FLOORING

Appearance and Reflectivity

User satisfaction with floors depends largely on the condition of the top wearing surface. After installation, the surface should be clean and capable of being maintained in this condition. It should be suitable to receive a floor covering if one is not provided under the building contract. In areas where water may spill onto floors, both the effect of moisture on the floor and the ease with which the floor may be cleaned and dried, together with its subsequent rate of deterioration, will need to be considered.

Appearance

The appearance of a floor finish is often considered to be of paramount importance, both in its initial selection and its acceptability for continuing use. The visual acceptability of the various kinds of floor finishes, in the final analysis, is a matter for individual taste and judgement.

Concrete Wearing Surfaces

This sub-section deals only with floors where the concrete is finished to form the wearing surface i.e. to take traffic directly. The surfaces of slabs, which receive no further applied finish, are normally finished by one of two methods:

• power floating
• hand trowelling or power trowelling
• grind and polish concrete

These methods, if applied to specification are capable of providing satisfactory wearing surfaces. Traditionally, plain concrete was used to provide floors in a wide range of buildings e.g. workshops, stores and warehouses. Most plain concrete floors have sufficient abrasion resistance to withstand foot traffic and light to medium loads. (Also see Polished Concrete below).

Wear resistance

Abrasion resistance varies between poor and very good depending on the type of aggregate, mix, curing, finishing etc. Impact resistance is normally good and long-term resistance to indentation very good. Wear resistance is greatly influenced by the quality of finishing and the strength of the concrete to produce a dense, tight surface layer. Good power floating, followed by power trowelling, can greatly enhance the wearing qualities of a concrete floor.

Slip resistance

The slip resistance of smooth concrete surfaces is fair to good, depending on surface characteristics. Surfaces are slippery when wet unless a textured finish is applied or slip resistant aggregates are used.

Control of damp and condensation

Concrete is unaffected by water and can be used, therefore, in wet areas, provided no chemicals are present in the water.

Thermal properties – “Warmth to touch”

Very poor

Fire

Non-combustible and no flame spread.

Polished Concrete

HTC Superfloor™

Concrete, known in Rome by its Latin name concretus, has become synonymous throughout history with strength and durability. HTC Superfloor™ is the revolutionary flooring concept that uses a technique that makes concrete more than just strong and hard-wearing. The technique is as simple as it is ingenious. HTC’s machines and diamond tools grind and polish concrete floors to remove the surface paste and expose the stronger concrete beneath. The result of this process is a stronger, more durable, shiny and beautiful polished concrete floor. The environment and one’s bottom line both benefit too.

Concrete floors deserve better treatment than just being walked on. An HTC Superfloor™ will make one appreciate the advantages of having concrete as an exposed floor surface. Dirty, grey concrete floors are transformed into brilliant, easy to clean, environmentally-friendly and durable polished concrete floors.

New or existing floors

HTC Superfloor™ finish can be used on both existing concrete floors with or without coatings and for new buildings in the construction phase. For existing floors, the final appearance is dependent on how the concrete floor was made with regard to the colour of the cement, the type and amount of aggregate used and how much of the aggregate it is possible to expose after grinding. Existing concrete floors can often be ground to the quality of a HTC Superfloor™ using diamond tools and concrete polishers from HTC. For newly cast concrete floors, the different possibilities for creating an elegant floor are endless.

Beauty comes from below

Floors are an important part of everyday life, in both industrial areas and private residences. But as well as looking good, a floor needs to be functional too. That’s why one will like HTC Superfloor’. The glossy concrete surface is not just aesthetically pleasing – it brings a host of other benefits too.

Strong floor, strong bottom line

HTC Superfloor’” is an extremely economical option for all types of business activities. Compared with traditional methods for concrete floors or epoxy, for example, HTC Superfloor” offers unbeatable durability. The processed construction concrete has an unlimited lifespan, i.e. the same as the lifespan of the building. The initial investment is the same, or lower, than for traditional flooring solutions, but the low maintenance cost and the longer lifespan make HTC Superfloor” the most lucrative investment option. The life cycle cost is about 60% less than for traditional flooring solutions. And using the Twister’” method of cleaning, the floor is simple, environmentally-friendly and cost-effective to maintain.

