It's not a common question since paint sprayers are far more available than ever before. Commercial-grade high-velocity paint sprayers can be rented for $400 to $600 per week and consumer-grade sprayers can be purchased for half of that amount.
Not only that, paint-brushing might seem like a time-consuming activity best confined to smaller areas like window trim or doors. Yet when the conditions are right, brushing your house's next color coat does make some sense.
Quick to start
Attention to details
Less prep work
Much prep work
Faster (once painting begins)
More wasted paint
Covers details well
Using a Brush vs. Sprayer For Painting a House Exterior
Using a paintbrush to paint your house lets you get started faster each day. You don't have so many tools and materials that need to be brought out and set up. Often, you can break up the brushing into several smaller projects throughout the day.
Considerably less covering and masking of clean areas are required. Spraying requires a wide buffer of plastic sheeting or dropcloth. By contrast, brushing needs only a dropcloth for the area directly below the paint area.
When brushing, you'll have the chance to pay more attention to the details. If there is a problem area that needs fixing, you'll often see it better when brushing rather than when spraying.
Brushing, too, is a great way to conserve paint. The paint goes on thicker when brushing, yet it uses less paint.
Still, brushing is more physically demanding than spraying. You'll need to be able to reach all areas of the house exterior, even the highest spots.
Using a paint sprayer for your home's exterior means that you can cover more areas faster–but only after the prep work is done. Difficult architectural work and textures are easy to cover with a paint sprayer. Sprayers can extend your reach by another couple of feet when you have high or out-of-the-way areas.
With spraying, you'll need to cover obstructions from utilities (wires, pipes, gas meters), architectural details, plants, driveways, sidewalks, and anything else that will not be painted. Once you have everything masked and taped-up, spraying is faster than brushing.
This can be a tough, multi-day job: a project all by itself. Also, the weather can interfere. You'll need to be aware of upcoming rain since it can ruin your coverage work.
How Much Paint to Use
Brushing the Paint
In general, you will use up to three times more paint by spraying than by brushing–plus, you risk getting a thinner coat.
One gallon of exterior acrylic-latex on a clean, painted or primed surface–a minimum of porosity–is estimated by manufacturers to cover about 400 square feet.
Dripping and laying on the paint too thick are factors that will lower this estimate.
Spraying the Paint
Spraying uses more paint because the sprayer atomizes the paint into tiny droplets. Most of the droplets end up on the surface, but many others drift away. This is inherent with paint spraying, and little can be done to control it.
Also, paint left in the hose must be blown out. Some of the paint can be saved, but much of it goes to waste.
One gallon of paint will cover about 150 to 200 square feet of wall. We would be more careful and even estimate more like a 1:3 ratio (1 gallon brushed on will require 3 gallons when sprayed on).
How to Conserve Paint When Spraying
Avoid the Wind
Even a mild, 5 mph wind is enough to blow away sprayed paint. Very windy days can increase your paint consumption by as much as 50-percent. It's difficult to block the paint, so wait until conditions are better before spraying again.
Pump the Paint Back
When you are finished, it might be tempting to spray out the rest of the paint into the air. Instead, pump the paint remaining in the hose back into the container instead of disposing of it. Paint remaining in even 25 feet of the hose can add up. Plus, conserving the paint is more eco-friendly.
Stand Closer to the Surface
The farther away from the surface you are, the more paint drifts away as a cloud. Standing closer to the surface reduces this paint-cloud.
But be careful. Spraying closer means a greater chance of drips. Also, you get more blow-back from the sprayer, which means suiting up with a paint sock over your head, coveralls, respirator, and tight goggles.