Wentworth Limestone Supply Project – Update
An update on the Wentworth Limestone Supply Project
The Wentworth Estate is one of the UK’s most exclusive private neighbourhoods. It is home to some of the most expensive high end builds in the country.
The Estate was established in the 1920’s by W. G. Tarrent, the same builder who developed St George’s Hill in Weybridge. Work stopped during the depression and both world wars therefore the majority of plots were not completed until the 1960’s. Recently most schemes on this estate tend to be a complete knock down and rebuild. Typically in a Neo Georgian aesthetic with grand frontages consisting of brick and stone. Which is becoming more common in renewed developments on existing plots.
This scheme, which is backed on to the famous PGA golf course, has been designed with brick and natural stone. The stone features include large window surrounds, solid L shape quoins at the returns, front and rear classical porticos, extra large two story pilasters, ashlar to the front elevation, large entablature and pediment with cornice and copings. There is also a radius section with radius window surrounds and radius entablature, all finished off with an imposing entrance gateway.
Where did API Stone come in?
The journey for us started Q3 2020 with stone selection and some value engineering to the larger units. The value engineering saw us split into layers to save on block waste. At tender stage we were competing against a selection of other natural stone masons in our high end field. This resulted in us winning the order based on a competitive tender. API secured the supply on the basis of the strongest technical bid with the most developed options on cost saving for the clients.
The Portuguese Moleanos is a super hardy limestone with great test data. This stone was selected as a better value alternative to both French and Portland Limestone types. These were the stones which were originally specified at the pre-tender stage. The Moleanos has a grey grain/vein look to it which shows up on cross section cuts, across the quoins, across the cills. This results in a distinctive and recognisable appearance.
As well as supplying the stone, we are completing all the technical stone drawings where ever finite masoned edge has to be given a dimension. These drawings include four full size profiles to the more complex aspects, and cutting sheets for block sizes to the quarry. All API drawings are issued for architects and structural engineers before going into manufacture.
Wentworth Limestone Progress Photos
Stone Type: Portuguese Moleanos Limestone
Architect: Ascot Design
MC: EAB Homes
Stone Subcontractor: Surrey Stone Solutions
Stone Supplier: API Stone
Conroy Brook Developments Award
2018 CONROY BROOK DEVELOPMENTS AWARD
Conroy Brook Developments is one of our longstanding and regular customers. We were delighted to see they have won the residential development of the year award at the Insider Property Awards 2018 for Pennine Gardens, Upperthong. We supplied them with API Beige walling and traditional detailing of heads, cills, mullions, dentils and copings. The whole development creates an image for what API Stone can produce for our clients.
As of November 2018, Conroy Brook Developments has been shortlisted for Builder of the Year Award, with other projects also featuring API Stone supply.
You can visit their site here.
RIBA Sterling Prize Winner
The 2018 RIBA Sterling prize was announced this week, the winner is the Bloomberg Building, by Foster + Partners. Priced at around £1B, it uses 9600 tonnes of the Derbyshire sandstone, Stanton Moor, from Marshalls. The same stone was used over the street on the Victorian court house. Love it or hate it, it is a worthy winner out of this years shortlisted projects. It is the most amount of natural stone used on a central London project in over a century.
Under Construction in 2016:
The project has been underway for ten years, and has the highest BREAAM rating for any corporate building in the world at 98.5.
You can hear project lead Michael Jones talk about the design process and the requirement for collaboration in the brief, as well as the old-and-new tension encountered in the natural building products, like the stone and the relocated Roman Temple compared to the more modern high sustainability in the building use.
This is a short video by Architects Journal featuring Micheal Jones of Foster + Partners:
Architect: Foster + Partners
Main contractor: Sir Robert McAlpine
Structural engineer: AKT II
Lighting engineer: Tillotson Design Associates
Building services engineer: Sweco
For other shortlisted projects for this years Sterling go to the RIBA website here.
Marshalls quarry the stone out of the ground making the block available. This is where organisations like us come in. API Stone can source Stanton Moor sandstone direct from Marshalls in the form of block by the tonne, and we can cut and dress the stone as required for a project, whether typical handset like the Bloomberg, modern rainscreen, or traditional detailing works. Give us a call and we can go through your project and see what stone type would suit you, cost from drawings and organise samples.
Feel free to fill in our contact form.
Two Main Natural Stone Cladding Types
Stone Cladding Types:
The two main types of anchoring back stone in the construction of large buildings is either: 1) traditional handset (also known as “ashlar”), where the stone pieces are held back by fixings and applied in courses, or: 2) rainscreen, where the stone is positioned on a metal railing system. The design choices for anchoring can be determined by the style and use of the building.
Handset / Ashlar
Traditional handfixing the stone is still the most common use in cladding, particularly in the North of England and Scotland. The stone is held back by restraint fixings with horizontal load bearing being situated every floor or every other as determined by a specialist structural engineer. The load bearing fixing can be anchored with a pistol back rebate to the bed of the stone cladding. It takes a specialist fixing team to apply dowel pins to each stone piece anchored to SFS or block substrate.
Dowel pins such as the one illustrated here serve to hold back an entire floor level before horizontal is needed. Pin holes are usually drilled on site by the fixing team. The joints between courses can either be left as expansion gaps or filled with a matching stone mortar grout.
In estimating cost for a project with handset consideration should be given to supply of the natural stone, cut, dressed and sent to site, and also anchoring pieces and the fixing fee of a specialist stone subcontractor.
A natural stone rainscreen system is a means of cladding by which stone panels are supported on a steel or aluminum frame. Such a frame consists of helping hand with vertical supports and horizontal ”T” bar the stone is pinned back by.
These systems have stronger pull-out load bearing capabilities such that the stone panels can be thinner than their handset equivalents; where handset tends to be 50-100mm thick, rainscreen stone panels tend to be 20-30mm thick.
The advantages of the rainscreen are in ease of application and simplicity of loadbearing; each course is independent – compared to handset that needs horizontal supports to each new floor level. The disadvantages of rainscreen is the necessity of procuring the rail, usually at an equivalent to the thinner stone cost, the saving tends to be on the application labour. Handset is still the only way to go for complicated designs with quions or radius features.