame and joists we just built.

How to Install a Redwood Deck Floor 1

How to Install a Deck Floor

Before you begin throwing redwood boards down on your joists and frame, make sure you’re squared off and ready to lay them with precision. Here’s how to install a deck floor.

How to Install a Redwood Deck Floor 2

 Step 1: Measure

Run a tape measure along the outer frame where the two sides of your deck run lengthwise with your joists.

How to Install a Redwood Deck Floor 3

Mark every 12” along the outer frame.

How to Install a Redwood Deck Floor 4

Mark every 12” along the outer frame on the other side as well.

How to Install a Redwood Deck Floor 5

Step 2: Mark the Joists Every 12 Inches

Run a chalk line, matching the ends up with every 12” mark, and snap it across the joists every 12”.

How to Install a Redwood Deck Floor 6

The chalk lines will provide you with a gauge to square up against. It will keep you on track, so you don’t end up slanted at the end of your deck.

How to Install a Redwood Deck Floor 7

Step 3: Decide Where Your First Board Will Go

If you have a curved aspect of your deck, start at the outermost part of the curve. (See this tutorial on laying a curved deck floor.)

Also, consider the possibility of abnormalities within the deck floor. For example, this electrical conduit (pipe) must come up through the corner of the deck to enter through the house wall.

How to Install a Redwood Deck Floor 8

So, we measured, marked, and drilled the hole for that pipe in our first board.

(Of course, if your obstruction comes in the middle of your deck, you’ll have to deal with that when you get there. Unless you want to start at the point of obstruction and work your way outward. It’s a judgment call you have to make based on your specific setup.)

How to Install a Redwood Deck Floor 9

Sand the edges of the hole so the top of the deck floorboard is smooth.

How to Install a Redwood Deck Floor 10

The board is now ready for us to place.

How to Install a Redwood Deck Floor 11

Step 4: Install Your First Board

To lay our redwood deck floor with 2×6 pieces of wood, we will be using a Camo brand deck spacer. Once you use this tool, you’ll never want to use anything else to build a deck.

How to Install a Redwood Deck Floor 12

It works by squeezing the lever upward, which extends outward two metal spacers at either end of the tool.

How to Install a Redwood Deck Floor 13

Keeping the lever squeezed, place the Camo deck spacer on the redwood 2×6 at the point that is both parallel and centered over a joist. Release the lever to contract the two metal spacers, and clamp the deck spacer tool in place.

How to Install a Redwood Deck Floor 14

Then use the appropriate size Camo screws (in this instance, 2-3/8” screws for a 2×6 deck floor) to screw into the holes on either side of the deck spacer.

How to Install a Redwood Deck Floor 15

Installation Tip: Using a Camo Deck Board Spacer and Installing Level Boards

Now, let’s talk about technique. We found it most effective to begin at the most stable/immovable side of the deck. In this case, that is the house wall side.

Clamp the deck spacer above the frame here, and screw the redwood board in place, leaving about a 1/4” gap between the end of the board and the house.

How to Install a Redwood Deck Floor 16

Be sure the obstruction is threaded up through the redwood board, if applicable, before attaching. 

How to Install a Redwood Deck Floor 17

The method we found most effective involves three workers per board. Two workers use a deck spacer on neighboring joists, while the third worker levers the board’s end to keep it parallel.

(Note: These are 16’ boards to cover about a 13’ deck span because whenever possible, it’s best to have seamless deck floor boards. So there is about 3’ of excess at the end of each board. )

How to Install a Redwood Deck Floor 18

Use a pry bar to push or pull the end of the board so that the Camo deck spacer is snug.

How to Install a Redwood Deck Floor 19

As you work your way outward from the house (or your most stable deck side), you will have the two-deck spacers set, then the pry bar set and pushed or pulled as needed to keep the board snug. Then you’ll insert the screws through the deck spacers and release the pry bar.

Remove the Camo deck spacers and repeat the setup on the next two joists down the line.

How to Install a Redwood Deck Floor 20

The third worker often doubles in duties of horizontal pressure, with the pry bar set and secured, as well as vertical pressure, standing on the board so it’s flat against the joists or frame.

How to Install a Redwood Deck Floor 21

Here’s another instance where, near the end of the 2×6 board’s installation, the third person will stand between the two deck spacers in order to secure the board against the joists.