Polymer Modified Cementitious Screeds

These screeds are commonly used where thin toppings of around 8–10 mm are laid directly onto concrete bases, although they can range in thickness up to 40 mm. They normally have good bond strength to the concrete base and good abrasion resistance. Chemical resistance is enhanced by the incorporation of polymers. (Polymerisation is The chemical process, normally with the aid of a catalyst, to form a polymer by bonding together multiple identical units (monomers))

Aggregates and binders may comprise a variety of materials. The most common aggregates found will be sand and fine granite or other stone chippings like quartz. In addition, shrinkage compensation additives are used to reduce the bond line stresses and minimize shrinkage cracking.

While these screeds are often laid as wearing surfaces, they can be used to receive other floorings. They are useful in making up thicknesses of between 10 and 25 mm, and in forming coves and skirtings.

Appearance

Appearance depends largely on the aggregates, fillers used and colour chosen. Surfaces are sometimes ground to expose decorative aggregates. They can become drab in the absence of suitable maintenance. Bitumen modified cements are usually black or very dark grey. Modified screeds which are grey in colour can easily be mistaken for other cementitious materials not containing polymers.

Strength and stability

Resistance to indentation is usually good, but the bitumen mixes may only give fair performance. Overlatexing can lead to a softer screed with reduced indentation and abrasion resistance. Since many of these floorings are laid relatively thinly, the bond strength to the base can be critical.

Wear resistance

Resistance depends largely on the aggregate or filler, though most mixes will give good performance. Higher proportions of latex in the latex modified mixes will give improved wear resistance up to the point where the material softens.

Slip resistance

The slip resistance of surfaces is normally very good, depending on additives. Bitumen modified mixes are slippery when wet unless a textured finish is applied or slip resistant aggregate used.

Granolithic & Cementitious Wearing

Screeds (Topping)

Standard sand and cement screeds are not usually considered suitable as wearing surfaces. However, if they are laid slightly wetter than normal levelling screeds (i.e. not semi-dry), they can provide moderate abrasion resistance. The addition of small amounts of 10 mm single sized aggregate to the mix will enhance the wear properties and reduce drying shrinkage problems.

Granolithic flooring is still used in residential type projects, where power floating is impractical. A typical example is in the garage.

Granolithic wearing surfaces can be found in two forms:

1. As an integral topping to an ordinary concrete mix, laid before the base has achieved initial set – known as monolithic construction. And usually aided by what is termed as dry shake flooring (see below)
2. As a separate granolithic screed – known as bonded
   screeds and toppings, which are applied to hardened
   concrete floors Standard sand and cement screeds are
   essentially light-duty flooring elements and are suitable
   for the following applications:
   • Wearing surfaces of floors of utility rooms in domestic premises e.g. store rooms.
   • Floors covered with carpets, plastic tiles or linoleum, etc. and subjected to relatively light traffic such as in residential homes and offices.

Note: The concrete on which the granolithic screed or topping is to be laid should be hard and strong i.e. characteristic strength of at least 20 MPa. Weak, friable concrete is not suitable as a base for a screed or topping as the achievement of adhesion between such material and the screed or topping is not possible.

When laid as a topping on fresh concrete (monolithic), thicknesses are about of 15–25 mm. The recommended thickness of bonded screeds and toppings is between 25 and 40 mm. Granolithic screeds exceeding 40 mm are much more likely to debond and become hollow because of drying shrinkage.

Dry Shake Flooring

Dry Shake Flooring Systems are characterized by the application of the dry powder to the surface of freshly laid concrete. The special hydraulic cements and powerful workability aids in the powder release moisture from the concrete. This results in the material hardening at a very low water-cement ratio, monolithically with the base concrete, creating an integral and extremely hardwearing surface.

