Many people get puzzled why they need to lay a sub floor before the hardwood floors itself. It will just cost them more money and more pain in installing wood flooring, and can it be directly installed over the existing floor material since hardwood floors had been brag so many times of being durable and reliable over the years.
Well actually the answer is very simple; if you do not have wood flooring as an existing material then you will need to lay a sub floor since it has to be nailed down in place. The sub layer will also ensure that the planks are arrange properly and is tightly shut to prevent disarrangement and unwanted gaps over time.
Another question that will probably pop out of your mind is what materials should be used as a sub layer. Well then, here are the most common materials.
CDX grade plywood CDX is a type of high grade plywood, The C meaning to say one side is graded as C and D mean the other is graded as D. The X stands for the glue which is an exterior one but it does not mean that CDX is exterior plywood. This type of plywood is perfect as a sub layer, though it is not generally tough that of the exterior grade, it has a characteristic to resist moisture better compared to others prolonging the life span of your hardwood floors.
OSB PS2 rated under laymen This type of under laymen is very stiff and flat providing you a better work space and ensuring that the wood planks will be laid perfectly and will not affect the depth and thickness of each plank. The characteristic of the material also ensure to reduce any squeaking and crunching sound when you have the project done.
Existing wood flooring If you existing wood floors then it can serve as a sub layer just make sure that you sand it down for a flat finish and patch gaps and dents if possible to prevent squeaking and stabilize the foundation of the new planks.
Screeds Screeds or commonly known as sleepers are pressure treated boards, the material is a common alternative for CDX plywood because of the durability that offers and the stabilization that it brings.
The sub layer is as important as the durability of the hardwood floor itself, it serves as the foundation of the flooring ensuring the strength and reliability of the material. If installed properly you can definitely achieve the outcome that youve always wanted