# How many deck piles do I need?

When applying for a deck permit in Edmonton, you will need to indicate the beam size you are using. The beam size required is determined by the spacing of your piles. Here is a visual breakdown of how to determine the number of piles needed for a deck that is attached to your home (ledger board).

### Legend

**Beam**

**Piles**

**Joists**

**Ledger Board**

**Beam Cantilever**

**The beam** cantilever is the distance from the end of a **beam** to the first contact point that rests on your deck posts.

The maximum **beam** cantilever in Edmonton is 16 inches ( 1' 4").

### Method 1 - Piles Spacing

Begin by measuring the total deck width minus the desired **beam** cantilever (max 16" or 1' 4").

In this example, we have a total deck width of 23' 8". We chose 16" cantilever for both ends, which gives us 21' beam span.

**Next, we divide this 21' span into sections so that we have less than the maximum beam span allowed.**

### Maximum Beam Spans Edmonton

2 - 2 x 8" 3 - 2 x 8" 3 - 2 x 10" 2 - 2 x 12" |
7' - 6" 9' - 9" 11' - 11" 13' - 10" |

In our 21' example, when divided into two sections we have a measurement of 10' 6". Looking at the Max Span column this is less than (3ply) - 2 x 10" **beam **| 11' 11" | and (2ply) - 2 x 12" | 13' 10" |. Choosing one of these options we would need a total of three **piles **for the front face of our deck.

Another option would be to have four piles. We do this by dividing our 21' span into three sections of 7' - this allows us to use any of the four **beam **options.

###### Using shorter beams such as 2x8 may be necessary when the height of your deck is low.

### Method 2 - contact point to contact point

The first method is a quick way of finding how many piles you will need for your deck and can be used in most cases.

- Total Deck width
- Minus Cantilever's
- Minus post width's
- Divided
- Equals
**beam**span (sections)

The **beam** span tolerance is precisely measured from the inside contact point that the **beam** rests on the post, measured to the adjacent inside contact point. We used 6 x 6 posts. So the true span with three **piles** is 21' minus three 6 x 6 post widths. When divided into two sections each span is 9' 9" which is eighteen inches shorter than the first method. For our example deck using the contact method, we are able to use a 3ply 2x8 **beam** that would not have passed using the first method.

Most of the time the first method is enough, thou occasionally you may be trying to reduce the number of **piles** used or looking to fit a smaller **beam**. This contact point to contact point method will give you a true beam span.

###### It's not a bad thing to have a stronger beam than necessary.

### Step 2 - How many rows of piles?

Depending on the distance of your deck away from your house (ledger board) and the size of **joists** you use. You may need another row of **piles** to support an additional **beam**. Similar to **beams**, **joist** size and spacing have different maximum **joist** spans.

### First measure the distance of your deck away from your house. Our example is 15' 3 1/2"

Our **joists** will also have a cantilever (**joist** overhang past the **beam** that it rests on).

#### There are two **joist** cantilever maximums.

- 2x6 and 2x8
**joists**have a max of 16" (1' 4") - the same as**beams**. - 2x10 and 2x12
**joists**have a max of 24" (2')

Using the maximum **joist** spans table we can find the appropriate **joist** dimensions.

### Maximum **Joist** Spans

2 x 6" 2 x 8" 2 x 10" 2 x 12" |
9' - 4" 11' - 7" 13' - 8" 15' - 7" |
8' - 2" 10' - 9" 12' - 11" 14' - 8" |

Our example deck is over 15' - so lets use the 2 x 10 / 2 x 12 maximum cantilver of 24" (2').

Next, minus our chosen cantilever measurement and **beam** width from our total deck distance away from the house. This equals 12' 11" in our example.

According to the max **joist** span table, we can use 2 x 10 and 2 x 12 at both 16" o.c. and 24" o.c.

###### To reduce the cost of lumber in this example, we would use 2 x 10 at 24" o.c. Which has a maximum **joist** span of 12' 11".

**o.c. (on center) **

- Refers to the spacing between joists. Tighter spacing has a larger joist span allowance.

24 " o.c. |
16" o.c. |

### Another row of **piles** and beam would need to be added if we use 2 x 8 or 2 x 6 joists.

Sample images of adding a second row of **piles**.

**Other factors that affect the number of deck piles you will need.**

- Multiple deck heights
- Angles and curves.
- Deck pattern

If you have questions about decks or are looking for a quote, please contact us at any time. Or check out or landscaping site

### Already have a deck?

We have many landscaping materials to cover the area under your deck to keep weeds and other vegetation under control.

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