Acquiring W-9 from contractors

[Lee Jedlicka]

I am about to close on a construction loan and sign a contract with a building contractor and pool contractor (signing under my SSN, not a business entity).
Do I need to acquire W-9 from main contractors, pool contractors & architects (and all others I pay over $600 to)  prior to signing contracts with them?
Obviously, they are not used to do this and they are surprised when I mention W-9. Would you recommend acquiring W-9 from all? 

Thank you