This question has a lot of answers so I will list the pros and cons of each. Let’s start with Polyurethane or OMU pros.
- Tried and tested, an industry standard for over 65 years.
- Cost, most commercially available floor polyurethane is around $15-$20 a gallon
- Has a thick build more solids than water based finishes
- Has an amber tint also called “grain enhancing”
- VOC’s the average floor grade polyurethane has about 550 g/l even new VOC compliant poly’s are at 450 g/l. “you should not be in the house”
- Dry times depending on the current humidity and temperature I have seen polyurethane take 3 days to dry before another coat could be applied. Minimum of 12 hours
- Color change over time to orange, I placed this in the cons due to the fact that color matching a repair to aged poly is extremely difficult and the repair will not change with the rest of the floor.
- Can contain lead drying agents pre 1978
Water based Pros
- Low VOC content typically around 225g/l-150g/l very light sent
- Dry times dries to the touch in an hour fully cured in 3-10 days
- Is harder than polyurethane
- Multiple coats can be applied in one day
- Has a true clear finish but can have an ambering sealer added to replicate grain enhancement of poly.
- Much less color change then poly over time
- No lead content at all
Water based Cons
- Cost water based finish is 3-4 times more expensive then poly around $60-$120 a gallon
- Less solids “thinner build” need at least 3 coats
- Only been used commercially for 15ish years
- Most contractors are resistant to change so not as commonly used in the industry and has a different skill set to apply.