Table of Contents
What size lag screws will you need? It all depends on your unique circumstances, but typically ½-inch diameter lag screws will get the job done. First, pre-drill 5/16-inch holes through both the rim joist and ledger, then drill a ½-inch hole through the ledger alone.
What size bolts should use for deck posts?
You need a different type of screw for each part of your deck. An 8 gauge, 2.5” coated deck screw is most commonly used when fastening deck boards to joists. For deck framing, structural wood screws such as Simpson SDS 1.5” screws work with joist and stringer hangers, as well as post/beam brackets.
Can you use lag screws for deck posts?
At connections carrying structural loads, such as deck ledgers or railing posts, use through-bolts or lag screws. Through-bolts are stronger and should be used where possible. For the heaviest connections on a deck, such as where ledgers attach to the house or to posts, use 1/2-inch bolts or lags.
What size lag bolts do I need?
Measure the width of the combined pieces. Select a lag bolt that’s 1/4 inch shorter than the accumulated width of the two pieces. In most instances 5/16-inch-diameter lag bolts are sufficient. For larger or heavy-duty joints use a 3/8-inch-diameter or bigger lag bolt.
Can you use carriage bolts for deck posts?
Deck Posts Do not notch the 4×4 railing posts. The 4×4 railing post should be bolted to the inside of the joists using two ½”x6” galvanized carriage bolts. Corner posts use a third carriage bolt inserted through the adjacent joist.
What is the difference between a lag bolt and a lag screw?
What is the difference between a lag bolt and a lag screw? In practice, there is no difference in the terms. They are used interchangeably to refer to the same fastener. Technically speaking, lags should be referred to as screws, not bolts.
Are lag screws as strong as carriage bolts?
Just as we explained that the lag bolts are quite strong, so are the carriage bolts. Depending on the lag bolt’s grade and the application in which it is installed, you will find that lag bolts can hold up to thousands of pounds. The shear strength of carriage bolts also tends to be relatively high.
How long should lag screws be for ledger board?
The most common method is to install ½” lag bolts with washers or carriage bolts with washers. You will usually need the length of the bolt to be at least 4”- 6″ to penetrate through the 2x ledger board, the house sheathing and into the solid house rim.
How far apart do deck posts need to be?
For Building a Deck Railing, Deck Frame, or Fence The maximum spacing of 4×4 deck posts should be 6 feet on center, while the maximum spacing of 6×6 deck posts should be 8 feet on center.
How do I strengthen my deck posts?
Reinforce post connections Strengthen post connections with carriage bolts. Drill holes, knock the bolts through, then tighten a washer and nut on the other side. Ideally, posts should sit directly under the beam or rim joist to support the deck.
How big should a pilot hole be for a lag bolt?
Pilot hole size can range as follows: Soft Wood 40% to 70% of the shank diameter for wood with G ≤ 0.5. Medium Wood 60% to 75% of the shank diameter for wood with 0.5 < G ≤ 0.6. Hard Wood 65% to 85% of the shank diameter for wood with a specific gravity (G) > 0.6.
What size hole do you drill for a 3/8 lag bolt?
Pilot Hole Diameter for Lag Bolts Bolt Dia Shank (Unthreaded) Pilot Hole Dia 3/8 3/8 15/64 7/16 7/16 9/32 1/2 1/2 5/16 9/16 9/16 23/64.
What size hole do you drill for a 1/2 lag bolt?
Lag Screw Pilot Hole Diameters Nominal Diameter of Lag Bolt, inches Shank (Unthreaded) Portion, inches Diameter of Pilot Hole, inches (Thread Portion) 3 ⁄ 8 3 ⁄ 8 15 ⁄ 64 7 ⁄ 16 7 ⁄ 16 9 ⁄ 32 1 ⁄ 2 1 ⁄ 2 5 ⁄ 16 9 ⁄ 16 9 ⁄ 16 23 ⁄ 64.
How many lag bolts do you put in a ledger board?
Since 2009, every edition of the IRC (including the anticipated 2021 edition) requires the deck ledger to be connected to the house floor band joist with ½” bolts or lag screws as shown in Table 507.9.
Can you use 2×6 for deck joists?
2×6 joists should only be used on ground-level decks that do not require, and will not provide for, any guards. Most decking is not strong enough to support longer spans than 16″. Some builders reduce joist spacing to 12″ on center to strengthen the deck frame or to increase maximum allowable joist spans.
Can I use 4×6 for deck post?
Size of the deck Most professionals will encourage you to consider going with a 6×6 deck post form the outset of the project. Decks that are going to be built higher than just a few feet off the ground will likely need something more substantial than a simple 4×4.
What accounts for roughly 90% of all deck collapses?
About 90% of deck collapses occurred as a result of the separation of the deck ledger board from the house, allowing the deck to swing away from the house. It is very rare for deck floor joists to break mid-span. Many more injuries are the result of rail failure, rather than complete deck collapse.
Do lag bolts need washers?
Another important consideration when fastening with a bolt (regardless of whether it is a through-bolt or lag bolt) is the use of washers. A washer adds to the bolts area of holding power. The bigger the washer the better the holding power. Even better than a lock washer is a lock nut.
