Sanding a wood floor is not a job that a homeowner should take on themselves; this work is often more difficult and time-consuming than you realise, and not hiring a contractor can mean a floor that is actually damaged and unsightly. Note how this can happen and three important reasons why you should always leave a floor sanding job to a professional.
The sanders that professionals use for sanding floors are not typically available for homeowners to rent, as they're very heavy and difficult to manage. Without proper training, they can even be dangerous, as they might get away from the operator; this can increase the risk of injury and damage to a home. However, underpowered floor sanders, such as those you rent from a hardware store, often don't have enough power to cut through wax, sealant, paint and other coatings. They may also be smaller so that it takes much longer to sand all your floors. A professional will have the right equipment to do the floor sanding properly and quickly.
It's not unusual for a homeowner with little experience in sanding to wind up with sanding discrepancies; this refers to uneven areas where sanding is deeper in one spot than another or where swirl marks and scratches appear. In some cases, you may even cause dents and divots when you sand a floor yourself. Paint and stain don't typically cover these discrepancies, especially when they're very deep and obvious. A professional will ensure a smooth and even floor surface that is ready to hold paint or varnish, or the coating of your choice.
Sanding too much
Even solid hardwood floor slats are only so thick so that they will eventually be too thin to sand again and would then need to be replaced. A common mistake homeowners make when sanding their floors is apply too much pressure or to use a sandpaper that cuts too far through the surface, and they remove more of the wood than necessary. In turn, you may need to replace your wood floors sooner than you should and more often over the years. Thin floors may also be too weak to support heavy furniture and foot traffic, which can lead to cracking and shifting, and they would then need replacing. Consider that the cost of hiring a professional is actually more economical in the long run, and leave this work to them.