Toilets do not mount to the floor. The toilet maintains stability through an adhesive wax ring and bolts attached to a floor flange. The floor flange is a circular piece of plastic that inserts into the toilet drain and bolts to the floor. A wobbly toilet usually indicates that the flange is loose. Proper installation of any toilet requires that you seat the flange into the flooring material. Properly seating a flange onto a wood floor is relatively simple.
Scrape and clean the area surrounding the toilet drain. Closely inspect the area for signs of damage. Climb under the room through a crawlspace or basement, if applicable, to inspect the wood beneath the drain. You should not see any light through the subfloor. Hire a contractor to replace the subfloor if there are excessive signs of mould or decay in the area surrounding the drain pipe.
Position the toilet flange into the drain pipe. The flange has two long slits that hold the toilet bolts. Make sure the ends of the slits, where the bolts will sit, are positioned properly. The bolts correspond to the sides of the toilet. Place a straight edge stretched across the ends of the slits so that it makes a line between the two. The straight edge indicates the angle of the toilet, which should be parallel to the wall for toilets that project straight out from the wall. Adjust the flange as necessary to achieve the proper angle for your toilet.
Screw the self-tapping screws into the floor through the designated screw holes on the flange. The flange will have three screw holes on the surface. Angle the screws away from the centre as you drill them into place so that they fully grip the floor.
Grasp the flange and attempt to wiggle the flange. You should be unable to move the flange at all. Movement of any form indicates that the screws failed to grab the wood. Readjust the position of the flange and repeat the process.
Install the toilet following the manufacturer's recommendations.