Skin of block has great depth and texture

Towards the end of last year we were approached by Keith Horn Architecture and Tom Hoblyn the well respected garden designer to source the travertine required for their garden, sponsored by Arthritis Research UK, at the Chelsea Flower Show. The garden design was inspired by the gardens at Villa Lante and Villa d’Este near Tivoli (http://thomashoblyn.com/chelsea). The Classic Roman Travertine was naturally to be sourced from the quarries in Tivoli. The contractor to undertake the difficult task of actually turning the concept into reality was Dan Riddleston, Bowles & Wyer Contracts Limited (http://www.bowleswyer.co.uk/). Dan had not only to coordinate the various aspects of the project – for example the complicated and high quality steelwork for the water feature, planting the 9m rocket trees imported from Tuscany and handling the massive pieces of stone – but had to get it done in just over a week!! Incredible.

The first and most important task was to work out the best way to create the rough quarry face required for the back wall. The rough hewn unharnessed aspect of the garden. I suggested the best way would be to actually use the skin from the travertine blocks extracted out of the quarry. This would obviously replicate the quarry face and as the quarry face is naturally split, not wire sawn or chainsaw cut it was as natural you could possibly get. In the garden this would be mixed with honed unfilled vein cut travertine and honed and filled travertine and the influence of man gathers pace from one end of the garden to the other.

Using block skins was a difficult option but once I had suggested this route the design team were keen to pursue it. We needed to make sure the skins were reasonably consistent in colour and finish, then the thickness had to be regulated to allow us to fix without too much trouble. These skins would be mixed with a smaller split face units made using a guillotine. this created the same finish as the huge pieces cut from skin. This method was limited in the sizes it can achieve so was not an option for the largest pieces if the scale of the original design was to be maintained.

The block skin idea caused a few more problems that we first envisaged. Not only the size, finish and thickness but the faces has dusty white naturally occurring deposits that in the main were able to be removed by a high pressure water jet (administered by me at times) then a localised acid treatment. Once all pieces washed and treated we dry laid everything for Tom and Keith to inspect prior to loading.

We also dry laid the smaller split pieces and also the 75mm thick seat formed from vein cut travertine honed and resin filled and with a full bullnose on two long edges. They were cut so the veins would match along the length. All the travertine selected for the garden was of exceptional quality and I look forward to seeing all the finishes together from rough hewn to unfilled, honed and cement filled, resin filled as well as sandblasted.

Construction is well under way and the guys have less than a week to finish. I will update you when it is all done.

Last week I took a trip to Verona with Canary Wharf Contractors and Commercial Stone Limited to view the production for six levels of Canary Wharf Tower taken by the Bank of New York. We were inspecting Verona Cream honed tiles and Virginia Mist polished vanity tops for the toilet pods. The Verona Cream limestone we we required needed to be clean with minimal fossil. This quality represents only around 10% of the production available from the quarry and to get to the selection means selection at every stage. We import the selected strips to Verona in 30mm thick and random lengths to then split, hone, calibrate and cut to the 305x305x10mm size specified.

We laid the 305mm tiles out on pallets in 16 tile lots. Each from a different crate to ensure we understood the quality of the whole consignment. We found was was very good material with some background variation but not too much and occasional fossils but they were generally grey not black shells that we have experienced in the past. Colour and fossil was consistent across everything we inspected. this was the first 285sqm and with another 5no floors to do we suggested that anything that was not in range should be noted and examples of these tiles sent back to keep at the end of the line so next time the operative responsible for selection can adjust accordingly.

The Virginia Mist vanity tops were very nice, material perfect, not too much white veining ad a deep blue/black in colour. All the vanity tops from all the floors will be made from one block we have reserved and set aside for the whole project. The bowl cut outs were being cut and polished during our visit using computer aided machinery. The tops had metal bars inserted as you can see from the pictures, giving strength across the three bowl cut outs.

The first floor is on site, the next being prepared and collected next month. The project will be delivered over the next six months as the floors are available.

Some impressive work was being done in the same factory, a plaque for the Vattican and some scuplting using a very special stone from Afganistan.

This week I received images of the CCP reception we completed at the end of 2011. It was a great project to be involved in this project where the Canadian client wanted to use a Canadian stone. The most striking and well known Eramosa was the obvious choice.

We required over 300sqm of floor stone and slabs for wall cladding, reception desk and a bench seat. The wall stones and bespoke slabs were polished and the floor was honed. The client requested a polished finish on the floor but for slip reasons we had to hone the tiles. They still look very similar to the polished ones because the stone is so hard. The tiles were 750x600mm with the grain running along the length. The wall tiles were cut from the same blocks as the floor to ensure consistency and the desk needed real precision to get the veins to match from one slab to the next. The architects were Originate and here have delivered a great space with the help of BW Interiors, Arena Stone & Ceramic and of course GDS.

I returned to Venice to inspect the finished production for Bank of China last week. The blocks had yielded some cracking material and once dry looked as per our approved mock up seen in November with TP Bennett & Overbury.

I intermingled the approved mock up tiles and the actual production and could not tell the difference between the tiles. A good sign indeed. The tiles were packed beautifully and loaded today on a trailer to London. We have even managed, in this particular case to record crate numbers from each block to allow the two help the stone contractor to fix  of the two areas using stone from the same areas in the quarry. The 1st floor (approximately 100sqm) will have just one block allocated to it. the ground floor (approximately 200sqm) will have one very large nice block (no. 500 – 12310kg) and an adjacent one in the quarry making what we hope to be an excellent job.

