You could try looking up plumbing websites.
And if it helps ... something about marketing ...
Years ago I went on a self employed business course and put simply (very simply) marketing was about your typical customer. On the business course they made us think of our typical customer. Age, background, education, job, etc. How did that customer find me? Blah, blah ... Then you gear your advertising to gaining more of those customers. Eg, if your average customer is 50-70 years old, it's useless advertising in the local night club!