The smell
Does a floor coating smell?
There is an odor while the material goes down and while it cures, and how strong it is depends on the product and on how much air moves through the room.
The short version
- There is an odor during the install and while the coating cures.
- How much there is depends on the product and on the ventilation in the room.
- An attached garage shares air with the house through the door between them.
- The manufacturer's label is the authority on handling and on ventilation for that exact product.
- Ask the installer what is going down in your room and what he does about air movement.
What you smell and when
There is a smell while the material goes down and there is a smell while it cures, and they are not the same smell. It is heaviest during the install itself, when the material is open and getting spread across the floor. It backs off as the coating hardens, and it keeps backing off after the floor looks finished.
How much there is depends on what is going down and on how much air is moving through the room. Products differ from each other a great deal on this. The same material in an open garage with the overhead door up is a different experience from that material in a closed basement.
An attached garage and a finished basement
An attached garage shares air with the house. The door between them is not sealed, the house is usually pulling air in from somewhere, and that somewhere is often the garage. So a garage install can be noticeable inside the house even with the overhead door standing wide open.
A basement is the harder room, because it has no big opening in it and the air does not turn over on its own. What normally gets arranged there is mechanical: fans moving air, a path for it to go out, and whatever windows and doors the room has standing open.
If somebody in the house is sensitive to smells, or there is a reason a person would rather be out of the building while the work is going on, that is a conversation to have with the installer beforehand rather than that morning, because it changes how the room gets aired out.
The label is the authority
Every coating comes with a manufacturer's label, and that label is the authority on handling the product and on what ventilation it calls for. It is not a formality. It is written by the people who made the material, it is specific to that material, and it is the document anybody working with the stuff goes by.
So ask. Ask what is going into your room, ask what its label says about ventilation, and ask what the installer does about air movement while the floor goes in and while it cures. Hearing the plan out loud before the work starts is a reasonable thing to want.