I consult for a construction and real estate company. In addition to using Ziprecruiter the company also uses Craigslist to post positions and have been pretty successful.  Also, the cost to post positions on Craigslist is not as expensive as other sites. 

Ericka we had a similar role a few years ago and it is VERY hard and the market wasn't as tight then as it is now. We tried really different approaches than the traditional postings. Create a flier that you can try posting at HomeDepot and Lowe's where these folks may go to get supplies. We even handed the fliers out to "crew" we saw doing a roof (commercial or residential). We just kept trying to brainstorm where these folks may be that we can spread the word. If you want to brainstorm more, just drop me an email (Robin@strategicHRinc.com)