'in two rooms" meaning two outside walls, or are you looking for some kind of interior (heat or sound) insulation?

we had spray foam in an exterior wall that was pretty clearly underinsulated (leading to a constantly chilly dining room) and it definitely helped. didn't fix the problem, but made it much more bearable.

Thankyou for your response, yes it is for two exterior walls. I was concerned about a smell afterwards, ive read cases where people have had spray foam and they were bothered by the smell. Do you know if your application was open or closed cell. Thankyou.

don't recall. we didn't have any smell, but they did leave us a bunch of round plugs in the wall where they stuck in their hoses, and we had to repair and repaint on our own. whee.

Spray foam is made with isocyanates that are reacted with polyols. The reaction will outgas while it is occurring, so it is generally recommended one stay out of the house during this "curing" time and not disturb the foam, so as to not release unreacted ingredients. Once this reaction takes place completely, neither of its reactants should remain (remember Chemistry?), just the product foam, which is generally deemed to be inert. The smell would generally indicate continued outgassing, which might indicate an incomplete reaction, or it could be something else. No smell would seem to imply the reaction being complete, or lack of sensitivity to the chemical(s) and their odors.

Here's the EPA's article about it:

https://www.epa.gov/saferchoice/potential-chemical-exposures-spray-polyurethane-foam#curing

The curing and curing rates sections cover most of what I mentioned.

This is not meant to be for or against spray foam, but since you asked for things you should be aware of and inquired about bothersome smell, I thought it might be of interest.

We have used nothing but spray foam insulation in our projects for several years now. Much better insulation per inch than fibreglass or rock wool, and it fills cavities, crevices and gaps around plumbing and wiring vastly better than hand-cut batt insulation. Some of my clients are careful trackers of their energy costs and all have seen considerable energy savings (albeit these are projects where the entire house was spray foamed, not just a wall or two).

My spray foam was installed back in 2009 or so. The contractor I used sprayed either open or closed cell. For wood frame residences like I had, he recommended open cell because it would flex with the framing lumber due to seasonal changes and wouldn't detach from the lumber like closed cell could. He said typically he only used closed cell on commercial steel frame buildings. Anyway, since he was capable of doing either, I trusted him and went with open cell. I've had no problems.

My walls were open so all spraying done on the interior. He used a soy based product. I don't remember the blowing agent used but I don't recall any lingering smells post install. One big unexpected benefit, spray foam is an excellent sound barrier.

I really appreciate the feed back, thankyou. My biggest concern was having the sprayfoam inbehind the dirent vent gas fireplace. The contractor i had encouraged me to get this as these chases always seem to never be insulated properly by the builder. My builder used the pink fibreglass and it did nothing to stop any air leakages there would always be a really cold draft in front of the gas fireplace. So sprayfoam he said was the way to go and to do the same wall in the sprayfoam also while he was doing.

Regarding the spray foam and the direct vent gas fireplace . . . . I'd contact the fireplace manufacturer to determine what the combustible clearances need to be.