There are three principal layers; 1  External intercostal muscles aid in quiet and forced inhalation. They originate on ribs 1-11 and have their insertion on ribs 2-12. 2  Internal intercostal muscles aid in forced expiration (quiet expiration is a passive process).
Costs. A professional concrete contractor will typically charge $2-$4 per square foot for a simple stain application, including the sealer. A stain application with patterning and sawed lines will typically cost between $4 and $10 per square foot.
BASIC COST. $2 - $6 per square foot A single stain color on existing concrete MID-RANGE COST. $7 - $14 per square foot Saw cuts, multiple colors, polishing or overlay HIGH-END COST. $15 - $30 per square foot Embeds, divider strips, stencils, epoxy terrazzo