Step By Step Process To Attach Railing Posts To A Deck Frame
One of the most crucial tasks you must complete correctly while building a deck is attaching the deck railing posts. Any deck that is 30 inches or higher above grade must have sturdy deck rails as specified by code. The posts must be installed correctly in order to avoid swaying, which can cause the railing to fail and cause falls, and they must be spaced closely enough to prevent children and dogs from slipping under. In addition to making your deck safer, properly attaching the railing posts helps you avoid legal trouble and moral embarrassment if someone falls off.
Step 1: Check Local Building Codes
- Check your local construction codes to be sure you are adhering to or surpassing their requirements before you start building your deck. Consider construction codes as a minimal requirement, or a passing grade, if you will. If you can, it is always preferable to go above and above the minimum standards.
- Building rules will probably stipulate minimum fastening requirements, such as the diameter of bolts and the appropriate connectors to use, as well as maximum post spacing (often 4' or 6' on center) and minimum railing height (I typically use a 42" railing when I build). In most places, you should meet or exceed construction codes, but you should still double-check. For instance, stainless steel fasteners may be necessary in place of hot-dipped galvanized ones near significant saltwater bodies to prevent premature corrosion.
Step 2: Post Height Calculations
- Add the desired railing height with the real (not nominal) height of your deck joists to get the right height of your posts for a specific railing height. For instance, a post that is 51 1/2" long is needed for a 42" railing with a 2x10 joist.
Step 3: Clamp Post And Blocking
- This process is used for deck sides that have rim joists. Read the "Modification for no rim joist" part near the conclusion, then start at step 1 for the sides where there is no rim joist.
- Place a clamp as shown in the second image, spanning 2 deck joists. Setting the post on top of the clamp will guarantee accurate measurement of the post's height. Put a piece of blocking that will fit between the deck joists against the post and clamp it there.
Step 4: Mark And Drill Holes & Add Bolts
- Mark a hole 2" below the blocking's top and 1" above the point where the joist meets the blocking (NOT on the center line of the post). Mark a second hole 1 3/4" over from the point where the joist meets the blocking and 2" up from the blocking's base (this WILL be on the center line of the post). Drill through the blocking, post, and rim joist using a 5/8" diameter drill bit that can go at least 7" deep. Make sure not to create an uneven hole.
- Through each hole, thread a 1/2" by 8" hot-dipped galvanized hex bolt with a flat washer. Use a 3/4" socket to tighten the bottom bolt after adding a washer and nut.
Step 5: Level Post & Add DTT2Z Tension Tie
- Verify that the post is upright and make any required changes before adding any more hardware. Keep in mind that for more accurate readings, close one eye and sight from directly in front of the bubble.
- A DTT2Z Deck Tension Tie should be attached to the post's top bolt. When finished, tighten the nut and add a flat washer. The clamps may be taken off at this point. Attach the tension tie to the deck joist by using a 3/8" socket and the screws from the DTT2Z.
Step 6: Screw In Blocking & Modification For No Rim Joist
- Fasten the blocking to both joists with three 3 1/2" deck screws on each side. Install 2 pieces of blocking perpendicularly between the final 2 joists on the sides of the deck where there are no rim joists, as shown in the illustration. Apply three 3 1/2" deck screws to each block's end. Make sure to leave enough room between them so that when you need to attach the screws to the tension tie, you can still fit your impact driver in there. Since my impact driver is quite short, you might require a somewhat larger space than what I needed—12".