This isn't about how clean your home is
Checking secondhand furniture is just practical routine. It isn't a reason to avoid secondhand pieces altogether.
Where to look
Seams, folds, and the underside of cushions on any upholstered piece are the easiest places to spot early signs. On a mattress or box spring, check along the piping and seams. On a wooden piece, drawer joints and the underside of the frame are worth a look.
Before it comes inside
A quick check in the garage, driveway, or wherever it's first unloaded, before it goes into a living space, is the most useful habit. If anything looks off, it's worth a professional look before the piece comes further into the home.
Common questions
Should I avoid secondhand furniture altogether?
Not necessarily, a quick check before bringing a piece inside is generally enough as routine precaution.
I already brought a piece inside, should I check it now?
Yes, checking now is still worthwhile, and an inspection can help if you're unsure what you're looking at.
Are mattresses riskier than other furniture?
Not inherently, but the seams on a mattress are a common hiding spot, so they're worth a careful look.