Partition Wall Systems

83 2015). The term component is interchangeably used with module and is also used to signify either complex assemblies of parts or the parts themselves. Kieran and Timberlake mostly use the term module for the latter meaning, while the expression “grand blocks” is used to signify large building components which offer support for “smart modules”. Thus, while the terms are different the concepts behind them are the same.

The fundamental difference between both authors lies in how the decision on the modular framework is made. For Larson this something that is arrived at by industry consensus, while for Kieran and Timberlake this is something that the “tier 1” product manufacturer can decide.

4.4 Negotiating criteria for customizable and disassemble able

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Figure 4-1: Partition wall functional element classification OmniClass 2012 table 21

Partition walls are part of the interior (level 1), interior construction sub-group (level 2), interiors partitions (level 3). The level 4 further disaggregates interior partitions into: interior fixed partitions, interior glazed partitions, interior demountable partitions, interior operatable partitions, interior screens, and interior partition supplementary components. The wall finishes are not included in the interior construction group (level 2) but on the interior finishes group, wall finishes (level3).

From the above classifications is possible to define in general terms the three main interfaces of a partition system: (1) the building structure, either on the floor, ceiling, or walls;

(2) the external envelope; and (3) the internal finishes of the walls.

The above classification strictly positions the interior partition walls as non-loadbearing elements and identifies the locus of disassemble-able walls in its level 4, yet it does not clarify the basis for the functional distinction between the types of level 4. Faria (1996) provides a functional classification of non-loadbearing partitions considering the use of partitions (Figure 4-2).

Figure 4-2: Functional classification of non-loadbearing interior partition wall systems

Separation partitions divide different building functional areas, e.g., different apartments or private and common areas. Distribution partitions divide a specific functional area into several rooms and lining partitions duplicate external walls. Separation partitions are less likely to change since they are the frontier between different owners or levels of control within a specific building and correlate with a legal property status. Conversely, lining and distribution

85 partitions are only subject to the control of the unit owner and thus more likely to change.

Hence, disassemble-able partition systems are particularly suitable for these types of functions.

Although lining partitions can be considered part of the group of non-loadbearing partition systems, it is important to note that these walls have implications on the performance of the exterior envelope and are thus frequently studied in conjunction with external enclosure walls.

A functional classification is useful to characterize the scope of application but does not provide information on the tectonic logic of the partition walls systems. To this end, Faria (1996) proposed a classification based on groups of solutions by tectonic processes divided into 3 main groups: Traditional wood frame partitions; Masonry partitions, light prefabricated partitions (Figure 4-3).

Figure 4-3: Tectonic classification of non-loadbearing interior partition wall systems. Adapted from Faria (1996)

The first group contains all traditional types of on-site assembled partitions such as those traditionally used in 19th century Porto townhouse or the light-wood frame partitions common in North American countries. The second group contains all wall systems composed of unit masonry elements whatever the material type. This class contains hollow ceramic brick walls which are still the most prevalent partition wall system in Portugal. Lastly, the light prefabricated category includes all other types of industrialized partition systems, independently of their disassemble-ability, including those that are digitally fabricated.

For each of these groups, Faria proposes a specific classification based on tectonic criteria mapped to specific solutions. Hence there is a loose relation between the criteria used to classify each group, but the classification is useful for designers to evaluate the range of available solutions in a design process. Considering the scope of the present work, only the latter group is presented (Figure 4-4).

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Figure 4-4: Classification of non-loadbearing interior partition light prefabricated wall systems. Adapted from Faria (1996)

Faria selects four main criteria to classify partition walls: Ease of assembly and disassembly, types of joints between panels, structure type, and wall layer. The latter two categories are subdivided into sub-categories related with the tectonic decomposition of the solutions into layers for each specific function and the type of structural solution.

The ease of assembly category is the critical aspect for disassemble-able systems. The partition systems are subdivided according to the degree they are demountable without damage to the interfaces²². The fixed category includes solutions that cannot be disassembled without significant damage to the partition materials or the supporting structure. Conventional light steel frame solutions are included in this group.

The disassemble-able category includes all solutions that are demountable with negligible damage²³ to the support and whose components can be reused in new configurations. The

22 Faria subdivides the solutions according to 4 categories, fixed, demountable, relocatable, and mobile, yet the difference between demountable and relocatable solutions is purely one of degree of reusability of constituent elements.

23 Damage such as screw/nail holes is admissible as negligible.

87 degree of reusability is related with the durability of the constituent materials, connection types between the components and parts, and modularity. Lastly, the mobile category includes operatable partitions by means of rails or hinges. Both fixed and mobile partitions are outside the scope of the present research.

Disassemble able partitions may exist in any combination of the remaining criteria which constitutes a significantly large number of cases. The reader is directed to Faria (1996) which provides a sufficiently detailed collection of solutions for each criterion.

