Help with classification of item with multiple materials

Good morning,

Would anyone be able to assist with the classification of a ‘wet room tray’. It consists of a stainless steel drain, plastic (PP) outlet and a board / tray which is manufactured from 1 layer, polymer mortar, 1 layer extruded hard foam (extruded polystyrene), 1 layer polymer mortar and 1 layer alkali mesh

The manufacturer has provided code 3918909000 which is for plastic floor coverings. I assume this is because the majority of it is polystyrene, however I want to double check this as my understanding is that each material used within the product needs to be broken out and import duty is applied for each elemental which makes up the product.

If it correct that all materials need to be categories, how do you do this? Would it be e.g. the product price + shipping etc = £100 and it weighs 10kg, the stainless steel in the product weighs 2kg, so that’s £20 of the product. So the stainless steel import duty is applied to the £20 + VAT? and then the remaining 80% will have the relevant duty applied.

Any assistance would be greatly appreciated.

Regard, Sean

Take a look at Section 39 22