Dry Shake Flooring Systems are cost effective as they are installed with the main floor slabs by the same concrete flooring contractor. Since there is no separate installation process, they have no effect on the programming of a project.

Appearance and reflectivity

• Some granolithic surfaces may have been coloured by the use of coloured cements or pigments, and some may be of a colour imparted by the colour of the fine aggregate used. Reflectivity therefore depends upon the surface colour chosen, lighter shades like grey give reflectances of around 0.45, with darker shades being around 0.25.

Synthetic Resins

Synthetic resins provide flooring materials, which can be modified to achieve a very wide range of performance characteristics, albeit that such versatility and performance can be expensive. These floorings do provide an enhanced resistance to a wide range of chemicals and being jointless offer, a hygienic solution for buildings in specific industries.

The resins used are epoxy resin, polyurethane, polyester and acrylic (methyl methacrylate), often referred to as thermosetting resins. Except where they are used as coatings, they are always mixed with substantial quantities of aggregates, which include sand, quartz, and carborundum. Resin flooring systems allow the integration of a wide variety of materials and objects, and thus add an individual touch to floors. Be it quartz sand in many colours and particle sizes, or granulated polymers, stone and glass, or many types of flat objects: they can all be integrated into the floor coating and produce amazing results. Even a simple combination of colours can create extraordinary effects. There are no limits to shapes and patterns, and almost any shade of colour is possible.

• Resin screeds – These are relatively stiff mixes with the material being applied by trowel or sledge followed by power trowelling. The mix proportions are often in the range of 1:5 to 1:9 resin: aggregate. The aggregate size can range up to 5 mm and some decorative screeds have even larger aggregates. Because the resin content is rarely sufficient to fill all the pore space between the aggregate particles, these floorings are often finished with a seal coat of the same resin to provide a hygienic surface. Resin floors with careful selection of resin, hardening system and aggregates can provide excellent chemical and abrasion resistance, and be used for very heavy-duty areas. They are most often laid between 4 and 6 mm thick.
• Self-levelling resin floorings – these are very fluid materials, as their name implies. They contain much finer aggregate and provide very smooth non-porous hygienic surfaces. Often laid in the range 1–3 mm thick, they provide excellent floors in clean rooms, pharmaceutical factories, food processing areas etc. these very smooth floorings can be slippery when wet, a degree of slip resistance can be engineered into some types of resin flooring systems.
• Coatings and seals – many resin screed mixes require a final seal or topcoat, which are discussed in this section even though they could be classed as a coating or seal. Others are discussed in the next section – paints and seals.

Appearance and reflectivity

Base resin and hardener systems tend to vary in colour from clear through to white. Most systems are pigmented, with a wide range of colours being available.

Choice of materials for substrate

Synthetic resin floorings can be laid successfully on a wide variety of primed substrates, but concrete is by far the most common. The alkali content of concretes can inhibit hardening of some resins, and high moisture content can inhibit adhesion, so the longer the concrete is left before applying the flooring the better. Some thermosetting resins require the concrete substrate to be below a certain moisture content before they can be successfully laid.

Strength and stability
Results of testing for compressive strength, flexural strength, bond strength and tensile strength are normally available from the manufactures of resin products, which may give the user some indication of relative performance. However, care has to be taken that the resin product is appropriate to a particular application.

Paints And Seals

Floor paints are normally used over very large surfaces as a relatively inexpensive means of improving appearance in the short term. Seals are applied to concrete floorings as a means of surface hardening and to prevent dusting, again as a short term measure. Seals are also applied to a number of different synthetic resin flooring systems as discussed above. In many instances the terms floor paint and floor seal are interchangeable.

Paints and seals are normally categorized as one of the following:

• polymer based emulsions e.g. acrylics
• resin based solvent mixes
• oleo-resinous paints
• one and two-pack polyurethanes
• two-pack epoxies
• chlorinated rubber

Polyurethanes are the type most frequently used. Some preparations are available with fine aggregates to enhance slip resistance.

