Decision guide
Nail-down, glue-down or floating
Which hardwood installation method is correct for my subfloor?
Installation method is not a preference and not a sales option. It is determined by the substrate, the product construction, and the climate load the floor will face for decades.
First
What actually decides this
What the floor is going onto
Plywood accepts fasteners. Concrete does not. Radiant assemblies constrain both fastening and adhesive choice.
Product construction
Solid and engineered do not accept the same methods. The construction and the substrate must agree before a method is chosen.
Acoustic requirements
Condominium boards commonly impose sound-transmission requirements that the assembly, not the flooring, has to satisfy.
Reference
Comparison
| Method | When it is correct |
|---|---|
| Nail-down | Solid hardwood over plywood |
| Glue-down | Engineered over concrete, or in condominiums |
| Floating | Engineered over radiant, or where acoustic separation is required |
Decide
The decision tree, in the order we walk it
- Plywood over joists, solid product → nail-down.
- Concrete slab or condominium, engineered product → glue-down.
- Radiant heat, or an acoustic separation requirement → floating.
- Any combination not on this list → the substrate or the product is wrong, not the method.
Answer
What we recommend
Match the method to the substrate and the product construction, in that order. A method chosen before the substrate has been identified is a guess with a delay built into it.
- If a contractor proposes a method without naming your substrate, that is criterion 2.1 of the framework failing.
Provenance
Where every claim on this page comes from
- Climate Mastery — method and substrate
- The Intelligent Homeowner's Decision Framework — decision tree