4.4.1.1 Regulatory Requirements and Guidelines

The performance requirements for building materials and products at the European level are defined by standards issued by the European Committee for Standardization (CEN) and guidelines defined by European Organization for Technical Approvals (EOTA). According to EU Regulation nº305/2011 (Construction Products Regulation, 2011), if a construction product is subject to European norms or tested according to a European technical guideline it must bear the CE marking, it is not required to be subject to further national approvals and can be marketed across the European single market.

EU countries are still responsible to establish their own standards and regulations regarding fire safety, mechanical resistance, stability, environmental, and energy performance applicable to construction works.

Products and materials that are covered by CEN standards, must be tested according to the relevant norm, which sets methods and criteria for assessing and describing the performance, to obtain a Declaration of Performance, and have compulsory CE marking.

Some construction products that are considered innovative, such as internal partition walls, have non-compulsory CE marking. These products can still obtain CE marking by testing if they are covered by an existing European assessment document.

ETAG003 (EOTA, 2012) is a guideline for European technical approval for internal partition non-loadbearing walls. It defines a set of requirements and the respective standard testing methodology and technical evaluation criteria to access the performance of partition walls. In March 2019, ETAG003 was replaced by EAD 210005-00-0505 (EOTA, 2019) which reorganized the classification of the requirements, merging the safety in use and durability and serviceability into a single category called Safety and Accessibility in Use. For briefness, Table 4-3 presents the requirements of the latest technical assessment guideline. These technical guidelines already are sound benchmarks for the structural, acoustic, thermal, hygrometric, and fire safety

88 performance of partition walls. Yet, it is important to detail these aspects for an overall definition of criteria.

Table 4-3: Essential characteristics of the product’s performance

The scope of the guidelines covers partitions walls of several types: frame and panel or composite panels walls, that are fully opaque, partially, or totally glazed. The function of the partition is the separation of interior spaces of a given functional unit, with or without fire safety, and/or acoustic insulation, and/or thermal capabilities. Included in the previous definition of the functions are the cases where a partition serves as a lining to interior or exterior walls or it separates spaces with different floor levels (EOTA, 2019, p. 4).

The guideline defines methods and criteria for testing and assessing the performance of the product for each of the identified characteristics. The compliance with safety against personal injuries by contact is verified by visual inspection of the geometry of the wall, the absence of sharp or cutting edges, and tactile inspection to determine the risk of abrasion. Water vapour permeability may be either tested, deduced from tabulated values, or taken from component specifications of the Declaration of Performance. Thermal inertia and reaction to fire performance are determined from the specific properties of the systems’ materials. The remaining safety, fire safety, acoustic, release of dangerous substances, and thermal resistance requirements are tested using experimental methods.

It is the responsibility of the manufacturer of the partitions to define the scope of application of the partitions and promote the certification process. The testing may only be conducted by certified bodies, accredited by EOTA.

Since, thermal, acoustic, and fire safety characteristics are optional the critical design requirements are Safety in use and Hygiene. At the design stage the fulfillment of hygiene requirements may be foreseen if standard materials which have been subject to approval and normalized testing for application in construction, such as plywood, MDF or cork, are used.

Requirements

Resistance to damage and functional failure from horizontal loads EAD -S1

Safety agains personal injuries by contact EAD -S2

Resistance to damage and functional failure from eccentric vertical loads EAD -S3

Resistance to horizontal linear static loads EAD -S4

Resistance to functional failure from point loads parallel or perpendicular to the surface EAD -S5

Rigidity of partitions to be used as substrate for ceramic tiling EAD -S6

Physical agents EAD -S7 Chemical agents EAD -S8 Biological agents EAD -S9

Reaction to fire EAD -F1

Fire resistance EAD -F2

Release of dangerous substances EAD -H1

Water vapour permeability EAD -H2

Airborne sound insulation EAD -A1

Sound absorption EAD -A2

Thermal resistance EAD -T1

Thermal inertia EAD -T2

Accoustic Thermal

Safety and Accessibility in Use

Resistance to deterioration

EAD 210005-00-0505

Fire safety

Hygiene, health and environment

89 On the other hand, the verification of compliance at the design stage for safety and static performance requirements must be done by simulating the behavior of the designed system according to the testing setup defined in the technical guidelines.

The partitions we are considering are, for the purposes of the guidelines, classified as non-loadbearing, relocatable, solid partitions. Non-loadbearing means that these walls do not transfer forces imposed by the structure and as such its contribution to the overall building stability is not considered. Relocatable means that they can be installed and reinstalled with minimal damage to the structure or itself. Lastly, the walls panels are opaque. These partitions are destined to use category A of Eurocode 1, which are areas for domestic or residential activities where users are expected to have a high incentive to exercise care.