Concrete seals or surface hardening agents are normally found to be one of the following types:

• sodium silicate solutions
• silico-fluoride solutions
• one and two-pack polyurethanes
• epoxies

Solutions of sodium silicate, magnesium or zinc silicofluoride applied to the surface of a good quality concrete floor will often increase its resistance to abrasion and dust formation. This treatment is of little use, though, if the surface is of poor quality.

Appearance and reflectivity

• Paints are available in a wide range of colours. They can discolour under certain conditions of use.
• Seals can significantly affect the appearance of a floor, especially the pigmented types.
• Polyurethanes on timber give a high gloss finish, which becomes matt where trafficked.

Choice of materials for substrate

As is normal with paint systems, the condition of the substrate has a significant effect on performance. Thin coatings cannot be expected to restore the integrity of pitted worn or friable surfaces; indeed, they will readily detach from the high spots. Seals, too, are often expected to work wonders with dusting surfaces, whereas their capabilities are limited by the condition of the substrate. When timber is resealed, it is normally first sanded. Other floorings, such as linoleum, may be also sealed e.g. with acrylics.

Strength and stability

• Two-pack paint mixes usually produce tougher finishes than one-pack. They adhere by adhesion and penetration. Adhesion is affected by the presence of contaminants such as oils or greases on the surface, leading to selective detachment.
• Sodium silicate and silicofluoride seals act by filling the pores of the concrete or screed, coupled with some chemical reaction with the free lime in the cement to harden the surface. They are not used on timber.

Carpet (Textile)

Textile floorings, or more commonly known as carpets, are one of the more commonly used types of floorings in residential buildings, including commercial buildings like offices, albeit these types of applications also make use of carpet tiles. (For more on carpet tiles see notes at end of this sub-section). Materials used in the manufacturing process include wool and cellulose, and various combinations of synthetic fibres such as acrylics, polypropylene and nylon for piles, with polypropylene, nylon and polyesters used for backings. The variety and qualities is enormous; all that can be explained here is to cite a few of the more common varieties together with some of the materials used and some basic carpet terminology including manufacturing processes.

Fibre bonded carpets, often based on polypropylene or nylon, have become popular. They can offer considerable advantages from the point of view of ease of cleaning, and give excellent abrasion resistance.

The main manufacturing processes for carpets are:

• Woven – the carpet is produced on a loom similar to woven cloth and is a cut pile. Usually many different coloured threads are used and this process allows one to produce complex patterns from predetermined designs. These carpets are usually the more expensive.
• Tufted – the carpet is produced on a tufting machine using a single coloured or sometimes non-coloured thread. If non-coloured thread is used, the carpet will be dyed or printed with a design as a separate process. Modern tufting technology now enables the production of basic geometric patterns. Tufted carpets can be either cut pile, loop pile or a combination of both. Tufted carpets are cheaper than woven carpets.
• Needlepunch – these carpets are more technologically advanced and growing in popularity due to their durability and stain-resistant properties. Needlepunch carpets are produced by electrostatic attraction of individual synthetic fibres together with a series of barbed needles. All the fibres are anchored into a resin backing, giving superb stability with extremely high durability.

The carpet yarn loops have been cut off to create individual yarn ends for a soft, luxurious look and feel. Best suited to those special areas where underfoot comfort is important.

A more durable carpet, the carpet fibre loops are not cut or sheared, so the loops form the carpet surface. Soil tends to stay on the surface, making cleaning easier. Level loop pile has a tight, pebbly surface. Multi-level loops produce interesting patterns that have enhanced soil-hiding capabilities. Textured loops are constructed with loops of slightly different heights, randomly placed.

Carpets are manufactured from either natural or synthetic fibres, or a blend of any, the most common types include:

• Wool or Wool blended with synthetic fibres – 100% Wool has excellent durability and is the only carpet product with a fire rating of one. Blended Wool yarns are used a lot in modern carpet production.
• Nylon – This product is the most popular synthetic fibre used in carpet production. Nylon can be dyed topically or dyed in a molten state otherwise known as solution dying. Nylon can be printed easily and has excellent wear characteristics. In carpets, nylon tends to stain easily because it possesses dye sites on the fibre. These dye sites need to be filled in order to give nylon any type of stain resistance.
• Polypropylene – This polymer is used to produce carpet threads mainly because of its cheaper price, Polypropylene is difficult to dye and does not wear as well as wool or nylon. Carpets made from this fibre are usually only suited for light to medium domestic use.

