the capacity of the ceramics to maintain in time its initial features, the technical function and aesthetics must find the right balance.

Transcription

1 JULY/AUGUST 011 JOINTS IN CERAMIC TILING S U M M AR Y: Introduction 1 What is a joint? Construction type of joints -3-4 Field mounted joints 5-6 Applications 6 Prefabricated joints 7 Experience teaches us that, during the planning phase, in the realization of ceramic tiling it is very important to assess the installation of the dilatation joints. To guarantee the durability of the ceramic surface, suggesting with the term durability the capacity of the ceramics to maintain in time its initial features, the technical function and aesthetics must find the right balance. OTTOSEAL S100 and S105 are two silicon sealing products with matching colours for cement sealing Litochrom 1-6 and 3-15 and the entire series of colours of epoxy sealing Litochrom Starlike. Used for sealing joints connecting coatings and bathroom fittings and to seal of dilatation joints. Therefore we would like to provide indications for a correct execution of the joints in ceramic tiling and illustrate the products which Litokol proposes to satisfy both needs.

2 What is a joint? A joint can be considered a cushion for the movement of ceramics, which supports the dilatations, contractions and various stimulus which the material is subjected to due to the variation of temperature, structural movement, dynamical stimulus, traffic vibrations, etc In the sector of ceramic laying, there are four different types of joints identified: Structural joints A structural joint represents the interruption of the continuity of the work. This detachment is sometimes necessary to: avoid that the variation of temperature causes tension; allow free dilatation of the pavement; avoid earthquake damage. Fraction joints Fraction joints must be made to support every 0-5 m² by the means of a mechanical cut which must concern 1/3 of the depth. To these joints the continuation of other tiling joints must correspond. Dilatation joints Dilatation joints must be predisposed to subdivide extended tiling into smaller sections which in average must not exceed 9m² (3x3 linear meters) in the case of external area and 5m² ( 5x5 linear meters) in case of internal areas. Perimetric joints Perimetric joints must always be predisposed along the perimeter of the tiling, where the tiling confines with walls or other elevations from the plane such as columns and stairs, and interest the width of the support and of the ceramic covering. Type of construction joints Joints are divided into two categories: field mounted joints and prefabricated joints. Field mounted elastic joint with silicone sealing of the same colour of gap. Prefabricated movement joints available in different materials such as PVC, brass, aluminium, steel and different internal finishing's.

3 Sizing of the fractionation and dilation joints For correct sizing of the joints in exam, the greatest possible size variations of the tiling will have to be considered. In particular we must consider : materials dilation coefficient (support and tile) tile type and format; lay out design; adhesives and leak materials used for the lay out ; environmental conditions (thermal variation, humidity conditions) ; distance between fractionation and dilation joints. Thermal dilation means the length variation of an element caused by a variation of its temperature. The lengthening entity of a material depends on a specific constant of the material, also called linear dilation coefficient or thermal dilation coefficient. To calculate the lengthening of a material based on a certain temperature variation, it is necessary to know the linear dilation coefficient which is indicated with the letter α. This dilation coefficient describes in which measure a solid body lengthens or shortens in ratio to the overall length, following a 1 C temperature variation (normally it is expressed in 1K when a 1K thermal variation corresponds to a 1 C thermal variation). In case of ceramic tiles, the movement between the joint borders can be calculated as follows: ΔL = LxαxΔt where: ΔL : movement between the joint borders L : distance between the joints α : dilation coefficient Δt : expected temperature range Example: in an exterior flooring mad up of a cement based screed with thermal dilation coefficient α=0.01 mm/m/k and porcelain grès tiles with α=0.007 mm/m/k where the distance between the joints is 5 meters and with Δt expected thermal variation of 50 C, one will have a ΔL lengthening respectively of: ΔL cement support = 0.01x5x50 = 3 mm ΔL porcelain grès = 0.007x5x50 = 1.75 mm Obviously the contractor will have to account for the maximum possible movement meaning that of the cement support. Once the maximum possible movement is known, it is now possible to calculate the width between the joint borders with the following formula: L = ΔL/m where: L : minimum width of the joint which allows the sealant to deform in elastic field ΔL : movement between the joint borders m : operational lengthening of the sealant by looking at the previous example and considering use of an elastomeric sealant with a 5% operational lengthening, the minimum width of the joint will be: L = 3/0.5 = 1 mm The following graph allows to simply and quickly determine both the movement of the joints and the minimum width between the borders of the joint when distance between the joints, foreseen temperature range and percentage of sealant movement are known. This graph can be used for structures made up of concrete or for materials with similar dilation coefficients (α = mm/m/k).

