A home-equity loan, also known as a second mortgage, lets homeowners borrow money by leveraging the equity in their homes. Home-equity loans exploded in popularity in 1996 as they provided a way for consumers to somewhat circumvent that year's tax changes, which eliminated deductions for the interest on most consumer purchases. With a home-equity loan, homeowners can borrow up to $100,000 and still deduct all of the interest when they file their tax returns. Here we go over how these loans work and how they may pose both benefits and pitfalls.

Home equity loans come in two varieties - fixed-rate loans and lines of credit - and both types are available with terms that generally range from five to 15 years. Another similarity is that both types of loans must be repaid in full if the home on which they are borrowed is sold.

A home-equity line of credit (HELOC) is a variable-rate loan that works much like a credit card and, in fact, sometimes comes with one. Borrowers are pre-approved for a certain spending limit and can withdraw money when they need it via a credit card or special checks. Monthly payments vary based on the amount of money borrowed and the current interest rate. Like fixed-rate loans, the HELOC has a set term. When the end of the term is reached, the outstanding loan amount must be repaid in full.

Home-equity loans provide an easy source of cash. The interest rate on a home-equity loan - although higher than that of a first mortgage - is much lower than on credit cards and other consumer loans. As such, the number-one reason consumers borrow against the value of their homes via a fixed-rate home equity loan is to pay off credit card balances (according to bankrate.com). Interest paid on a home-equity loan is also tax deductible, as we noted earlier. So, by consolidating debt with the home-equity loan, consumers get a single payment, a lower interest rate and tax benefits.

Home-equity loans are a dream come true for a lender, who, after earning interest and fees on the borrower's initial mortgage, earns even more interest and fees. If the borrower defaults, the lender gets to keep all the money earned on the initial mortgage and all the money earned on the home-equity loan; plus the lender gets to repossess the property, sell it again and restart the cycle with the next borrower. From a business-model perspective, it's tough to think of a more attractive arrangement.

Home-equity loans can be valuable tools for responsible borrowers. If you have a steady, reliable source of income and know that you will be able to repay the loan, its low interest rate and tax deductibility of paid interest makes it a sensible alternative. Fixed-rate home-equity loans can help cover the cost of a single, large purchase, such a new roof on your home or an unexpected medical bill. And the HELOC provides a convenient way to cover short-term, recurring costs, such as the quarterly tuition for a four-year degree at a college.

The main pitfall associated with home-equity loans is that they sometimes seem to be an easy solution for a borrower who may have fallen into a perpetual cycle of spending, borrowing, spending and sinking deeper into debt. Unfortunately, this scenario is so common the lenders have a term for it: reloading, which is basically the habit of taking a loan in order to pay off existing debt and free up additional credit, which the borrower then uses to make additional purchases.

Reloading leads to a spiraling cycle of debt that often convinces borrowers to turn to home-equity loans offering an amount worth 125% of the equity in the borrower's house. This type of loan often comes with higher fees because, as the borrower has taken out more money than the house is worth, the loan is not secured by collateral. Furthermore, the interest paid on the portion of the loan that is above the value of the home is not tax deductible.

If you are contemplating a loan that is worth more than your home, it might be time for a reality check. Were you unable to live within your means when you owed only 100% of the value of your home? If so, it will likely be unrealistic to expect that you'll be better off when you increase your debt by 25%, plus interest and fees. This could become a slippery slope to bankruptcy.

Another pitfall may arise when homeowners take out a home-equity loan to finance home improvements. While remodeling the kitchen or bathroom generally adds value to a house, improvements such as a swimming pool may be worth more in the eyes of the homeowner than the market determining the resale value. If you're going into debt to make cosmetic changes to your house, try to determine whether the changes add enough value to cover their costs.

Paying for a child's college education is another popular reason for taking out home-equity loans. If, however, the borrowers are nearing retirement, they do need to determine how the loan may affect their ability to accomplish their goals. It may be wise for near-retirement borrowers to seek out other options with their children.

Food, clothing and shelter are life's basic necessities, but only shelter can be leveraged for cash. Despite the risk involved, it is easy to be tempted into using home equity to splurge on expensive luxuries. To avoid the pitfalls of reloading, conduct a careful review of your financial situation before you borrow against your home. Make sure that you understand the terms of the loan and have the means to make the payments without compromising other bills and comfortably repay the debt on or before its due date.