Installing New Hardwood Over Old Hardwood Floors
Installing new hardwood over older wood floors can be extremely time saving in lieu of removal that can become expensive, dirty, and even dangerous depending on how the original floor was installed.
For instance, I will look at much older floors that were nailed into floor joists before the widespread use of subfloors. Removing can become dangerous as there’s no room to work from once floorboards are taken up. It becomes a tightrope scenario, trying to balance from one area to another unless some temporary platforms are put into place.
Easy Way Out May Not Be The Best Method
By simply nailing over an older floor, don’t expect old squeaks to go way. If they were there before starting the job, make sure permanent fixes are put into use. Often older flooring loosens from the floor joists or the sub floor. Common decking screws or ring shank nails can be used to shore up some squeaks. For more intense problems it may be wise to call in a structural engineer. Older homes without modern foundations often settle severely.
Newly fastened floors over existing wood floors should be installed opposite (example photo right) or at a 45 degree angle to the original direction. If you’re dead set on keeping the original direction, a minimum 3/8 plywood sub floor should be installed over the older floor.
Can I Install New Hardwood Over A Floating Floor?
Sorry, the answer is no. The older floating floor has too much flex for another floating floor or an attached floor with nails or staples. Besides floating systems are the easiest to remove, but some care should be used when removing from under door casings and the like.
Installing A New Gluedown Floor
We get opposing views on this one, but most professionals feel more secure by complete removal and then installing a new floor. There can be too many unknowns in so far as the bond between the older floor and the underlying adhesive. In years to come newer adhesives may be stronger than what is being used today. What may happen is the new actually pulling the older floor from what was thought to be a permanent bond.
Easier solutions with installing over old glued floors would be floating floors. With all types of new over old, expect transitions to other floor coverings to be an issue. Additionally, the newer floor height may require changes in baseboard height or alterations to doors, cabinets, and appliances.
Parquet Flooring
Although parquet is no longer as popular as it once was, a few precautions should be considered specifically with those products that are installed using Polyvinyl Acetate (PVA) adhesives with vinyl or cork flooring requiring an additional underlayment. Additionally, any parquet flooring patterns installed over existing strip or plank flooring should also have a minimum 3/8” underlayment added.
Special Note:
In some cases older nailed flooring may have been installed before walls were in place. Removal would require cutting around the perimeter of each room up to the wall area. Today, a nifty tool called the toe kick saw makes removal a much easier task. For other types of installations, expect the floors to be installed with expansion in mind. In other words, floors will not be installed under, with possible exceptions of built in wall cabinets and the like.