Freddy, when you're looking a for a specific post the internal search engine is usually the best:
http://nepacrossroads.com/search.phpYou can greatly narrow down the results to things like which forum it was posted it, author etc.
You can access that search page by clicking the little magnifying glass next to the font resizer icon.
For example this lists all results for underground in the Venting plumbing and heating section.