Why Do You Need A Deck Ledger Board?


Planning on building your deck but still figuring out what is needed. Do you need a deck ledger on your deck?

A deck ledger board is needed to support one end of the deck joists with a deck beside a house. The ledger is fastened to your adjoining home, distributing half of the deck weight and live load (forces applied to the deck such as furniture, people, etc. Supporting half the decks weight using the house’s foundation to support the joists replacing the beam, post and footing required with a freestanding deck.

When do you need a ledger board, and when do you not? Why is it so important? Can it be left off decks attached to a house? How necessary is it really? This article answers all these questions and gives you insight into deck ledger boards.

Before going into more details let’s define a few terms.

What Is A Ledger Board?

Let’s quickly look at the ledger board to determine when you may or may not need one. A ledger board is a pressure-treated piece of dimensional lumber that attaches a deck to the frame of a house. Often the deck joist will be attached to the ledge board using joists hangers.

The ledger board is typically bolted or screwed into the structural frame of the adjoining home, and the joists are attached to the exposed area of the leger board.

Do You Need A Deck Ledger Board?

The simple answer depends if you are building a freestanding or attached deck beside your house. A freestanding deck will not require a deck ledger, even beside your house. But an attached deck will be attached to the house using a ledger board.

I have seen decks built without ledger boards. The hangers nailed directing to the house’s rim board, but this is not good construction practice, which we will get into.

If you are connecting the deck to an adjoining home, then regulations and building code state you will need to include a ledger board.

If you do not want to use a ledger board, please read my article Building a Deck Beside the House but NOT Connected to the HouseOpens in a new tab.. Where I go into much more detail about constructing a detached deck without a ledger board.

Why is A Deck Ledger Board Necessary?

In most decking building cases, a ledger board is paramount in providing the deck with rigidity and stability. Approximately half of the weight of the deck and then the live load is supported by the ledger board attached to the house’s frame.

The International Residential Building CodeOpens in a new tab. (IRS) requires that all decks be built to support 50 lbs per square foot. Including 10 lbs of deadweight ( the deck material itself) and 40 lbs of live weight (everything on the deck like furniture and people the important stuff) per square foot. Your house wall by itself is not designed to support this type of weight. Hence the deck ledger.

The attached ledger board receives structural support from the foundation of the adjoining home while distributing the weight of the deck on the house. The rest of the weight is supported by the deck structure, replacing the beams, posts, and footings.

Think of the deck ledger like a beam for the joist on one side fo the deck.   

Not having a ledger board or an inadequate one will result in the deck’s collapse. Thus, a deck is attached to the adjoining home will require a ledger board in all cases. However, there is one scenario where a ledger board is not required.

When Do You Not Need A Ledger Board?

As we said, you will not require a ledger board if you wish to build a free-standing deck that is not attached to your house. A free-standing deck may appeal to many individuals for many reasons and is significant because this means you will not have to make any modifications to the outside of your home if you build a deck this way.

Considering Factors For A Free-Standing Deck (No Ledger Board)

Before you even start to plan a free-standing deck, you will need to check with your city to determine the regulations and codes for a deck. Depending on where you live and the type of free-standing deck you wish to build, you may require a permit.

A freestanding deck beside your house will still require a permit after a certain height from the ground, often 30” in the states, 24” in Canada.

Another factor that will influence the choice of a free-standing deck is the eligibility of the ledger board being able to be secured onto the adjoining house. More factors would include the deck’s location (perhaps the area where you wish to place the deck will not allow for a leger board) and the builder’s preference.

You also might want to consider a free-standing deck because a deck attached to your home might increase property taxes. This is because it is viewed as a living space and will increase your home’s square footage.

When planning, preparing and building a free-standing deck, you will need to consider that the ledger board (which will not be there) will not support half the weight of the deck and live load. Thus, some weight distribution calculations have to be taken into account and adjusted. Including the adding of additional footing, deck posts, beams, and cross bracing. However, that is beyond the scope of this article. Need more information about deck partsOpens in a new tab., click the link for full explanations and valuable links to relevant information.

When Do You Need A Ledger Board?

You will need a ledger board if the city in which you live denies the permit for a free-standing deck that you want to build, or if you are renting a property and the landlord will not permit you to build a deck in this fashion.

This means that you will have to attach the deck to your house and, thus, will need a ledger board. Furthermore, as discussed above, you will need to use a ledger board in all situations where you need to attach the deck to the adjoining house.

Conclusion

We discovered that, in fact, if you are building and attaching a deck to your house, then you will definitely need a ledger board. This is because the ledger board aids in the distribution of weight from the deck and the live load.

The only situation where you will not require a ledger board is if you plan to build a free-standing deck. However, this poses its problems (permits, determining load on other support structures, etc.). Although many people still opt to choose this type of deck.

Ryan Nickel

A Red Seal carpenter, passionate about building decks to be enjoyed.

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