Surely no sensible person would wear a shirt and tie :

Smart cargo trousers and a polo shirt with company logo is about right i think!
Do customers really want to see you trussed up in shirt and tie on a hot day, sweating etc, i not think so.
The clothing has to relate to the job, and we do a manual job, theres no two ways anout it.
If i go canvassing or doing quotes then often i will wear a shirt and tie, but the fact is, if you look smart and have id then that should be good enough.
If i had a builder or plumber turn up with shirt and tie on i would laugh my head off and assume they weren't going to get there hands dirty!

regards
steve