Can anyone tell me what this chart (specific column) is expressing?

I’m currently taking the ‘How to Inspect for Moisture Intrusion Course’, and have a question pertaining to ‘Section 2.3’ (moisture-Resistant Wall systems). In this module listed under ‘STEP 2: ASSESS BUILDING EXPOSURE’ there is a chart labeled 'Table 7 - Building Exposure Levels’, which I’ve attached. My question is: how do you read the ‘Overhang Ratio’ column - what is it expressing specifically?!
Any help would be appreciated!

It’s a ratio of wall height to overhang length. Example, an 8’ high wall with a 2’ overhang would be a 0.25 overhang ratio. 2’ is 0.25 percent of 8’. 4’ overhang would be 0.5, 6’ would be 0.75, etc.

The over hang ratio is the ratio of the width of the overhang to the height of the wall. So a 8’ wall with a 4’ overhang has a ratio of .5 . 8’ wall with a overhang of 2’ has a ratio of .25. Think of it as a percentage of the height so for a 8’ wall 4’ overhang is 50% or .50 and 2’ overhang is 25% of 8’ so it would be .25. The way you calculate this is divide the width of the overhang by the height of the wall so 2/8=.25 4/8=.5 or a ten foot wall with a 18" overhang is 1.5’/10’=.15 or 18"/120"=.15 . I hope this helps.


That you for the explanation - makes much more sense now.

Best Regards


Thank you - I appreciate it!

I’ve been in this course for a month. Every time I read it ZzZzZzZzzzz after like 10 minutes. It’s a great course, but at the end of the day man oh man is it good for sleeping.