Fix Now, Save (A Lot) Later

Potential problem: Failing to maintain the boards' protective top coat of polyurethane can lead to ground-in dirt and discoloration, and cause wood to dry out and splinter.

Fix it now: At the first sign of wear, sand only the floor's surface and apply a fresh coat of polyurethane. Pros charge about $1.25 per square foot for this "screen and poly" job, or you can rent a floor-polishing machine and do it yourself for less. Just bring the machine back on time or the cost of additional days' rental could whittle away at your savings.

What you'll save: Up to $5 per square foot for a full-fledged refinishing, which requires sanding down to the bare wood. The overall cost depends on how old the floors are, the number of top coats needed, and if you are using stain. Replacing sections where dried-out wood has splintered or cracked starts at $125 and can go up substantially based on the scope of the damage and the floor type.

DIY: Learn how to screen a floor.