movement joints with special performance

MOVEMENT JOINTS WITH SPECIAL PERFORMANCE

Joints with special mechanical performance

It is about structural or intermediate movement joints in ceramic floorings subject to non-exclusively pedestrian traffic and where important dynamic loads are anticipated. This type of joints should obligatorily include metal –preferably stainless steel– profiles to protect both the sealing material and the edge of the adjacent tiles. Sealing shall be present between these profiles and between profiles and tiles. The metal profiles shall be welded to the reinforcement of the load distribution layer with which they form a whole system. Figure 1 shows a movement joint with metal reinforcement anchored to the load distribution layer reinforcement.

In other cases, when requiring both high elasticity and high mechanical compression and abrasion resistance, a specific butt strap shall be placed over the infill material.

Figure 1

Movement joints · Special joints 1 Movement joints with special performance

Choosing special prefabricated movement joints systems

Below we show some aluminium movement joints, resistant to high load rolling action, such as fork lift and pallet trucks and lorries, extracted from the MIGUA® catalogue by MECANOGUMBA.

Profiles for structural and intermediate joints in floors with very high live and dead loads.

Profile for structural and intermediate movement joints in floors with high live and dead loads.

Control and field division profile

Selection of joints can be made with the help of the chart below.


Initial criteria (predimensioning) for the selection of MIGUA® joints in floors. Shopping malls. INTERIORS.

TIPO DE TRAFICO

Area Type of ceramic tile Thickness Anchoring

(1) Levelling floor Width to cover Pedestrian Pallet forks Fork lifts Model Proposed (2)

Sales Area Granite-Terrazzo 30 to 40 m/m Received NO Up to 30 m/m YES YES YES FS 50/5000

Sales Area Granite-Terrazzo 30 to 40 m/m Received NO Up to 50 m/m YES YES YES FS 75/6200

Sales Area Granite-Terrazzo 30 to 40 m/m Bonded YES Up to 30 m/m YES YES YES FS 50/5000

Sales Area Granite-Terrazzo 30 to 40 m/m Bonded YES Up to 50 m/m YES YES YES FS 75/6200

Sales Area Stoneware tile Up to 20 m/m Bonded YES Up to 30 m/m YES YES YES FS 50/5000

Sales Area Stoneware tile Up to 20 m/m Bonded YES Up to 50 m/m YES YES YES FS 75/5200

Mall Granite-Terrazzo 30 to 40 m/m Received NO Up to 30 m/m YES NO NO FV 35/5000

Mall Granite-Terrazzo 30 to 40 m/m Received NO Up to 50 m/m YES NO NO FP 55/5000

Mall Granite-Terrazzo 30 to 40 m/m Bonded YES Up to 30 m/m YES NO NO FV 35/5000

Mall Granite-Terrazzo 30 to 40 m/m Bonded YES Up to 50 m/m YES NO NO FP 55/5000

Mall Stoneware tile Up to 20 m/m Bonded YES Up to 30 m/m YES NO NO FV 35/5000

Mall Stoneware tile Up to 20 m/m Bonded YES Up to 50 m/m YES NO NO FP 55/5000

Note: In the FS (metal) series, we should check that the model proposed can bear the load it will be subject to. (1) Form in which the tile is bonded or received (2) The height of the joint to use shall be determined in accordance with the circumstances (difference of height between slab and flooring, and others) of the specific

building work. Equivalences in dimensions between other MIGUA® joint series and those proposed in the chart above. FS 50/... FV 35/... FG 35/... FM 35/... FS 75/... FP 55/... FP 55/... NI FM 60/... ES 60/... FP 60/... FV 35/... FG 35/... FM 35/... FS 50/... FP 55/... FP 55/...NI FM 60/... ES 60/...


Prefabricated structural joints installation process

Let us now take a look at the joint cover installation process for intermediate and structural movement joints in floors aimed at the installation of modular elements such as tiles. It is advisable to follow this installation process when dealing with movement joints in floors where tiles joined to the substrate via cementitious adhesives form the flooring. The thickness of such cementitious adhesives, which are applied with a trowel, is between 2 and 3 mm approximately. Different types of adhesives shall be used according to the material used in the creation of the tile – ceramic, terrazzo, natural stone, linoleum, PVC, etc– The installation process envisages the following stages:

• Floor screed: Generally, flooring shall be adhered on a regularizing screed with a variable height, which may range between 5 and 8 cm. The installation of this screed over the compressive deck layer is an almost unavoidable condition for guaranteeing the right flatness of flooring.

• Boxing: An installation area shall be created, pouring the floor concrete or

mortar, using formwork (usually with wooden board). The aim is to obtain a box with the right dimensions according to the MIGUA® profile to install. It is advisable to consult the MIGUA® system catalogues in order to define such dimensions.

• Pre-regularisation: If necessary, burrs in the deck concrete shall be removed

with a Hilti chisel drill hammer.

• Cleaning: With spatula or trowel.

• Lost formwork: According to the joint width, we shall use very compressible material, e.g. cardboard or EPS. Little compressible material like wood or metal, as well as shapeless materials like paper and plastic bags should not be used.

