[madmmac]

Did he do a good job?

If so, give him $500 for doing the first half and $500 when he finishes the second half.

Tell him that you are very happy with his work and say that in this day and age that nobody does any work without some money up front and that it was nice that he trusted you so much. Remind him that he was supposed to have called and that you would have requested a little heavier application of sealer if given the chance.

Again, compliment him on his good work and ask when they will complete the rest of the job. Write him the $500 check and say he will get the rest when completed.

If they did a crappy job.....it may go south from there.