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.
Installation of ceramic tile costs between $11 and $22 per square foot, according to the website Concrete Network. Natural stone tiles cost between $20 and $50 per square foot. Staining an existing concrete slab can cost $2 to $15 per foot. However, if a concrete slab must be installed, or the staining processes included multiple stains, stamping or scoring, the cost can quickly double or even triple.