Dear James: We have drain clogging issues in our relatively new house. I wonder if it was not plumbed properly.

Are there any drain cleaner chemicals that really work?

— Michelle T.

Dear Michelle: It would take a thorough inspection to determine the cause of drain clogs. The normal aging process, the plumbing may have too many bends or it may be an inadequate size can all cause problems. Without tearing the walls open, the former two are difficult to determine.

There is natural buildup of some gooey stuff called bio-film. It slowly builds up over time from bacteria acting on food particles, soaps, conditioners, body oils, toothpaste, etc.

This black gunk is very sticky and gradually hardens like creosote in a chimney. Ten years is a typical time when the buildup often begins to cause problems.

Bathtubs are usually one of the worst drains for this. Long hairs tend to get stuck in the bio-film and form a tough solid blockage.

Also, bathtub drains often have a fairly long, nearly horizontal drain run under the tub. The water velocity is slow through this area, creating a faster buildup.

When you have a clog, you can try to use a standard old plunger, but it will probably just pump out a lot of the smelly black gunk.

A drain-cleaning snake usually works, but it gets messy, too. If your plumber put in too many sharp elbows, the snake may not reach the point of the clog.

Unless you have a septic tank system, a standard liquid drain cleaner is your most effective and less expensive option. The ones called “thick” are supposed to settle through the standing water and make their way to the clog.

Do not use these with a septic system because the harsh chemical drain cleaners can kill the good bacteria in the septic tank. Without the bacteria, the septic tank is ineffective.

Use enzyme cleaner regularly to keep the drains clean. A clog will often require a call to the plumber.

If you have a wet/dry vacuum, use it to remove as much of the water from the pipe as possible. This reduces the dilution of the drain cleaner.

First ladle the standing water out of the sink or tub. Seal off any overflow openings and let the vacuum suck out the water.

Pour the thick cleaner in the drain and let it stand as long as the packaging indicates.

Instead of just turning on the water and the recommended time period, put a stopper or rag over the drain and fill it half full. Remove the stopper and the water flow will have more force.

Drano makes a foaming type of drain cleaner. This is particularly effective for cleaning the entire inside surface of the drain pipe because it foams and expands.

Standard cleaners, even the thick ones, only come in contact with the bottom surface of the pipes due to gravity.

If you have a stubborn clog, both Drano and Liquid-Plumr have voice and online help lines that you can contact. If you end up needing professional help, make sure to tell the plumber that you used drain cleaners so he does not get chemical burns.

For those of you building a new home, plan the plumbing carefully. Use as few 90-degree elbows as possible. For horizontal drain pipes, a slope of ⅜-inch per foot length is ideal to keep the water flowing fast.

Consider using 2-inch drain pipe for bathtubs instead of standard 1½-inch pipe. This makes is much easier to feed a snake through when there is a clog.