In looking for a full tanking solution for the ensuite bathrooms of Michelin Star and celebrity chef Michael Caines’ dream project, natural stone specialists Devon Stone elected to use a complete Schlüter®-KERDI-BOARD and tanking solution.

Project Overview

The project took a Grade II listed Georgian manor house and converted it into a striking contemporary country house hotel with 21 guestrooms. As well as Michelin Star cuisine and Relais & Chateau luxurious and elegat interiors, Lympstone Manor has pride of place overlooking the Exe estuary, a Site of Special Scientific Interest (SSSI) due to the wildlife it supports.


AREA: Bathrooms (Floors and Walls)

ACTION: Providing a smooth and waterproof substrate for marble finishes

The Challenge

Lympstone Manor had been in a gradual state of deterioration since the early 20th century. It was purchased by Michael Caines in 2014, with the intention that it would become his flagship establishment. Devon Stone were introduced to the project to specify the natural stone element of the twenty one bathrooms as well as the fine dining space. These designs had been signed off by Michael Caines, but the structure as it stood was unable to support them coupled with extreme water sensitivity due to the amount of lime present in the property.

Designing Lympstone Manor, Rud Sawer Architects were looking to achieve a waterproof assembly for floors and walls that came in at the right budget, but that also avoided compromising the premium quality that had already been benchmarked. In addition, the solution needed to factor for the ability of a listed and less than ideal structure to support the weight of the proposed marble and travertine coverings. The final requirement was to address the irregular surfaces of walls and variations in floor level throughout the project.

The Solution

Rud Sawer Architects were originally looking at using plywood over studs to bring everything level and square and allow for mechanical fixing of the coverings, but were conscious that this alone wasn’t a suitable substrate for tile and stone installation in wet areas.

This led to the specification of two thicknesses of the multi-functional backerboard, Schlüter®-KERDI-BOARD and associated sealing products KERDI-KEBA and KERDI-COLL-L.

Given the nature of the project, if water does manage to cause an issue, it will not only cost a considerable amount to put right but risk disappointment to discerning clients. The project therefore needed a zero failure total solution. Devon Stone worked with their specification partners Schlüter and CodeX (an Uzin company) due to their unrivalled product knowledge and expertise in the UK to produce a total solution from substrate to installed natural stone.

Product Usage

The proposed plywood was eliminated completely from the wall assembly, being replaced by Schlüter® KERDI-BOARD in a thickness of 12.5mm. Floors within the project were constructed of 18mm plywood, lined with a mix of 5mm and 12.5mm KERDI-BOARD, depending upon floor heights. All boards were then sealed with KERDI-KEBA and KERDI-COLL-L to form a fully waterproof base for the first quality and certified natural stone tiles by Devon Stone, which included Crema Marfil, Estromoz and Nero Marquina marble, as well as Peruvian travertine, all in 600 x 600 x 20mm sizings.

Devon Stone also made use of Schlüter’s specialist KERDI-BOARD variant, Schlüter®-KERDI-BOARD-V, to waterproof the curved shower walls as a feature in some of the bathrooms. This product features pre-cut grooves that allow for the quick creation of a smooth curved surface that is ready for tiles or stone to be installed upon.

Cost and Weight Savings Achieved

By eliminating plywood from the wall assembly, costs were reduced by a significant percentage; use of KERDI-BOARD vs the original plywood solution proposed saved 11.7kg of weight per sq.m and produced a cost saving in excess of £16.00 per sq.m (totalling over £8000 across a total area of more than 500sq.m). It also offered a reduced installation time and negated the need for a separate tanking layer. Although we review each installation in it’s own technical context, the approach taken at Lympstone Manor has become a standard specification across Devon Stone’s bathroom and wetroom projects.

In the case of Lympstone Manor, KERDI-BOARD aided the creation of bathrooms that will support and protect an exquisite and highly personal accomplishment. The complete specification was runner up and highly commended at the prestigious Architects Journal Specification Awards 2019.