Good tips!
We try to get our clients as close as possible to the correct amount of material that's needed for the job, and seldom are we off much. We spec different amounts for 300 - 400 ft2; 401 - 500 ft2, etc. All of them have a 10% waste factored in, so as long as that's not exceeded, and the material is spread somewhat evenly, the finished system will be within specs.
By the way, this is all straight forward math. 1 Gallon of ANY paint (or even ANY liquid) will cover 1604 square feet at 1 mil thickness wet. That means, if you spread ONE gallon of water on a surface at 1 mil thick you would cover 1604 square feet. If you spread one gallon of paint at one mil on the same surface you will cover... 1604 square feet. What if you spread honey, Jack Daniels, Milk, or even urine at 1 mil thickness? You guessed it... 1604 square feet!
So if you're dealing with a 100% solids coating, and you know the recommended minimum dry film thickness and the square footage of the area to be coated, it's simple to determine the amount of material required.
For example, coating a 1,000 ft2 floor with LiquaTile. With LiquaTile 1184 to get the best value and performance for residential and small shop floors it needs to be applied at a depth of 12 mils thick. So for 1,000 ft2 you would need 1,000 * 12, or 12,000 mils. It’s impossible to use every last drop, or mil, in the can, so the industry standard is to add in a 10% – 15% waste factor, we use 10%, so 12,000 + 10% = 13,440.
As noted earlier a gallon of liquid, any liquid, will cover 1,604 ft2 to a depth of 1 mil, in other words a gallon has 1,604 mils in it. So your project needs 13,440 mils of LiquaTile 1184, 13,440/ 1,604 = 8.379 gallons required. The closest we have to that amount would be three 3 gallon kits, or 9 gallons. Without waste that would give you 14.436 mils/ft2; and minus 10% waste you should have 12.99 mils when fully cured.
About moisture... Different products will react differently here. Our primer, BondTite 1101, can actually be applied to concrete that's not "bone dry," we say it can go on "damp", but not "moist," concrete. That is no standing water, and you should see some parts of the floor lightening up. But depending on climate it can take longer to cure, but not much more than if it were bone dry.
Those marks can be tough to remove. I place a large piece of cardboard adjacent to the work area to step onto and remove spikes etc.
A few other tips...
-Only have the cans for the materials immediately required in the mixing area. If you're doing the primer coat, have only primer components out, stash the body and clear coat materials where they can't accidentally be opened and mixed.
-If you're coating underneath the garage door figure out in advance how to close the door without allowing it to close all the way and stick to the coating (on automatic doors I place Visegrips on the tracks to stop the door at a predetermined position).
-Practice broadcasting flakes beforehand. And remember that it's easy to apply more flakes, but if you put down too many you can't lift 'em up, so use small hand fulls.
-Have some MEK or denatured alcohol standing by in case of spills. MEK is stronger, but a bit nastier to work with. I usually opt for denatured alcohol.
-Thoroughly mixing the components is key!!!!
-After you've mixed the components, do not scrape out the mixing container in order to get the last drop, odds are there's a bit of unmixed material on the sides or bottom of the mixing container, if they get on the floor you will end up with spots that will be soft and never cure.
-Pay attention to any weather restrictions. If it says "Don't apply in *** weather," then do not apply in *** weather.
-Read the instructions, avoid short cuts, relax and take your time, and enjoy the process and the results!