It is with all of these things in mind that we have decided to show you what we think are the ten best non-comedogenic foundations. Somewhere in our top ten picks is a foundation that will work perfectly for you and your exact skin type-along with all of the problems that may go with it.
SPAN/LOADING NOTES. Deflection limited to L/360 live load & L/240 total load. Spans based upon a stair limits of 8 max rise and 9 min. run, governing building codes may be more restrictive. Contact National Lumber EWP Engineering for design. assistance on other stair stringer applications and/or loading.
For the example staircase, take the total rise of 102 inches divided by 13 risers to equal 7.85 inches, rounded to 7 7/8 inches for each riser. Next calculate the run of the staircase to find the stringer length. Multiply the 12 treads by the minimum tread depth of 9 inches to arrive at 108 inches for the staircase run.