Brickwork that is not merely decorative should be done by professionals only. But as any professional bricklayer will tell you, the job can be overloaded with dangers. If you are working on a fairly straightforward decorative brickwork around a fireplace or as a base for an outdoor barbecue, you may encounter few problems- a crooked layer here or a slight tilt there. But any brickwork that involves a load-bearing wall or unusual angles or height should be left to professional bricklayers and masons. Small deviations from plumb may be okay for a backyard grill, but could cause an entire wall to collapse if unchecked.
Professionals have the proper tools and techniques to prevent collapse due to improper alignment.
If the job involves load-bearing structures, installation procedures must be followed to the letter, which usually means leaving the project in the hands of experienced workers. Replacing a leaky toilet, for example, is an involved process but not overly complicated. Pipes for drains and sinks are standard sizes, and will come off with traditional wrenches without much effort. Many drainage problems can be solved with 'over the counter' products such as chemical clog removers and pipe cleaners. Flooding and excessive water damage can be two of many problems associated with improper plumbing repairs.