As winter quickly approaches in Denver, the majority of painting will be done inside where interior decorating becomes the Thing to Do. While we discussed in a recent post Interior Painting-Commercial/Industrial the formula estimating square footage areas for ceilings containing B-Decking and Bar Joist supports, another formula comes to mind when we are speaking of interior painting of the residential home. This formula works just about every time, re-checking long-hand, so I feel comfortable with my calculations, not needing to spend 3 times as long on a 10 key or hand held calculator adding up each and every nook and cranny floor sq. ft. then figuring walls and ceilings for gallons needed.
First lets say we are figuring a 10' X 10' room w/8' ceilings.
8' tall walls would be 4 X 8' X 10' = 320 & + 10' X 10' = 420 sq. ft. of surface area including ceiling
9' tall walls would be 4 X 9' X 10' = 360 &+ 10' X 10' = 460 sq. ft. of surface area including ceiling
10' tall walls would be 4 X 10' X 10' = 400 & + 10' X 10' = 500 sq. ft. of surface area including ceiling
12' tall walls would be 4 X 12' X 10' = 480 & + 10' X 10' = 580 sq. ft. of surface area including ceiling
Now we agree on this, this is where the fun begins. Using a little arithmetic you may or may not have learned in school, although I'm sure it was taught if you attended a school in America.
A typical modest interior home is an average 2000 sq. ft. of floor space. Using this as an example, you'll want to move the decimal over 2 places to the right, multiplying total square footage of floor, giving you almost an exact surface square footage of total painted surface square footage!
2000 X 4.2 = 8400 X (price per sq. ft) = Interior Painting Job
2000 X 4.6 = 9200 X (p.p.sq.ft) = Interior Painting Job
Knowing full well extra interior painting costs are involved painting ceilings one color, walls another, and extra charges for multiple colors throughout, these extras do not account with this equation, but can be implemented with p.p.sq.ft. We've seen interior painting estimates vary greatly, some I wonder if they are indeed painters at all, charging so much, typically referred in the painting industry of Colorado as Hobo Painters, having only the ability to swing a brush.
These total sq. ft. figures is also helpful giving a basis to calculate gallons needed, using a neutral tint base covers approx. 250 sq. ft of surface for textured walls and ceilings. Deep tint based colors may only cover 80-100 sq. ft. of surface, having to apply multiple coats for uniform finish.