History of Paving Jointing - Online Shop
The Origin & Development of Cement & Cement based Jointing
Since pre-history, whenever stone paving was first used and developed as a durable system and solution for hard surfacing in, around, and between urban populations, other than in the selection of the best types, sizes, and build-up of stone, the first major advancement was in paving joint technology. This development was made not by the Romans, as often claimed, but much earlier and by the Minoans about 6,000 years ago, specifically it is believed, to ensure level surfaces for their pathways, roads, and hard standings, without trip hazards, and with ease of water run-off. The suitably filled joints ensured a smooth transition for the early wheeled and rolled traffic, etc., so the requirements in this respect were not unlike they are today.
This first huge technological step was made with the Minoan engineers’ development of a uniquely adaptable stone bedding and joint filling material that was a basic pozzolanic mortar.
Roman Road across Blackstone Edge Rishworth Moor, East of Littleborough, Greater Manchester in England
The raw materials for this were widely available to them because of the island’s volcanic past, as this type of mortar and this paving jointing application was originally invented on what is now modern Crete. This is also seen as the first and original creation of the pozzolanic building materials now collectively known as cementitious materials - concretes and other cement mortars (‘Con-Crete’ – You see the connection!).
Since this time the technology spread and there have been many developments in the types and sizes of stone used as paving elements, as well as in the mortars used for bedding and jointing them. The areas of use and the exposure in these paved areas has also continually developed and become more aggressive and severe, especially in terms of weathering in harsher climates than around the Mediterranean, like the UK. Today, and especially in town centres and market squares etc., but also on domestic driveways, our natural stone and concrete paving can also have far heavier loadings from vehicular traffic, plus more onerous chemical exposure from spillages, as well as de-icing salts for example.
To counter this problem, at various times in history, different ‘bituminous’ (bitumen = from oil, pitch / tar = from wood or coal distillation) materials have been used for paving jointing, and historically this technique was developed and used to make the joints waterproof, and/or resistant to leaching and wash-out by water erosion.
Paving Jointing with Bitumen / Pitch / Tar Materials
Bituminous bitumen and/or pitch- / tar-based materials (hot and cold applied) have traditional natural stone sett (square edged) and cobbled (rounded) paving for highways, and public areas such as market squares, the paving joints were minimum 100mm to 200mm deep, where there was and is far less thermal variation and therefore bituminous materials have more stability and maintain watertightness. These deep joints were sometimes part-filled with stone chippings, then the interstices filled, and the joints topped off for minimum 100mm with the bituminous materials. These have proved extremely durable in historic areas for the past 300+ years or so, and as a result there are many areas of ‘pitch paving’ that still exist in some heritage areas, especially where the paving and its bituminous based jointing, also has an important waterproofing function, such as over below ground culverts, vaults and other below ground structures.
In new construction or complete replacement works, any such waterproofing requirements can be achieved far quicker and easier by engineered waterproofing with modern materials. Therefore, the installation and repair of bitumen / tar based paving jointing products is generally used only when required for heritage and conservation reasons, and the application should only be done by the limited number of such specialists, otherwise this can be very messy and more trouble than it is worth these days, when good alternative methods of waterproofing and jointing are available.
Paving Jointing Development in the UK
-
Minoan Roads in Crete
-
c3500 BCE-Sandstone and Basalt with Gypsum Clay jointing
-
Roman Road - the Appian Way from Rome to Brindisi
-
Roman Road in Pompei with small white stones for night visib
There is some argument about the arrival of paved surfaces in the UK, which are generally credited to the Romans from the first century AD, though recent archaeological work has apparently discovered several earlier iron-age paved roads which significantly predate the Roman arrival. Stone paved roads, with some form of binder/ filler in the joints would always have been far more efficient for wheeled traffic that is for sure, whenever the concept landed in these islands. Certainly, the major expansion of paved roads across most of the UK, began with the arrival and logistics requirements of the Roman army, who embarked on around 300 years of road building programmes.
Today, all around the UK and indeed the rest of the modern world, cement-based (cementitious) materials are still the most widely used paving bedding and jointing materials. Nowadays, these usually include special cements and/or polymer modified cement mortars, with prebatched and prebagged materials used on many sites to reduce the potential for site batching errors on almost all types of paving. However, modern construction time and cost pressures, skills shortages, and as always in the UK, the wonderful, and very un-Mediterranean British Weather, also all combine to create some serious disadvantages for cement paving jointing that we review in the following pages. These variable and often damp site conditions, plus time pressure s on completion and opening dates, also mean that cement and other paving jointing technologies, can have distinct advantages and/or disadvantages, giving limitations that are not always fully understood or as well-known as they should be. We will cover and expand on all of these in the following pages of this website.
For more advice or assistance with your specific paving project, please call 01257 266696 for FREE Expert Advice, or email: sales@nccstreetscape.co.uk