Between the more extensive prep work required when spraying, the time it takes to properly clean and care for the sprayer before and after each time you use it, the learning curve for good application technique, the mess and headache if it doesn’t work right, it just seems like a lot of trouble for painting interior walls. But it doesn’t mean all work cannot be done faster. How To Paint an Interior Room with a Paint Sprayer Paint spraying wastes an incredible amount of paint when the atomized paint drifts away. How long does it take to paint a house interior with a sprayer . At the same time, high end custom work much more time consuming process and will take longer to complete. Spray paint applies thin and evenly which makes it dry to the touch in as little as 30 minutes and ready for another coat in as little as one hour—even for glossy paint. Masking was simple because of this and being able to do the entire house in about 8 hours of work over two days paid for the extra paint a...