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Simple trick to set dead-level posts
Apr 11, 2014
Setting dead-level posts to support a deck or stairway railing is easy if you know one simple trick. Before I was taught how to do the job correctly, I wasted a lot of time fiddling with posts until I was satisfied they were level.  My problem was that I’d drill the bolt holes to secure the base of the post to a deck’s rim joist or a stair’s stringer all at the same time.  The skewed result was a constant disappointment. it wasn’t until I worked with a professional deck builder at Victoria Beach that I learned the solution to the problem. 
Mark the spots where posts are to be set, then hold a post in place (it’s always easier with two people) and place a level on one side. Drill a hole through the post and the rim joist the same diameter as the bolt (let’s say 3/8 inch). Tap the bolt through the hole with a hammer and then tighten the washer-backed nut on the opposite side until the post is drawn firmly to the joist. 
Place the level back on the post, adjusting the post’s position to dead-level by knocking it gently with a rubber hammer or a sturdy fist. 
Now drill the second hole through the post and joist, tapping home the bolt and fastening the nut with just enough torque to hold the post in position: reefing can damage wood fibres, possibly causing damage to the post. Be sure to stagger the holes to prevent a check from opening at the base of the post and running through both holes, weakening the post. (Some designs call for three bolts per post, especially if six-by-six-inch timber is used. Be sure to stagger these holes, as well.)  Drilling a single hole to begin with will ensure accurate results 100 per cent of the time. 
Generally speaking, hot-dipped carriage bolts are used to secure posts to joists because their domed heads are more attractive than hex-headed machine or lag bolts.  The main advantage to the hex-headed design is that the bolts can be quickly tightened with a drill with a ratchet head in the chuck. 
With lag bolts, pre-drill the post with a bit of similar diameter to the bolt and use a washer so the head is not buried in the wood.
If you use a cordless drill for this purpose, you will require a fully-charged 18- to 20-volt tool to supply sufficient torque. Though cordless products are convenient, I use a 3/8-inch to half-inch cord drill whenever possible, since the torque is about 10 times that of a cordless, and the plug-in tool will run all day without variations in power due to battery fatigue. 
Standard deck planking is 2-by-6-inch lumber or, in some cases 5/4 (1 ¼)-by-6-inch composite material or treated wood with a round or radial edge. Green treated 2-by-8-inch joists spaced 16 inches to 24 inches on centre (OC) are recommended for 2-by-6-inch planks, while 12 inches to 16 inches OC spacing is required to provide adequate support for 5/4 wood decking and 12 inches for most composite material. (It is advisable to check with your local building inspectors as construction specs vary throughout the city and province.)  
A permit is required to build any deck, whether attached to your house or free standings. Decks two feet or less in height do not require a rail.
Basic deck hardware consists of galvanized hangers nailed or screwed to the beams and joists to support the joists, as well as stainless ($12-pound) or ceramic 2 1/2-inch or 3-inch green or brown ($5.50-pound) to fasten deck boards to the joists. If you have access to a pneumatic nailing gun, galvanized hot-dipped spiral nails (3 1/4-inch) are recommended for the job at $50 per box of 1,500 from Prime Fasteners.  Uncoated nails or screws will be destroyed by the arsenic in the solution used to preserve boards. 
Pre-built wood stair stringers can be purchased for about half the cost of metal ones, but, for the most part, wood stringers are poorly constructed. It is well worth sorting through the selection at a lumber store to find wood ones that are not missing a tread support or otherwise damaged. Steel stringers are well built and, to my mind, it is worth paying $19 for a three-step steel stringer compared to $11 for a similar size one. 
The number of stringers required to build a set of steps depends on the tread thickness, length and total rise of the staircase. As a rule of thumb, three stringers (24 inches OC) are required to support a four-foot-wide stairway with a total rise of five feet.