900m2+
Flooring installed: Stone Seal Trowel
10mm
Predominant thickness old & new floor build ups
5
Buildings – 19 spaces
3
Controlled colours, grey, light grey & black
Project & Design Intent
Beer was first brewed at Old Brewer’s Yard in 1722. Its £73 million redevelopment into Guinness Open Gate Brewery London adapts eight Grade II listed buildings into a 54,000 sq ft working microbrewery and visitor destination. Three centuries of character could stay: exposed brick, large window openings, the marks of a working site. The floors could not.
The design intent called for coloured polished concrete beneath that brick and daylight: quiet rather than decorative, with trowel movement and tonal variation but no exposed aggregate. Two colours, light grey and dark grey, and a third, black, for one circular floor: Step into The Pint, a flagship interactive feature. One plane through five of the buildings, past curves, thresholds, brass and retained fabric.
Anyone who has worked in a listed building will recognise what came next.
The Technical Challenge
Polished concrete takes its finish from the slab beneath it. At Old Brewer’s Yard there was no slab to take it from. The existing screeds had delaminated in places and were holed and voided in others, beyond recovery as a surface. There was no depth for a new slab, and above ground the retained construction could not carry one.
Nor was there a single floor to solve. Retained screed, remediated screed, new screed, concrete board and levelling over old flagstones lay beneath different spaces. Some areas offered a 10 mm floor zone; others needed 25 mm built to reach datum. At the south entrance to Mercer Walk the threshold sat about 47 mm below the proposed screed.
The requirement was therefore to achieve the continuous character of coloured polished concrete within retained floors that could not accept a concrete slab.
Challenges & Solutions
CHALLENGE
Existing screeds across the site were damaged and delaminated, holed and voided in places, leaving no sound, continuous surface that could simply be finished as it stood.
SOLUTION
Every floor was surveyed first, checking for hollowness, voids, cracks and moisture. Loose material was stripped out, failed areas rebuilt, and sound retained screed kept and prepared rather than replaced.
CHALLENGE
There was no depth in the existing floor zone to pour a new concrete slab, and the retained structure above ground was simply too fragile to carry the weight of one at all.
SOLUTION
Stone Seal Trowel separates concrete character from concrete construction. A 10 mm overlay delivered a polished concrete finish without a slab’s weight sitting on structure never built to carry one.
CHALLENGE
Matching one coloured concrete character consistently across five separate buildings and multiple installation phases risked visible tonal variation between areas finished weeks or months apart.
SOLUTION
Where polished concrete reveals its colour only once ground, here colour is specified against an approved sample panel, with natural tonal movement within it and little or no aggregate exposure.
CHALLENGE
Applying flooring across 900 m² and five separate buildings, each on a different phase, substrate and construction timeline, risked the finish reading as disconnected jobs rather than one continuous surface.
SOLUTION
Applied as one wet-laid, hand-trowelled system rather than pre-formed sections allows the floor to run continuously across building lines and substrate changes — 900 m² read as one unbroken surface.
Technical Delivery
Stone Seal reviewed every receiving floor for delamination, voids, cracks, moisture, depth and thresholds before proposing a build-up. Loose material came out; failed areas were rebuilt; sound screeds were kept. At Mercer Walk a slip membrane and fibre-reinforced screed went beneath the topping; elsewhere a 15 mm uplift made a 25 mm zone under the 10 mm finish.
At the south entrance the 47 mm discrepancy was absorbed in the screed, not the finish, so topping, mat well and door meet at one level. Curves and colour lines were set out before application; brass profiles were primed and sand-broadcast so the topping bonded to them. Stone Seal delivered the designated screed and the finish, and coordinated board areas, joints and thresholds with Bennett Construction (London) Limited.
Fix the finish first; work every layer backwards from it.
The specified floor
Compressive Strength C80
Flexural Strength F20
A1fl
EMICODE EC1 PLUS
Böhme A5 to A1,5
- Tested & certified
- Trowelled Finish
- Ultra-high performance
- Fast application
- Seamless joint-free flooring
- No cracks or micro spalling
- No shrinkage or contraction
- Customisable colour range
- ASTM & CE mark
- Exceptional abrasion resistance
- Aesthetic – natural look
- Slip resistant – certification supplied
- Matt, mid-sheen & high gloss finish
- Complete architectural freedom
Take A Look Inside!
The Result
The completed floor reads as one plane of coloured concrete character across five buildings. Stone Seal Trowel was installed at predominantly 10 mm, with structural joints carried through and no contraction-joint grid.
The London Brewery opened its doors in December 2025.
