Short answer. You are not responsible for normal wear from ordinary use. Article 1943 of the Civil Code says the bailee does not answer for deterioration of the loaned thing that is due only to use and without the bailee's fault. If the equipment simply aged from normal operation, that is the bailor's risk, not yours.
What the law says
The bailee does not answer for the deterioration of the thing loaned due only to the use thereof and without his fault.
Civil Code, Article 1943 — Deterioration From Use. Read the full provision →
The basic rule on wear and tear
In a commodatum — the type of loan where you borrow a specific thing and return the same thing — the bailor accepts that using the item will cause some deterioration over time. Article 1943 reflects this: "The bailee does not answer for the deterioration of the thing loaned due only to the use thereof and without his fault." The law draws a clear line: ordinary wear from use is not the bailee's liability. Only deterioration caused by the bailee's fault — negligence, misuse, exceeding the agreed purpose — creates an obligation to pay.
What the lender is claiming versus what the law requires
If the lender is demanding payment for gradual wear — faded paint on a vehicle, softened upholstery on furniture, reduced sharpness on a tool blade after extended cutting — Article 1943 protects you. These are the natural consequences of use that the bailor agreed to accept when they lent the item. The bailee is not an insurer of the thing's condition at the time of return. The lender can only succeed in a claim for deterioration if they can show that the damage goes beyond normal use and resulted from something the bailee did wrong or failed to do.
When the bailee is liable for deterioration
Article 1943 protects the bailee only when two conditions are met: the deterioration resulted only from use, and the bailee was without fault. If the bailee used the thing in a way that was not authorised — for a different purpose, in a different location, or for a longer period than agreed — and that use caused additional deterioration, the bailee may be liable for the excess damage. Similarly, if the bailee was negligent in caring for the thing — leaving equipment exposed to rain when it should have been stored, for example — fault is established and the protection of Article 1943 may not apply.
Documenting the condition at handover
Disputes about wear and tear are often difficult to resolve because neither party documented the item's condition when the loan began. If you are currently involved in such a dispute, evidence of what the equipment looked like before and after the loan period — photographs, a written condition report at the start, witness accounts — will matter. If you are about to borrow something valuable, consider preparing a simple written record of the item's pre-loan condition, signed by both parties. This protects both the bailee against exaggerated claims and the bailor against a bailee who genuinely causes damage and then claims it was normal wear.