What is a Ledger Board?
You probably hear a lot about wooden boards – like deck surface boards, beams, and joists when you discuss decks. However, you may hear a little less about a ledger board. What is it, and what is its purpose? Let’s check out what this critical board is and what it does.
A ledger board, also called a ledger, is the horizontal board which secures and attaches a deck to a house or building. The ledger board is crucial, as it helps support the deck and fastens it to the house wall. A poorly designed and installed ledger board could risk the deck’s structural safety.
Ledger Boards in Deck Building
As you can imagine, deck ledger boards are critical in deck construction, primarily because of two reasons. First, it keeps the deck attached in a stable position to the house or structure, and second, this board braces some of the deck’s weight.
Ledger Board Materials and Types
In my opinion, two main kinds of material are suitable for this all-important support board. A common type of ledger board is pressure-treated wood, such as pine. Pressure-treated wood has a preservative added to it, so it’s more resistant to rot and also to insects, like termites and carpenter ants.
Another type of ledger board is engineered wood like composite, plywood, or oriented strand board. There are a few types of engineered materials for a ledger board. Do your research, as there are benefits and drawbacks to each one. A little planning will go a long way to helping you have a successful deck project.
- Laminated veneer lumber (LVL) is a good choice. Wood layers make this board that are held together tightly with resins and glue.
- Laminated strand lumber (LSL) are small pieces of wood arranged in an angled pattern. This type of engineered wood is quite dense.
- Oriented strand board (OSB) is compressed wood flakes – or strands of wood – with adhesives. This is often used in roof sheathing and flooring, such as floor joists.
- Medium-density fiberboard (MDF) is another suitable possibility. It’s a dense wood substance made from fibers of both hardwood and softwood.
- Composite board consists of wood fibers and recycled plastic. The ledger board also includes MDF and OSB, making it one of the most sustainable options.
How to Choose the Right Ledger Board for Your Deck
There are a few considerations to keep in mind while deck building. To avoid potential problems like stability issues, mold (which leads to decay and rot), and even a deck collapse, follow the IRC guidelines. The International Residential Code, or IRC guidelines, are vital in keeping structures like decks and buildings safe and functional.
Depending on the type of deck you want to build – and the house you have, I can recommend several methods of attaching the ledger board. Additionally, another factor to consider may be the year your house was built. For example, if your house is newer and built after the mid-90s, it may have a manufactured wood joist system. This would affect how the ledger board is connected. It’s always best to consult a building inspector or engineer when planning and constructing your deck.
Ledger Board Installation: Attaching a Ledger Board for Your Deck
Besides adherence to building codes, some other variables are paramount to a firm foundation and strong deck frame. There are two general concerns regarding anchoring a deck to a structure like a house. First is the flashing: you must have flashing in place for a quality deck build. Another vital aspect is that the fasteners must be the correct ones and kept in top shape. It’s best to use hex or carriage bolts. If you use lag screws, check them regularly, as they can strip out of the wood.
Secondly, keeping the ledger board and surrounding areas well maintained and waterproofed is significant because this will not only prevent mildew it will lengthen the life of your deck and house exterior and framing. I recommend using flashing tape to keep water out of the ledger connection to your house.
Bearing these two points in mind, here are a few steps to help you prepare for your new deck or to reinforce your existing one.
Consult With a Code or Building Inspector and Contact Miss-Utility
In the planning stages, do your due diligence. Find the buried utility lines, map out your deck, and talk to a municipal building department inspector or engineer.
Pick Out Ledger Material, Spacing, and Fastener Choices
Once the planning stages are complete, it’s time to install the ledger board to your house frame. Protecting it from mold is critical to ensuring your deck lasts for years. Do not rush this part.
Preserve the Structure
Last, managing the amount of moisture that comes in contact with your deck and its joists and mitigating water damage are central to maintaining your deck. Caulking around doors and windows can help keep precipitation out and prevent potential water damage.
Building Codes and Regulations Related to Ledger Board Installation
Pay special attention and adhere to building codes. Follow the IRC, as referenced before, and check with your local jurisdiction regarding construction and building guidance. International residential codes specify “approved corrosion-resistant flashing.” IRC section R703.4 is worth a look at regarding the assembly of decks, substructures, and ledgers.
Also, joist hangers, rim boards, and band joists all have their own specifications, as well as any deck hardware. The fasteners need to be correct to fortify the deck and its support system.
Most Common Mistakes Made During Ledger Board Installation
In my years of experience, I’ve seen a few mistakes – some big, and some which are correctable. Let’s see what some of these errors can do in the way of hindering the deck-building process.
1. Incorrectly Attached Ledger Board
Incorrectly attaching the ledger board is one of the mistakes people make that is fundamental to the deck’s composition and safety. Please install and anchor the ledger properly to avoid catastrophic consequences. Incorrect fasteners, like lag bolts, nailing the ledger board to the house, and needing to have the ledger board attached to the rim joist, are all formidable mistakes that can lead to a deck collapsing.
2. Incorrect Joist or Beam Spacing
Speaking of structural collapse, the spacing between joists is another mistake to avoid. What I have seen is that some DIYers need to be more precise, leaving too much space between these essential bracing beams. Because the weight of the deck is distributed per square foot between the joists and the ledger board, the importance of this cannot be overstated. The live load is a weight or load that can change (think people or furniture), while a dead load is the static, unchanging load or weight of a deck. The environmental load is applied by the environment or forces of nature.
3. Using the Wrong Deck Fasteners
I have often seen this mistake happen because of either misinformation or cutting corners. Make sure to use deck screws, bolts, and washers that are resistant to rust and corrosion. Water can get in and damage these parts quickly, so it’s best to find sturdy metal materials such as stainless steel or hot-dipped galvanized. I recommend applying butyl joist tape to help keep screws dry and in place.
4. Skipping Flashing Tape
I see lots of new (and existing) decks that don’t have proper flashing. Proper ledger flashing is necessary for making your deck water-resistant and protecting it above and below the surface from mildew. Easy-to-install Trex Seal flashing tape is a valuable tool to assist with this. It shields the ledger board from moisture. I often tell builders not to skip this step.
You’ve built something amazing, fun, and beautiful. You want to enjoy your deck, entertain your friends, and keep your family safe. Isn’t it worthwhile to build your deck the right way? With some pre-planning, research, and expert advice, you will have a sturdy and gorgeous deck that will last many years.