Most of us have at least one property locked in at a rate we'll never see again. The frustrating part is that those are usually the properties with the most equity, and refinancing means giving that rate up.

A second lien solves it, and I don't see it discussed here much.

How it works. A second mortgage sits behind your existing first. The first stays exactly as it is. You only pay interest on the new money.

Two flavors. A closed-end second is a fixed-rate lump sum at closing. A HELOC is a revolving line you draw from over time.

Why it matters for investors specifically. If you've got a rental at 3.5 percent with substantial equity, a cash-out refi costs you hundreds a month on the balance you already had before you see a dollar of new money. A second lien charges you only on what you actually pull.

What to watch:

CLTV on a HELOC is usually calculated on the full credit line, not the drawn balance. A $200,000 line counts as $200,000 against your equity even if you only draw $50,000. That's the single most misunderstood thing about these products.

Seasoning matters. Most programs require the first lien to be at least six months old, fixed rather than adjustable, and reporting on credit.

Some programs require a minimum draw at closing. I've seen 80 percent required on some HELOCs, which defeats the purpose if you wanted a standby line.

Prepayment penalties exist on some second liens and not others, and they range from one to five years. Worth asking before you sign.

On investment properties, terms are tighter than on a primary. Expect lower CLTV limits and higher rates. Some programs will qualify the second on the property's rent using DSCR rather than your personal income.

Happy to answer specifics.