First off, are you having adults at the party?  If so veggies and dip or chips and salsa are a good standard served in a tool box (lined with wax paper or bandanas).  In my experience (my daughter is 7 now) a party at 3:00 pm people are happy with snack food and the kids just want cake and ice cream.  The thing to key in on is how things are served.  Be creative go to the hardware store to look for containers.  A hard hat can be used for serving ice or stick florist foam in and do fruit on skewers to stick in the foam.

If you are using balloons for decorations, use tools to weight  them down (hammers etc).

Hope this helps.  Feel free to email me at ******************** if you need some more ideas.  I love planning themed birthday parties.  Also go to the library, there are sections on themed party planning and should give you some great food ideas.  Keep it simple as possible. 

Julie

Simple is better and food that is served cold or room temperature and self-service is easiest.  For adults, a sandwich platter or giant hoagy would be cute.  For kids, you could do a platter of pb&j cut into quarters. Self-service contained beverages in a small size (juice boxes, small water bottles and 100 calorie sodas) are the best size for kids and adults.

I LOVE this theme, jeanab1299. What a fantastic idea. Hopefully, I haven't missed the party already (I'm a new moderator here), and while it sounds like some of our other members already gave you some great food and decor suggestions, I was also thinking that you could do a "Build Your Own" sandwich station for the adults or even a "Build Your Own" ice cream sundae station for the kids -- just to keep in line with the construction theme. For more ideas, check out some of Betty Crocker's party-planning tips and decoration ideas at http://www.bettycrocker.com/entertaining/birthday-parties/

Mere