Carpet grading

Carpets are graded in accordance with the following SANS use classes; classes 1 and 2 are seldom specified, with class 3 being the most commonly specified carpeting for residential applications. (Textile floorings are tested and graded for their suitability to specific areas)

Class 1 – Light Residential
Class 2 – Medium residential
Class 3 – Heavy Residential/ Light Commercial

• Areas where high-energy absorption is desirable
• Domestic rooms
• Corridors subject to heavy traffic
• Playrooms
• TV rooms
• Offices subject to light traffic

Class 4 – Medium Commercial

• Areas subject to heavy traffic and wheel traffic
• Offices
• Shops
• Hotel bars
• Public lounges

Linoleum

Linoleum or as some refer to as ‘Lino’ is a floor covering made from a mixture of linseed oil, resins, cork and wood flour, traditionally adhering to a hessian backing, though other materials have been used as backings in more recent years. Heat treatment then follows to create a tough material, which is consistent throughout its structure and has a smooth surface.

Linoleum is available in sheet and tile form in a range of thicknesses from 2, 2.5 and 3.2 mm though other thicknesses may be available to special order. Linoleum sheeting can be laid with butt joints or grooved joints; where the grooved joints are hot welded with a fully flexible coloured welding rod to provide a homogeneous hygienic sealed finish.

Normally abutments are covered with skirtings or a cover mould. The thinner products can be formed as coves by using formers to which the linoleum is stuck. Linoleum is vulnerable to scuffing in areas of heavy traffic such as at thresholds; some protection, perhaps in the shape of a timber moulding or aluminium extrusion, may be needed.

Adhesives used for sticking down linoleum have been of many varieties: vegetable and casein glues, lignin pastes, gum spirit adhesives, latex cements, bitumen rubber, and tar emulsions and bitumen rubber solutions in petroleum solvents. Not all these materials would now conform to health and safety legislation, or indeed be available. The adhesives most often used are resin alcohol and gum spirit.

Appearance and reflectivity

Linoleum comes in a wide range of colours and is soft, resilient, and easy to maintain, but can suffer from indentation.

Choice of materials for substrate

Linoleum floorings have been laid successfully on a wide variety of substrates. Although the material is flexible, it performs best on a firm base i.e. a concrete sub-floor.

• All subfloors must be tested for moisture content, with a hygrometer reading showing a moisture content of less than 70% prior to installation,
• Where timber floors are used as the sub-floor, they need to be in good condition, with no warping and with nail heads punched below the surface.
• Uneven solid or suspended timber sub-floors may need preparation to meet the required standard.

Strength and stability

• Standard linoleum may not be suitable for use in situations where there is a risk of impact loads from sharp objects and wheeled traffic.
• A toughened form is available, in which the surface is reinforced giving improved resistance to point loads.

Wear resistance

Good.

Vinyl (PVC Flexible/Semi-Flexible)

The development of flexible PVC flooring – frequently referred to as vinyl – has been one of rapid growth since the 1960s. There are vinyl-flooring options for every budget, every décor and every taste. Vinyl is a low-maintenance, high performance flooring option to just about any well-trodden area. Some grades can be used in heavy wear situations and products for many different uses including Healthcare, Electro Static Discharge protection and Safety Flooring, Acoustic Foam flooring for comfort and sound absorption are produced.

Ranges come in a multitude of colours in both directional and non-directional, including luxury vinyl tile products in wood, stone and other natural finish effects.

