41 CFR 302-7.10: -7.10 Weight additive costs.

(a) Employees will not be responsible for the shipping charges that result from a weight additive so long as the actual weight of the HHG without the additive does not exceed the 18,000 pound net weight allowance for relocation. However, employees are responsible for any amount of their HHG that exceeds the 18,000 pound net weight allowance prior to the addition of the weight additive (e.g., when a weight additive of 700 pounds is imposed by a HHG carrier for a 65-pound canoe and the total net weight of the HHG, including the weight additive, is 18,765 pounds, the employee is only responsible for the 65 pounds actually added by the canoe).

(b) Employees are also responsible for the cost of special packing, crating, and handling of the weight additive items, if any. See § 302-7.200 on how charges are paid and who makes the shipping arrangements.