4 Necessary joints width in mm. Movement of joint in mm. 4 GRAPHIC METHOD FOR QUICK JOINT SIZING PERCENTAGE OF OPERATIONAL SEALANT LENGTHENING Distance between joints in m.

5 TILE 5 Fig. 1/A Permetric joint ELASTOMER SEALING CEMENT OR EPOXY SEALING Fig. 1/B Fraction joint ELASTOMER SEALING Field mounted joints Field mounted fraction, dilatation and perimetric joints, are prepared directly on site and are made of a spacing filled by a compressible material and on surface by a elastomer sealing which can dilate and compress itself (fig.1/a - 1/B): TILE COMPRESSIBLE MATERIAL (LITOSIDE) Photo 1 Fraction joint For the realization of this type of joint Litokol proposes: Litogap: compressible cord in closed cell polyethylene available in 6, 15, 15, 0, 5, 30 mm diameters. Litoside: band of expanded polyethylene for the realization of perimeter separating joints. Elastomer sealing Collaborating with leading company OTTO- CHEMIE, Litokol can supply silicone sealing with matching colours to the cement Litochrom 1-6 sealers and the entire epoxy Litochrom Starlike sealing series (Photo,3), obtaining elastic joints in the same colours as the gaps. These silicone sealers can be used internally, on pavements and walls, in bathrooms, on bathtubs, sinks and showers. To seal natural rock use neutral reticule sealers instead such as Litosil Neutro. Elastic joint realized with silicone sealing Of the same colour of the gaps Elastic joint realized with silicone sealing Of the same colour of the gap photo photo 3

6 FIELD MOUNTED JOINTS 6 Water-resistant joints on balconies and terraces. In this case the Litoband Maxy sealing band must be entered by reversed Omega inside the joint and drowned at the extremities between the two hands of the water-resistant membranes Elastocem e Coverflex (photo 4). In this case use a low modulus polyurethane sealing product such as Polyurethane Litosil Photo LITOGAP - FIBER- GLASS NET 1 - COVERFLEX 5 - Elastic joint realized with silicone sealing POLURETHANE LITOSIL 3 - LITOBAND MAXI 1- ELASTOCEM Application First of all clean the joint and the side of the tiles from dust, small rubble, etc. If the joint is humid you must dry it or wait until it is completely dry. Then the ceramics or natural rock positioned on the side of the joint, must be protected by applying a tape band along the corners of the joint. At this point you may expel the sealer from the cartridge using a special pistol with the correct angle and with a continuous application. The surface finishing can be executed with special metal or plastic spatulas.

7 PREFABRICATED 7 Prefabricated joints are profiles industrially produced and composed of different materials (PVC, aluminium, steel, brass) according to its use. Generally for light weight traffic, joints in PVC are used, whilst in intense heavy weight traffic, aluminium profiles or steel profiles are used. All these types of prefabricated joints are composed of two internally L shaped anchorage elements in which a compressible material is inserted, available in different colours. Litokol has been distributing Genesis profiles for many years, all the types of prefabricated joints with different widths according to the materials used, if ceramic or stoned, are comprised in the series. The Genesis movement joints are classified in three categories, light, medium, heavy according to the level of resistance needed and level of protection that they can offer. The Genesis movement joints are available in different materials such as pvc, brass, aluminium and steel and with different finishing's inside. MLC Compression joint PVC MLB Compression joint PVC - Light traffic MSA - MSI Movement joint Aluminium Optimax line - Intense traffic MMA Movement joint Aluminium MHB Movement joint Brass - Intense traffic MHS Movement joint Steel - Intense traffic LITOKOL S.p.A. Via G. Falcone 13/ Rubiera (RE) Italy Tel: Fax: info@litokol.it