Yes a polyurethane finished hardwood floor may have additional coats of polyurethane applied.
Apply extra coat on prefinished hardwood.
It cannot be done.
The urethane used in sealing wood surfaces is more commonly known as polyurethane.
There is no way you can ever manually duplicate the factory coating.
Before you attempt to apply polyurethane to a prefinished floor contact the flooring.
I read the question about the differences between laminate hardwood and pre finished.
But since the introduction of prefinished solid hardwood during the 1940s this newer form of flooring has become increasingly popular and today you may find that it s easier to find than traditional unfinished hardwood planks.
Forget the notion of trying to fill sand and re seal with your own coating.
Keep the floor clean use furniture floor protectors and expect to apply a new coat of polyurethane on the floor every five to.
As noted the prefinished allows for the possibility of spills going through the slats.
Lightly sand with a dull 120 to 150 grit abrasive screen or 2 steel wool under a heavy floor buffer.
Whether you can seal a prefinished floor with polyurethane depends on your circumstances and the condition of the hardwood floor.
In general factory finishes and comparable coatings you apply by site finishing such as polyurethane take little maintenance.
Difficult to repair if pre finished hardwood flooring gets scratched or dented during installation you have no option but to replace the entire floorboard.
Can prefinished hardwood be sealed to avoid this problem.