The tiles and sheets consist of PVC resins, plasticisers, stabilisers and extenders, forming a rubber-like material, which varies in consistency between hard and soft. PVC cannot carry large quantities of fillers without losing its rubber-like properties. The material is calendered to thicknesses varying from 1–3 mm, formed into multilayer sheets as appropriate and left as sheets or cut to size as tiles. Typically, unbacked flexible PVC is available in roll or tile form and backed material usually in roll form only.

Flexible PVC can be laid with butt joints, or it can be hot air welded to form a virtually continuous surface; with some materials, joints can be solvent welded.

Appearance and reflectivity

Since most of the basic materials are light in colour, a wide variety of clean bright colours and marbled effects is available. Seams can be welded, giving an almost unbroken surface. Welding rods can be found in colours that will provide contrasting effects to tiles and sheets or colours can be mixed and matched to suit your requirements.

Choice of materials for substrate

• PVC flooring can be laid on a wide variety of substrates. The most common substrate will be a screed or concrete. Although this type of flooring is flexible, it will be susceptible to movements at cracks and joints in the base leading to rippling
• Subfloors must be smooth, hard, clean and dry before laying commences.
• All subfloors must be tested for moisture content, with a hygrometer reading showing a moisture content of less than 70% prior to installation.
• Timber boarded floors will not usually cause flexible PVC flooring to crack, though any warping will show and movements in the timber may result in rippling
• Existing floors of ceramic tiles may provide a suitable base if a levelling screed or latex underlayment is applied.

Strength and stability

The resistance of unbacked PVC flooring to indentation is good, though the material is soft. The backed type, though, can be cut by furniture feet.

Wear resistance

Normally the wear resistance of these materials is between good and excellent.

Slip resistance

• Very good in dry situations
• Smoother types can be very slippery when wet.
• Special slip resistant grades are available

Rubber

Rubber flooring is available in sheet or tile form, in varying degrees of hardness, and with various forms of surface profiles to enhance slip resistance.

Appearance and reflectivity

• Sheet and tile rubber flooring is available in a wide range of plain or marbled colours.

Choice of materials for substrate

• Rubber flooring can normally be stuck to a flat screed using a contact adhesive or other recommended proprietary adhesives.
• Uneven solid or suspended timber subfloors may need preparation to meet the required standard.
• Where rubber flooring is to be stuck to ground bearing concrete floors/slabs with adhesive, a damp proof membrane must be incorporated into the subfloor.
• All subfloors must be tested for moisture content prior to installation.

Strength and stability

The resilience of rubber flooring can be exploited for a variety of applications e.g. indoor sports.

Wear resistance

Very good

Slip resistance

Rubber flooring is unsuitable for areas around cooking, washing or laundering, or in spaces near entrance doors. It is very poor when smooth and wet unless ribbed or studded.

Control of dampness and condensation

• Although rubber as a material is largely unaffected by dampness, the same cannot be said of adhesives used to stick it to screeds or other substrates. Where rubber flooring is to be stuck to ground bearing concrete floors/ slabs with adhesive, a damp proof membrane must be incorporated into the subfloor.

Jointed Hard Finishes

Tiles; ceramic, natural stone, terrazzo, concrete flagstones and brick pavers.

The floorings dealt with in this section tend to be both hard and durable. The materials include Ceramic tiles, brick pavers, concrete flagstones, natural stone tiles, and terrazzo tiles. The materials described are fundamentally broken down into two specific categories:

• Tiles
• Paving

These two categories are dealt with in separate sections in this publication. However, in order to allow the reader to draw a comparison of these types of materials being used as a flooring surface versus others described in this section, we have covered the basic performance requirements and properties of tiles and paving as one in this sub-section.

The enormous variety in products as described above, in addition, the different types of manufacturing processes make it impossible to cover every type of product manufactured; all that can be done here is to try and provide sufficient information as a guide to facilitate the reader making an informed decision or choice.

Note: For more information please see section on tiling.

