# Larsen Trade Semi-Fast Set Flex (Trade Grey Bag)

Tile adhesive · Larsen

Larsen Trade Semi-Fast Set Flex (Trade Grey Bag) takes about 4 kg a square metre, by Larsen Building Products' own figure: “Coverage: Approx. 4kg/m2 @ 3mm bed”.
Source: Larsen Building Products, Larsen Trade Semi-Fast Set Flex (Trade Grey Bag) product page, read 12 October 2026.

What it is for, in the maker's words: “Larsen Trade Semi-Fast Set Flex is a fully flexible, S1-rated, microfibre reinforced, non-slip, cement-based adhesive” (Larsen Trade Semi-Fast Set Flex (Trade Grey Bag) technical data sheet, read 12 October 2026).

## The maker's figures

| Figure | The maker's words |
|---|---|
| about 4 kg a square metre | “Coverage: Approx. 4kg/m2 @ 3mm bed” |
- The conditions the maker names: Each figure is for the notch, bed, tile or joint the maker names beside it. An uneven surface, a larger notch or buttering the backs of the tiles takes more.
- Waste: None of these figures adds anything for what is left in the bucket or spilt.

## What one bag covers at the maker's rate

| Rate | A 20 kg bag |
|---|---|
| about 4 kg/m² (“Coverage: Approx. 4kg/m2 @ 3mm bed”) | about 5 m² |

Arithmetic on the maker's figure: the bag's kilograms divided by a rate a square metre, or times an area a kilogram, with nothing added for waste.

## Sizes

20 kg bag

## Where to buy it

The page has the shops' own searches for it, and any link there that is paid for is marked Ad: https://buildbatch.co.uk/products/larsen-trade-semi-fast-set-flex-trade-grey-bag/#where-to-buy. BuildBatch sells nothing and compares no prices.

## Questions

**How much does a 20 kg bag of Larsen Trade Semi-Fast Set Flex (Trade Grey Bag) cover?** Larsen Building Products gives a rate a square metre, not an area a bag. At its rates a 20 kg bag covers about 5 m² (“Coverage: Approx. 4kg/m2 @ 3mm bed”): the bag's kilograms divided by the rate, with nothing added for waste.

**How much Larsen Trade Semi-Fast Set Flex (Trade Grey Bag) per square metre?** Larsen Building Products states about 4 kg a square metre (“Coverage: Approx. 4kg/m2 @ 3mm bed”).

**What is Larsen Trade Semi-Fast Set Flex (Trade Grey Bag) for?** Larsen Building Products says: “Larsen Trade Semi-Fast Set Flex is a fully flexible, S1-rated, microfibre reinforced, non-slip, cement-based adhesive” (Larsen Trade Semi-Fast Set Flex (Trade Grey Bag) technical data sheet, read 12 October 2026).

**What sizes does Larsen Trade Semi-Fast Set Flex (Trade Grey Bag) come in?** The catalogue lists 20 kg bag. A shop may not stock every size.

## Where the figures come from

- Larsen Building Products, Larsen Trade Semi-Fast Set Flex (Trade Grey Bag) product page (https://larsenbuildingproducts.com/product/semi-fast-set-flex-trade-range/): coverage, read 12 October 2026.
- Larsen Building Products, Larsen Trade Semi-Fast Set Flex (Trade Grey Bag) technical data sheet (https://larsenbuildingproducts.com/?jet_download=122b569fc00ce65f75047bcab8a8f2c8f8438ee6): what it is for, read 12 October 2026.

Written with AI tools; not yet checked by a tradesperson. Follow the bag's own instructions.

The page: https://buildbatch.co.uk/products/larsen-trade-semi-fast-set-flex-trade-grey-bag/