A loose railing is one repair that shouldn’t be put off. Here’s how to re-anchor one that’s pulled loose from concrete:

Materials and Tools:

sawhorse
pencil
flat-head screwdriver
socket wrench
hammer
wood block
putty knife
hammer drill with 6-inch industrial hammer masonry bit
hacksaw
shop vacuum
metal file
woodworker’s clamp
C-clamp
knee pads
work gloves
plastic gloves
quick-dry cement
lag screws
5/16-inch threaded rod
5/16-inch nut and split lock washer

Steps:

1. Using a flat-head screwdriver, dig out a hole where the rail was mounted. Clear the area of debris with a shop vacuum.

2. Using the mounting bracket of the rail as a guide, drill a hole into the concrete with a hammer masonry bit.

3. Drive a 5/16-inch threaded rod through the rail bracket and into the new hole. Decide how much of the rod to leave above the surface, and mark for your cut. Leave enough room to add a lock washer and a nut.

4. Remove the rod and clamp it to a sawhorse with a woodworker’s clamp and a C-clamp. Cut it to length with a hacksaw. Smooth the cut edge with a file.

5. Mix up a small amount of quick-set cement to patch the hole below the rail base. Pack the cement in the hole and set the railing in place.

6. Insert the rod through the base and the cement and into the hole you drilled.Tap the rod down by holding a block of wood on it and hitting the wood with a hammer.

7. Place a lock washer and nut on the threaded rod. Partially tighten the nut with a socket wrench. If possible, secure the back side of the bracket by driving a new lag screw into the existing anchor. 

SITE SOURCE: hgtv.com/home-improvement/wrought-iron-railing-repair/index.html