VOC stands for ‘Volatile Organic Compounds’. I could give you the fancy scientific definition but for our purposes regarding your floors let’s keep it simple. It is the off gassing that occurs from chemicals that are applied as protective coatings to floors. The smell to put it very simply. It is measured in grams per liter or g/l . You can find out more about VOC’s and other air quality issues here: https://www.epa.gov/indoor-air-quality-iaq
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.
Ann Arbor Hardwoods prefers to use water based finish, specifically Pallman, and Bona products.
Dustless is not the same as dust free, you can expect to see a small amount of dust on horizontal surfaces in the immediate areas being sanded, it will be limited to that area and not throughout the whole house. The dust will not build up on walls and other vertical surfaces. Also to put things into perspective a typical 500 sq ft room refinish would yield about 30-40 gallons of saw dust through the entire sanding process. The dustless system Ann Arbor Hardwoods uses will take care of 99.9% of the dust created. The system is a Diamond Jet 1200 dustless system which is manufactured specifically for hardwood sanding. The System is H.E.P.A. certified and is certified for lead safe paint removal.