Appearance and reflectivity

• Tiles are available in a variety of types, sizes and colours.
• Most manufacturers produce a range of special size tiles to fit awkward spaces, and to form coves, upstands and stair treads.
• When tiles are subject to wide dimensional deviations in manufacture, it should be remembered that the wider the joint, the less apparent will be these variations in size when the floor is laid.
• Clay Pavers are normally available in standard brick size, but with a reduced thickness of 50 mm, with concrete pavers available in many different sizes, shapes and thicknesses; pavers also include special bricks to suit specific functions e.g. a bull nose paver for a pool coping. For more details see: Paving – Materials
• Light shades give reflectances of around 0.45, medium shades around 0.25, and dark shades around 0.10. Remembering many of these products are used externally where high reflectances are not ideal, especially when using a light shade ceramic tile e.g. light grey; which give a terrible glare in direct sun.

Substrates and beddings

• Tiles are normally laid on concrete bases or screeds. If they are laid on timber bases, great care will be needed to accommodate their brittle characteristics.
• Brick pavers and flagstones can be found laid on sand or river-sand beds, or even upon consolidated earth, including concrete bases

Strength and stability

• Thin tiles will be less able to resist impact damage unless they are fully bonded.
• In specifying thin tiles, a balance has to be struck between initial cost and impact resistance. The thinner tiles may cost less but are more vulnerable to impact damage than thicker tiles.
• Loosening or debonding of tiles from the substrate is not necessarily the result of bad workmanship. It could be due to drying shrinkage or moisture expansion of the tiles.
• Brick pavers are used where impacts are expected to be severe. Pavers thicker than the normal 50 mm are available, and, if necessary, improved impact resistance can be obtained by laying the pavers on edge; for further information see: Paving – Materials
• The necessary thickness of screeds to receive different types of floorings, including tiles has been dealt with in the plastering section in this publication; for further information see: Plastering – screeds and toppings

Wear resistance

• Abrasion resistance of these products is good to very good, especially for the harder vitrified or semi-vitrified products fired at high temperatures.
• Impact resistance is normally fair to excellent.
• Resistance to long-term indentation is excellent.
• Where pavers, flagstones and tiles are laid herringbone (pattern at 45°) across the main lines of traffic, they can offer improved resistance to wear from wheeled traffic. This is because impacts on protruding edges are glancing rather than direct.
• Ceramic tiles are normally tested for surface hardness by a MOHS test;
  for further information see: Tiling – Terminology

Timber & Timber Products

Characteristic details

The species of timbers suitable for flooring are too numerous to mention in detail in this publication, with this vast variety available, each floor can be individualized according to specific needs or tastes, with each wood species having its own qualities in terms of hardness, grain and colour. With genuine wood, each plank has its own unique grain. In addition, some species lend themselves to staining, while others are most beautiful in their natural tone. Timber can be categorized in two botanical groups:

• Hardwoods are the species, which belong to the botanical group angiosperms, and can be described as wood from broad-leaved, usually deciduous trees. Hardwoods are often used in decorative applications, but are not always hard.
• Softwoods are the species, which belong to the botanical group gymnosperms. Softwoods often contain resin, which makes them waterproof. Softwoods generally have less moisture than hardwoods, are easier to work, usually less decorative and used for utility, not appearance. Small firm knots are normally acceptable in softwoods intended for use as the final flooring, but are not acceptable in hardwoods. Heartwood is the wood that has finished growing, usually the best timber in a log, darker and more durable than sapwood. Sapwood is the outer woodof a tree, which before felling was living tissue and is softer and paler in colour than the heartwood although not always weaker than the heartwood.

Allowing for movement

Wood and wood based panel products are subjected to dimensional movement as moisture content changes, and provision must be made for this movement to take place without disrupting the flooring. Movement is normally accommodated at the perimeters of rooms where skirtings cover the edges. Vulnerable areas are at door thresholds and staircase landings.

It is the relative atmospheric humidity (RH) that is in principle completely decisive for the appearance and movements of the wooden floor and, in the long run, also its function. A wooden floor, which is subjected to very low or very high atmospheric humidities, will shrink and swell beyond the limits indicated by the manufacturers. It is important to understand that these limits are set not only from an aesthetic viewpoint.