This week I visited a factory in Barcelona from which we buy Flint limestone. This order was for the project Coleman Street.

Required, 150sqm 700x700x20mm honed tiles. We were there to check the cutting tolerance, colour selection, packing and to seal a few tiles with the product we currently recommend CCC Swift Seal Ultra. This sealer is the best we know currently that can both seal incredible effectively whilst causing minimal or no colour change. Ramon, the quarry and factory owner sealed some tiles using our recommendation and also a couple using his own. He preferred the Anti Oil C from a Spanish manufacturer. This sealer he preferred was incredible, sealing and drying in seconds with no colour change at all. I am investigating this sealer to see if there are any distributors in the UK and examine the health and safety data available. I will report back if a contender but as of now we still recommend CCC Swift Seal Ultra for Flint Limestone. This sealer is excellent and supplied by Tom Wiseman’s company CCC based in Cumbria.

This sealer in combination with a ‘no water’ adhesive/fixing system will ensure the best results.

During our trip we were shown a new bed in the Flint quarry, this was similar to the Flint we know, a few more fossils but the best aspect was the fact that there is no big restriction in size. we can offer 800x800mm or 1000x1000mm tiles and extract the block according to the project. The Flint currently has a restriction of 600x600mm. The order inspected at 700x700x20mm was an exception. So Flint B2 (the new material) is more versatile in this respect. We will introduce this material on the site soon once tests carried out and data is available.

Recently we received an inquiry via our website requesting help to find a limestone being offered by the high street retailer Fired Earth to hopefully offer a saving.

We managed to locate the stone, actually the same as our Azul Castello but brushed instead of the standard honed finish. The tiles were selected from lighter slabs specifically ensuring the consignment was exactly the same as the Fired Earth offering. See the testimonial below written by the client, not by me!!!

“Our project was to create a wet-room using tactile natural stone. Pebbles were used for the shower floor with riven slate for the rest of the floor as well as for the skirting, window ledge, basin bases and splashback. We found some amazing blue grey limestone in a London showroom at an exorbitant price but sent a sample to Gareth Davies Stone. They responded immediately with the exact match (Azul Castello), obtained a new sample from Portugal as a check, and ordered the stone for us with the brushed finish we wanted at a third of the price. The effect complemented by the cupboards which were hand made in Cornwall and exceeded our expectations.” Dr Anthony Nathan

This week we visited a Pietra Serena Factory near Firenzuola, Italy. It is a busy factory with many contracts but one particular regular client requires exceptional selection and colour control to ensure all tiles are the same!!

The tiles are firstly dried and then all hand selected before being packed using quite an impressive machine.

This week we visited the Pietra Serena Quarry near Firenzuola, Italy. We luckily witnessed a block being blasted to move it away from quarry face, see video below. Also video of us entering the quarry to set the scene. Great quarry with very definitive strata and bedding plains.

Explosion moving a reasonabley sized block away from the face.

The quarry had clear layers along which the stone is extracted. Not only clear layers but the quarry is clearly not level, must have been at a 30 – 40 degree angle too! Using the drilling/pin method for the vertical the blocks are subesquently blasted using a low impact power to move them away from the face in order for the excavator to manoeuvre into a position to firstly have the clay scraped from the outer layers before being stacked ready for collection. This quarry was one of maybe 5 or 6 in operation, this being one of the biggest and most impressive. I think it one of the more interesting I have visited, actually quite exhilarating up there on top of the mountain. Amazing views including a quite reassuring sight of an older quarry no longer in operation, covered in trees and wildlife. This is an obligatory part of the deal, I think around 40,000 trees had been planted in this case and was barely noticeable languishing there in the hillside.

Entering the quarry in 4×4.

shellgrisabrasion44795g2.rep

This week I had to confirm the suitability of our Shell Gris for a very large commercial project I am currently working on. The building in The City would be the workplace for over 6000 people and with the design life of 50 years.  This requirement would mean the stone needs to withstand 150,000,000 visitors during its life (6000 x 2 (to and from work) x 250 (working days in the year x 50 (design life). If you add the fact that everyone might go out for lunch and that then doubles to 300,000,000!! But that would be taking it too far detail wise!

We use the abrasion test BS EN 14157 2004 to establish the suitability of any given stone. I popped down to the lab (Sandberg Consultancy – Clapham www.sandberg.co.uk ) to watch these taking place being the nerd I am. The stone samples are first dried (really dried) and then using a marker the consultant marks the surface before fixing in place. A spinning wheel is pressed against the stone surface at a given pressure and then an abrasive poured into a funel from above falls between the two surfaces. This continues for 1 minute exactly then the stone is removed and the width of abrasion created is measured. The measurment recorded (in millimetres) and this is repeated in this case for six specimens (the recommended number of samples). Interestingly we used 3no polished and 3no honed and it made very little difference, just 0.5mm. A difference all the same.

The result recorded for our Shell Gris was 19.50. This is an excellent result and means the stone can resist 500,000,000 foot traffickings during its life so in fact we can allow the people using the building to nip out for lunch and half of them to pop out for a fag break too.