How to Install a Redwood Deck Floor 22

Installation Tip: How to Straighten Curved or Bent Deck Floor Boards

Sometimes boards will be bent just enough that it’s hard to use the deck spacer. When this happens, use wooden shims to widen the gap enough for the deck spacer.

How to Install a Redwood Deck Floor 23

Place the deck spacer, so it is flush against the top of your redwood board.

How to Install a Redwood Deck Floor 24

Then you can either remove the shim and install the screws or keep the shim there while you install the screws. It doesn’t make much difference.

How to Install a Redwood Deck Floor 25

An alternate method for creating enough space is to use a small crowbar between the two boards. Pull or push it to give your deck spacer some room, then remove the crowbar after the spacer is in place.

How to Install a Redwood Deck Floor 26

Working your way from the house (or the most stable side) down to the other edge of the deck allows you to use the end of your redwood 2×6 as leverage for pushing/pulling it into place. Remember that wood isn’t precisely straight, and you can manipulate it to a large extent to lay where and how you want.

How to Install a Redwood Deck Floor 27

Step 5: Work Your Way From One End of the Deck to the Next

You can see here the line of Camo screws installed along this joist. That’s what makes using a deck spacer like this so wonderful – the proof of installation is almost invisible when all’s said and done.

If you want your deck floor to look seamless, use a tool like the Camo Spacer to screw the boards down.

How to Install a Redwood Deck Floor 28

Step 6: Allow Your Boards to Overhang Your Deck

Allow the ends of your boards to overhang the edge of the frame where possible. Be sure to use the deck spacer on both of your doubled-up outer deck frame pressure-treated boards.

How to Install a Redwood Deck Floor 29

If the overhang distance is too great or you need to use the excess lumber, use a circular saw to cut the ends off the outside edge of your board. Leave an inch or two of overhang so you can do a final precision cut along your deck edge before you start to trim.

How to Install a Redwood Deck Floor 30

Installation Tip: How to Work Around Obstructions

If you run into obstructions, like this 6×6 cedar pergola post coming up through the deck floor, you may need to use large clamps instead of the pry bar to keep the board in place.

How to Install a Redwood Deck Floor 31

It’s easy to chisel bits of the board as needed. Simply use a jigsaw, then hammer and chisel the rest of the wood out. The pergola post infringed on the next redwood board in this example, so we had to remove a small sliver.

How to Install a Redwood Deck Floor 32

Then use the Camo deck spacers above the joists and/or frame to keep the board in place before mounting.

How to Install a Redwood Deck Floor 33

Always put downward pressure on the board and/or the Camo deck spacer as you’re installing the screws. You never know when a board is lifted off the joist a little. 

How to Install a Redwood Deck Floor 34

We will trim the bottom of the pergola posts, so we didn’t sand or finish the edge. The important thing is that the 2×6 redwood board fits around the pergola post, and the board maintains its parallel layout for the rest of the deck floor.

How to Install a Redwood Deck Floor 35

Installing a deck floor is a process of working methodically, from stability outward. In this example, we worked from the board closest to the concrete steps outward, with each board being secured from the left (secured side) to the right.

How to Install a Redwood Deck Floor 36

Step 7: Install Your Outermost Flood Board

When you get to the very outer floor board, measure the widest distance from the second board’s edge to the outer edge of your frame. (Hopefully, this will be the same distance all across, but in case it’s not, make sure you take the widest distance.)

How to Install a Redwood Deck Floor 37

Mark this distance, and run the last board through a table saw to create the precise width you need. Install in the same way, with Camo deck spacers keeping the space and predrilling/screwing on the very outer edge.

How to Install a Redwood Deck Floor 38

You’ve just completed laying the redwood deck floor.

How to Install a Redwood Deck Floor 39

Redwood is just beautiful on a deck floor.

How to Install a Redwood Deck Floor 40

While you may still want to add trim, you can start to envision what a gorgeous asset this redwood deck will be to your home, yard, and life.

How to Install a Redwood Deck Floor 41

With the floor installed, you’re almost ready for stain and sealant.

We hope you enjoy installing your own redwood deck floor and that the end result is something you can use, enjoy, and be proud of.