If an item or interest is insured with more than one insurer for amounts that in total exceed the value of the insured item or interest, each insurer shall be obligated to pay a share proportionate to the ratio between the value of the insured item or interest and the total sum insured, without the total amount paid to the insured exceeding the value of the damage they sustained from the fire.
Interpretation and application must be checked against the official text and current version.