The newel for the stair rail fits over the top of the Sure-Tite bolt. After bolting in tightly. Check it for plumb on both sides. Cut the bottom to adjust and reinstall. This method of attachment takes a little more time. The results are superior to metal brackets with moulding to hide them. My objection to 4j anchors is two fold. The screws loosen over time. ( I have repaired many) The aesthetics are ugly to me. I like the plain simple connection of post to floor without adding a piece of moulding that looks like your hiding something.
newel post anchored with a Sure-tite fastener
Determine the handrail length by measuring at the bottom between the points. Check that the walls are plumb and again adjust if necessary. After cutting the stair rail to length we put in the rail bolt holes. Pics below
drilled for rail bolt
stair rail drilled for balusters
Using a 1 inch sharp paddle bit, drill the hole for the rail bolt captive nut. Forster bits work fine as well. You can use a forstner bit. I prefer the spade bits because they are easily sharpened. Then using a 3/8 bit drill the end hole for the rail lag bolt. Pic is below. From the bottom of the rail this is 7/8 to center. Try not to go much higher as it makes it tough to thread on the captive nut.
Rail bolt hole in railing
Measure in on each end of the rail for the starting balusters. I use 2 3/4 inch, again this is the starting and ending baluster in your rail. Measure between these points to determine your baluster spacing. 4 inch on a guardrail and 4 3/8 on a rake rail. Those are the inside spacing between balusters.
Install the rail bolt lags into the newel post. You will need to calculate the height from the floor to the center line of the rail lags.
installing rail lag into newel post with a rail wrench
Now you can install the rail between the posts. I keep the newel post bolts loose until this step. Tighten them down at this point. Then install the rail bolts into the railing. You will need a rail wrench like the one pictured above.
We then use a laser to mark the floor, indexing on the rail holes above to the location on the floor for the baluster holes.
marking floor beneath stair rail for baluster holes
We started a new railing today. It is a L shaped guard rail with two full posts and a half wall post. It will have twist and basket series iron balusters. Clear coated by client. We gave a quick lesson on how to coat the wood with lacquer. He did a great job. This will save them about three hundred dollars. It all adds up.
First step is to layout the posts and get them drilled for the post anchors. I prefer to use the Sure-Tite brand utilizing a 5/8s threaded rod into the floor. It is a much stronger connection provided there is structure under the floor to grab it. (floor joist)
Sure-Tite newel bolt
Notice the first part of the hole is drilled wider. On floors with multiple layers, if you don’t. the screws in the Sure-Tite will wedge the oak floor up off the sub floor. Even lifting just a little WILL effect the connection of the newel post. The post will wobble if everything is not tight. ( sounds like experience ). The instructions have you drill a 5/8 s hole through the first 3/4 floor then a 3/8s bit down 6 inches. You can angle the hole to hit floor joists. Then use a hammer to straiten it. I use a paddle bit with an extension. I also keep a 3/8s high speed bit handy in case I hit a nail or Simpson tie.
Now we calculate our height, IRC (International Residential Code) guidelines are 36 to the top of the handrail in residential construction. You are allowed to go higher. I set this one at 36 1/4 off the finished floor.
I layout and drill a hole in the center of the newel. Another one cross drilled to catch the nut and washer. Pics below.