Sourcing sealants and caulks from China

4% duty

Read from the UK Trade Tariff on 27 September 2026, heading 3214 covers glaziers' putty, grafting putty, resin cements, caulking compounds and other mastics, painters' fillings, and non-refractory surfacing preparations for façades, walls, floors and ceilings. All 3 lines carried 4% on goods from China, with no anti-dumping measure.

One listed product has a 0% suspension to 31 December 2028 within 3214 10 10 00: an adhesive, sealant or coating material with a tensile strength of more than 434 PSI, for sealing and protecting electronic components in aviation, defence and electronics applications, not of Russian or Belarusian origin. Ordinary construction sealants stay at 4%.

Adhesives and glues are heading 3506 (see our glues guide), and silicones in primary forms that are not ready-to-use sealants are 3910, so confirm the commodity code from the product as sold.

Construction marking and chemical labels

Sealants for façade elements, glazing, sanitary joints, pedestrian walkways and cold-climate use are covered by the harmonised standard series BS EN 15651 under the retained Construction Products Regulation (EU) No 305/2011, so they need a declaration of performance and UKCA or CE marking with the class for each use. Sealants not placed on the market for those construction uses fall outside that system but still need to be safe and correctly labelled.

Sealants that meet a hazard classification, such as those containing isocyanates or certain solvents, need labels and a safety data sheet under the retained CLP Regulation (EC) No 1272/2008. Sanitary sealants with an anti-mould claim are treated articles under the retained Biocidal Products Regulation (EU) No 528/2012, so the fungicide must be approved for that use and the label must name it.

Specifying sealants

Specify the chemistry (acetoxy or neutral-cure silicone, acrylic, polyurethane, MS or hybrid polymer), the BS EN 15651 part and class, movement capability, Shore A hardness, skin time and cure rate, colour, primer requirements, cartridge or sausage size, nozzle, shelf life and storage temperature, and the label languages.

Worked duty example

Take a hypothetical order of 20,000 cartridges of 300 ml sanitary silicone sealant, entered under 3214 10 10 00: £16,000 free on board plus £1,800 of freight and insurance gives a customs value of £17,800. The 4% duty on sealant cartridges comes to £712, and import VAT is 20% of £18,512, which is £3,702.40. If you are VAT-registered you normally reclaim the £3,702.40, leaving £712 as the real cost at the border. Step by step: UK import duty and VAT.

Inspection checklist

Documents: check the declaration of performance and test reports cover the BS EN 15651 part and class claimed on the label, and check the safety data sheet and CLP label.

Performance: test tensile properties at maintained extension to ISO 8339, elastic recovery to ISO 7389 and slump to ISO 7390 on production samples, and run mould resistance to ISO 846 for sanitary grades.

Cure and packing: record skin time and depth of cure on a sample bead, check colour against the standard, weigh fill per cartridge, and check nozzles, plungers and batch and expiry dates.

What goes wrong

Sealant orders fail on formulation, shelf life and claims. A cheaper filler-heavy mix shrinks and cracks, acetoxy silicone attacks metal or stone, cartridges cure in the tube before the expiry date, anti-mould grades go black in months, and the label claims a class the test report does not cover.

Test cured samples from each batch and check expiry dates on arrival. See our quality inspection guide.

Cambridge China Bridge sources sealants and fillers for UK builders' merchants and own-label brands, checking the formulator's test reports first. See factory verification.