Concrete admixtures and mortars from China

6% duty

Read from the UK Trade Tariff on 27 September 2026, prepared additives for cements, mortars or concretes (3824 40 00 00), non-refractory mortars and concretes, whether ready to pour or dry-mixed (3824 50), and fireproofing, waterproofing and similar protective preparations used in the building industry (3824 99 70 00) all carried 6% on goods from China, with no anti-dumping measure.

Cement itself is classified under heading 2523, refractory mortars under 3816, and polymer sealants and mastics under 3214, so confirm the commodity code from the composition. Cement-based tile adhesives and renders are usually dry-mixed mortars. Structural adhesives are covered in our glues and adhesives guide.

Standards, marking and chromium VI

Under the Construction Products Regulation (EU) No 305/2011, as it applies in Great Britain, a construction product covered by a designated standard needs a declaration of performance and UKCA marking before it is placed on the market. Designated standards include BS EN 934-2 for concrete admixtures, BS EN 998-1 and BS EN 998-2 for rendering and masonry mortars, and BS EN 12004 for ceramic tile adhesives.

Under the UK REACH restrictions, cement and cement-containing mixtures must not contain more than 2 mg/kg of soluble chromium VI when hydrated, so cement-based mortars need a reducing agent and a shelf life on the bag. Cement mixtures are hazardous, so bags need hazard labelling and a safety data sheet.

Specifying construction chemicals

Specify the product type and performance class (water reduction for admixtures, compressive strength class for mortars, adhesion class such as C1 or C2 for tile adhesives), solids content and dosage for liquids, setting time, open time, bag weight and shelf life, and the declaration of performance and test reports.

Worked duty example

For a made-up shipment of 20 tonnes of polycarboxylate superplasticiser under 3824 40 00 00, add the £2,400 of freight and insurance to the £26,000 free-on-board price and customs sees £28,400. At 6%, duty on these superplasticiser is £1,704; import VAT of £6,020.80 is 20% of the value with duty added. Together that is £7,724.80, but a VAT-registered importer usually gets the VAT back. The duty and VAT guide walks through the calculation.

Inspection checklist

Performance: have an independent laboratory test a sample from the lot for the declared properties, such as water reduction and setting time for admixtures, or strength and adhesion for mortars.

Documents: check the declaration of performance, the UKCA marking and the test reports match the product and lot, and that bags show the chromium VI shelf life and hazard labels.

Packing: check bags are moisture-proof, pallets are wrapped, liquid admixtures are in sealed drums or IBCs, and the manufacture date leaves enough shelf life after the voyage.

What goes wrong

Construction chemicals fail on performance, shelf life and paperwork. A superplasticiser has lower solids than stated, a mortar sets too fast or cures weak, damp gets into bags on the voyage, the chromium VI reducer expires before use, and products arrive without a declaration of performance.

Test each lot, allow for shelf life in the shipping plan, and check documents before loading. See our quality inspection guide.

Cambridge China Bridge sources admixtures, mortars and waterproofing compounds for UK builders' merchants and contractors, checking the plant's laboratory and test records first. See factory verification.