Appearance and reflectivity

• The species of timber is often selected for its appearance, provided durability can be predicted.
• There are too many species for meaningful comment on appearance.
• The quality of the wood is crucial to the appearance of the finished floor, though, as a natural material, it is inevitable that there will be differences in grain and colour between units. Indeed, it can be argued that it is this variability, which gives a wooden floor much of its character.
• In general, some of the paler coloured woods, such as maple, tend to bleach slightly on exposure to sunlight. They may yellow too. Other woods, such as iroko and afrormosia, tend to darken.
• Sapwoods and heartwoods tend to change colour at different rates.
• It should be remembered that re-sanding old wood floorings would often reveal a quite different colour from that to which owners have become accustomed.

Choice of materials for substrate

Timber flooring can be laid on a wide variety of substrates. The most common substrate will be a screed or concrete base where boards are laid normally to form the deck, whereas strip flooring is laid normally on battens on a concrete or dense screeded base. Where the substrate is solid, it must be level and dry, and an effective damp proof membrane is essential.

Wear resistance

• Wear resistance depends on the species and structure of the timber. Although surface finishes, especially those based on polyurethanes, can slow down the rate of wear of a timber surface, they have only a marginal effect on hardwoods.
• Abrasion resistance is fair to very good for unprotected hardwoods and poor to fair for unprotected softwoods.
• impact resistance is fair to very good for hardwoods and poor to fair for softwoods.
• Long-term indentation is fair to very good for hardwoods and fair for softwoods.
• Modern layered floorings have a lacquered finish, which protects the wood, and allows the natural beauty of the wood grain to be revealed and provides a strong, durable surface that will last for years.
• Most laminate floors are manufactured with a highly abrasion-resistant overlay, providing a durable surface, which will last for years (also see utilization class under laminate floors).

Laminate Floors

Laminate flooring is essentially a flooring system that is floating (glueless) with all systems having a click in joint that connect the planks together. Some manufacturers also produce ranges that can be installed completely glued to the subfloor, should this be the preferred way of fixing we suggest you confirm these details with the technical department of the chosen manufacturer.

Laminate floors are manufactured in two ways:

• High-Pressure Laminate (HPL) manufactured at 9653 kPa. (1400 psi)
• Direct Pressure Laminate (DPL) manufactured at 2070 – 3448 kPa. (300-500 psi)

Even though both laminate types are made of the same basic materials, the pressure used in the manufacturing process helps determine both hardness and performance.

High-Pressure laminates have the following advantages:

• Better impact resistance – no denting
• Better design clarity – higher sheen levels
• Better static load capacity – no dimpling
• Higher in-carton product integrity – less damage in handling, no chipped corners
• Better, wear resistance – fewer scuffs and scratches

Moisture

A moisture or vapour barrier installed below the laminate flooring is always recommended, especially when the flooring is to be laid directly onto a new or recently cast concrete sub-floor. Many manufactures also produce ranges that have a moisture resistant core, available in different classes, for areas requiring added water protection as well as those areas where wet cleaning methods are used e.g. a kitchen. (This however, does not promote the use of excess water and is more an added protection against the use of excess water and spillages).

Layered Wooden Flooring (Engineered)

The construction of layered wooden flooring is made up as follows; the wear layer or top layer on each plank is a selected
hardwood veneer. The middle layer consists of a high-density material, using a high-density fibreboard or plywood. The
bottom layer is made of pine, other softwoods or plywood, which allows the construction to perform flawlessly in a variety of
climates and environments. The flooring is usually finished with a factory pre-finished acrylic coating.

Standards

The European standard for laminate floorings EN-13329 creates transparency with regard to the following issues:

• Definition of the term “laminate flooring”
• Product tolerances
• Describes the minimum standards and establishes test standards to set utilisation classes (see below)

Utilisation classes

There are six utilisation classes in total (21, 22, 23; 31, 32, 33). According the euro standard 685, the respective classification of a product is documented by means of pictograms and a two digit numeric code.