[boblenzen]

Dryfall vs. failed flooring? See photos

Oil based dry fall cause concrete floors to stain?
I am doing a large retail store and the job was speced out for oil based dryfall from Sherwin Williams. 60% of entire corrugated steel ceiling deck was sprayed while the floor was dirt. At that point the GC asked us to work on the outside only so that the colored concrete floor could be poured. We were not allowed to return for about two weeks. We then continued spraying the ceiling deck. They have been installing addtional conduit piping that we had to go back and spray. During this process it rained a couple of days and since the ceiling was not sealed yet there was some leakage onto the floor. The paint dust (dryfall) that was on the floor and in some areas did get damp. The damage to the floor is throughout the entire building. I have hired a cleaning company who uses very powerful machinery to clean the floor surfaces and they have been unable to remove it from the surface. The stains appear to be much deeper than just on the surface. The whole reason that Dryfall is used is because it dries before it hits the ground. I have sent samples to the Sherwin Williams lab. Has anyone else ever seen this before.

Bob Lenzen

 

[paintpimp]

Here is a theory, it doesnt account for all the staining you have shown on the pictures. Dryfall will fall dry. But it is still droplets of paint. It is not cured yet. Dryfalls can vary from 7-14 days complete cure. Now you have oil droplets of paint that landed into damp areas with no chance to cure. If yourself or other trades walked or drove over these puddles and broke open these tiny spheres of uncured paint they could re-wet and stain the floor. The first picture you have doesn't support this theory as well, but the others do. It looks like their are tracks through the stains. When you apply dryfall, ALWAYS use tarps if someone will be driving over the top of the dryfall before its swept up.

 

[boblenzen]

Thanks for your reply. My paint rep and I discussed the same scenario. The dryfall was sprayed indoors during very dry 115 degree days and the ceilings is 30 feet high. There are some track marks on the floor as well from lifts being driven over it. The problem with masking off the floor is that we are talking about an open floor of 180,000 square feet and every trade imagineable working on the floor during this process. I understand that the dryfall could adhere to the surface of the newly installed flooring. However, I would expect that laquar thinner, goof off or the high powered floor cleaning machinary that we are using would be able to remove it from the surface. It appears that most of it is below the surface. My theory at this point is that maybe the floor sealer had not cured and absorbed the dryall below the surface. What do you suggest when applying dryfall to that large of a surface. It would take hundreds of drop cloths and they would be tangled up everywhere. Thanks for your assistance.

 

[Tmrrptr]

Lacquer thinner definitely works great to remove paint residue.

If someone were to apply it over a large area they would be building a BOMB.

Just over a year ago a local painter was blown out through the front wall of a house and landed at the curb while spraying lacquer on cabinets.
He was, up to that point, unaware of the water heater pilot light.

No need to tarp 180k sqft... you can only spray a portion at a time, anyway. Hang a large plastic drape, down from one side of your work area, and allow it to also go over floor in that area... big L shape.
Ventilate to outside. Should not have other trades in spray area where respirator should be worn, anyway. Drape may help keep them out.
r