Probably going to get no end of grief for this, but here goes!
When a prospective client contacts you to quote for some work, they contact you because they want the job done professionally. The prospect, rightly, or wrongly assumes that you do indeed have the knowledge and expertise to carry out the work.
Upon visiting the client’s premises, you carry out your survey based on the needs of the client; sometimes the client has no real idea of how to maintain the surface, that’s exactly why they contacted you.
When this particular client told you that she wanted it cleaned and re-sanded, you as the professional should have pointed out the fact that this particular surface may need to be sealed, and of course advise the client of the potential problems that may arise if this sealing is not carried out.
As well as the problems inclement weather may cause after you have carried out the work.
All of this information and your recommendations should have been contained in your written quotation, signed and dated by yourself and you prospective client, one copy for you, the other for you customer.
This way, you have covered all the angles.
This particular client, may be trying it on, as he has stated that the area was sealed last time, however, in my opinion, by not following the advice given above, you have left wide open to this sort of complaint. Then again the client may have assumed that you know what you are doing, and is genuine in his belief that he paid you to do a job, and he doesn’t see why he should be held responsible for what he perceives to be your shortcomings on this particular job.
There is no real point in worrying yourself over this, just try to learn from it and be better prepared next time, get your paperwork in order, follow correct procedures, and hopefully all will be well.
Regards,
Rob