• Sweeping and washing I: For cleaning the joint area. With a handleless brush

and watering can.


• Provisional supplement: With trowelfuls of mortar or Miguplan mechanisms every 80 to 100 cm, at both sides of the joint.

• Levelling and aligning: Using a ruler and a level, a measurement is made for

each element – i.e. every 80 to 100 cm– acting on the supplement elements (mortar or Miguplan). Aligning is carried out with a gage, taking as a reference the alignment of tiles or reference cord.

• Washing II: For cleaning and preventing dehydration of the supplement

mortar under the joint wing. It can be carried out with a watering can, for instance.

• Mortar pouring: Non-shrink self-levelling mortar, Bettogrout or similar type,

is poured into the joint. This mortar bed shall be thick enough so that the top of the MIGUA® joint wing plus the height of this joint give the level of the finish ceramic flooring.

• Drying: Mortar shall be left for drying for 24 hours.

• Fastening: Wings of the MIGUA® joint are fastened to the mortar base with

fastening plugs every 30 cm at both sides (seven units per linear meter, more or less). Such plugs can be MSA M-6 bolts or S-8 plugs plus screw and washer.

• Top filler: Bettogrout or similar mortar is poured over the joint wing and left

for drying for a shorter or longer period of time, according to the type of adhesive we shall be using in the installation of ceramic tiles.


• Protection: If permanent flooring is not executed immediately after mortar

has been poured as shown above, the joint must be protected to prevent it from being damaged before ceramic tiles are installed.

• Finish: Flooring should be installed as soon as possible so that the MIGUA®

joint acts as flooring reference and the ceramic flooring remains at the same height as the joint. The complete installation sequence is shown below (1 to 6)

For guiding purposes, below we include the most usual consumptions and performance for the installation of MIGUA® joints by MECANOGUMBA (FV-FG-FP 55- FS 50-FS 75, etc.):

- Infill mortar: 15 to 25 Kg/ml (4 or 5 litres of water per sack of 25 kg)

- Installation performance: Data to origin, and taking into account that the joint installer is not the same person as the one installing the ceramic tiles, for some 400 ml: 1 to 1.50 hour/man per linear meter, for teams of two/three workers.


Joints with special chemical performance

In the so called anti-acid floorings, highly resistant to chemical attacks, movement joints require the use of special materials and conditions for obtaining the chemical tightness of the joint. Usually, below the bonding material a protective membrane is installed; such membrane shall require a construction solution at the height of the movement joint. This protection is obtained by using a flexible metal ring and a sliding rigid plate, as well as with a metal strap to keep the bonding material unified at the height of the movement joint. Figure 2 shows a structural movement joint with the layout described.

Figure 2 1. Concrete base. 7. Ceramic tile. 2. Protecting membrane (high chemical resistance). 8. Adhesive. 3. Flexible metal ring. 9. Grout. 4. Sliding rigid plate. A. Bonded surfaces. 5. Metal strip for keeping adhesive cohesion. B. Unbonded surfaces.

6. Elastic sealant.

Unless the floors or compression layers of the slab suffer from cracking, waterproof membranes, resistant to chemical attacks, are usually installed by applying one or two layers of a epoxy compound (furanic resins are used in the USA). If we are using a cementitious adhesive as bonding material, the still fresh epoxy resin is covered with silica aggregate. Sheet membranes with the chemical resistance required to face potential attacking products should be used on cracked or potentially unstable structural backgrounds. The aim of chemical waterproofing is that at least structural elements are not damaged by attack. Obviously, tiling and grout between tiles give shape to the first protection system. Sealants in movement joints are also selected according to their chemical resistance to specific products and to the maximum concentrations of these products depending on the practice conditions the flooring shall be subject to.


Concrete joints

Both natural joints produced by the sequential filling of a concrete flooring, between consecutive pourings, and the joints mechanically cut to channel the cracks produced by curing in a large flooring, shall be treated like structural joints on which the corresponding movement joint must be installed.

The cut in the flooring shall have been made prior to the beginning of the tiling installation process. This type of joints shall be clearly marked by the project management, hence the tiling subcontractor shall then find either the cuts marked or just a simple groove of a concrete joint (also known as cold joints) already prepared for subsequent works.

As we have indicated above, this type of joints shall receive the same treatment

as structural movement joints and the execution process shown in the previous section shall be the pattern to follow. Figure 3 shows a concrete joint and a joint obtained via mechanical cutting.

Figure 3


Drains and wastepipes

Especially in industrial ceramic floor tiling subject to non-exclusively pedestrian traffic, drains require some construction features that guarantee, on the one hand, that both drain and ceramic tiles are mechanically protected, and on the other hand, the full tightness of the drain. Although this subject shall be dealt with again in industrial paving, below we include a picture showing the layout of a movement joint between the floor and the initial part of the device forming the drain outlet (Figure 4). This layout may be considered universal for any type of drain, varying the construction features according to the tightness of the drain and of the multilayer system that converges in it.

Figure 4


movement joints with special performance

Documents