Overcoating vs Full Sand
A full resand costs $60-110 per square metre and takes 3-5 days. An overcoat costs $25-40 per square metre and takes 1 day. The catch: overcoating only works if the conditions are right.
When Overcoating Works
- Existing coating is intact but worn thin in traffic areas
- Surface has fine scratches and scuffs but no peeling or flaking
- You want to change the sheen level
- The existing finish is water-based polyurethane in reasonable condition
- There are no deep scratches, stains, or discolouration that need sanding out
When You Need a Full Resand
- Coating is peeling, flaking, or delaminating
- Deep scratches or gouges in the timber
- Water damage or black staining
- You want to change the colour (stain)
- The floor has been waxed or treated with silicone-based products
- The existing finish is unknown and adhesion testing fails
- Boards are cupped, crowned, or uneven
- You want to remove old solvent coating and switch to water-based
The Overcoat Process
- Clean: Thorough clean with Bona Prep to remove all contaminants
- Abrade: Screen the entire floor with 120-150 grit mesh to create mechanical adhesion. This is NOT sanding back to timber — just scuffing the surface
- Vacuum: Remove all dust with HEPA vacuum
- Coat: Apply 1-2 coats of Bona Traffic HD, Mega, or Wave 2K
- Cure: Same cure times as a new floor
The Adhesion Test
Before overcoating, a contractor should perform a cross-hatch adhesion test. Score a small grid into the existing coating with a blade, apply tape, and pull. If the coating comes away with the tape, overcoating will fail — the new coat will bond to the old coat which is not bonded to the timber. Full resand is the only fix.
Frequently Asked Questions
Can timber stairs be sanded and recoated?
Yes, FSA Network floor sanders use the Bona Edge UX and hand-sanding techniques to sand and recoat timber stairs, then apply Bona Traffic HD Anti-Slip for maximum durability and safety. Stairs can be restored to look like new. Book at floorsandingaustralia.com.
Do I need primer if my floor is being recoated?
For a maintenance recoat where the existing finish is still in good condition, primer is not usually needed -- the floor is screened and recoated directly. For a full sand back to bare timber, primer is essential. FSA Network floor sanders assess which approach your floor needs. Assessment at floorsandingaustralia.com.
What is a maintenance recoat?
A maintenance recoat involves lightly screening the existing finish with the Bona FlexiSand 1.9, then applying a fresh topcoat without fully sanding the floor back to bare timber. FSA Network floor sanders offer this as a cost-effective way to refresh your floor's protection. Recoat details at floorsandingaustralia.com.
When does my floor need a recoat vs a full sand?
If the finish is worn but the timber underneath is not damaged, a maintenance recoat is sufficient. If the timber itself is scratched, stained, or uneven, a full sand is needed. FSA Network floor sanders assess your floor and recommend the most cost-effective option. Assessment at floorsandingaustralia.com.
Can floor cleaners affect the ability to recoat my floor later?
Yes, some cleaners leave films on the floor surface that compromise recoatability, meaning future coats may not adhere properly. Consider stripping and rinsing the floor before recoating if unknown cleaners have been used. FSA Network floor sanders always assess existing floor surfaces for contaminants before recoating.