How best to remove fumes after applying polyurethane in a hardwood refinishing project?

Question

I understand that oil based polyurethane used to refinish hardwood floors has a strong fumes and can stay for days. I also understand that opening the doors and letting air flow can help remove the odor faster. I also have been told that moisture is not good for the oil based polyurethane curing process.

Question: What is the tried and proven method to speedily remove the odor with out affecting the oil based polyurethane curing process?

Assumed weather conditions in a 5 day period

• Temperature: Low of 25F (Approx) and High of 45F (Approx)
• Conditions: Partly cloudy, Sunny and Mostly Sunny
• Humidity: Low of 44% and High of 70%

I have been told to keeping the temperature at 71F for few days will help cure the oil based polyurethane best.

References:

• When is it safe to live in our home?
• How long does it take polyurethane to dry?

Answer 1

Turn up the heat while opening windows across the house. Put in fans in windows/doors blowing in the house on one or two sides. Just don't put fans blowing in all windows so air has an easier chance of escaping. It would be better to open all windows partially than two windows fully.

Definitely make sure you have at least one fan though to create a pressure differential to push out the inside air. As an example, we have used 6 box fans with filtered air on the intake fans sealed to an opening while lacquering cabinets (extremely high fumes) and it kept the fumes down to a minimum throughout the rest of the house DURING spraying. You have less fumes so even a couple fans could do a world of difference.

Consider the heat a cost of doing the project. Might cost $100-$200 in heat over 5 days if you really opened things up but should be less. Just depends on how long, heating method, fuel cost, and how much you change out the air.

You could also purge the house at intervals by doing this for 1-2+ hours or so at a time 1+ time a day until you are satisfied with the fume level.

You might need to re-purge even weeks later if your house is really sealed up and you are concerned about the fumes.

Answer 2

Timeframe

The floor should be mostly cured (enough to live on) in the first 5-7 days, but it can take up to a month for the odors to be completely gone, and for the finish to reach its maximum hardness.

Solutions

For the first few days, "airing out" the house should be a priority. This is difficult during the winter months, but keeping air moving is important. Make sure you keep a window at least part way open in every room, and setting up fans will help keep the air moving. This can get expensive while keeping the temperature up.

Alternatively, if you aren't living in the house, you can concentrate on keeping the temperature up and humidity low, with only minimal air exchange. Two open windows on opposite sides of the living area should be fine. The fumes are unpleasant, but aren't flammable. After letting the finish cure, then you can focus on evacuating the air. Airing out the house at this point for 1 or 2 days should remove enough of the fumes to be safe, but it's a good idea to keep your house at negative pressure for a few weeks, especially if you have sensitive pets/children/seniors.

By negative pressure, I mean making sure there is active removal of air from the house. A couple of fans in upstairs windows will do nicely, or at one end of the house if single-level. This is more important than bringing fresh air in. If your home is brand new, you may need to set up a fan and window to source fresh air, but older homes will generally leak enough to make up the difference fine. You should also leave all your doors open, letting the air circulate.

Water-based options

Depending on where you are in the process of refinishing, you may want to look into some of the new water-based polyurethane options. They have advanced quite a lot in the last few years, and some are starting to rival oil-based for durability, with a fraction of the fumes. This would require more research on your part, but if you are concerned with the smell, it may be an option.