Help with creating VBA to filter validation list

Hi, I'm new here and found my way through a Google search.

I know very little about programming using VBA in Excel. I am currently using Excel 2007 at home and work. I am working on a spreadsheet but I'm trying to automatically filter information based on the input in the validation list.

I have attached an Excel file that I am working on. I was able to search and find a similar issue/resolution to my issue. Found here:
http://excel.bigresource.com/Track/excel-5DHphNL2/

Unfortunately, I can't figure out how to make it work for my particular application. I have validation lists next to the cells that are highlighted in yellow.

I would like for the "Joist Size" list to hide certain rows in 13-101 based on the matching formula result down column B.

Ex:
If I choose 8 in the validation list next to "Joist Size", then a formula next to the 8" joists will display 8. I would like the macro to hide any rows from 13-101 that do not contain 8. Of course, All would display all values and other numbers would filter my rows.

"LL Deflection Ratio" & "Spacing" would hide columns based on the choice in the list.

Any help would be greatly appreciated!

TIA

Evan