Formalised performance specifications for rainscreen cladding

CIMclad: Formalised performance specifications for rainscreen cladding
"Architect"
CWCT test methods
CWCT CWCT testing
CWCT specification
NBS specification
Generic
Specifications
Tender Documents
for a “generic rainscreen” with:
- the outline layout
- a basic specification (typically making references to
external specifications)
- specific performance requirements
(the level of detail can differ widely)
Contractor Proposal
Contract
Contractors Specification
Typically based on external specifications
with more specific quantitative statements.
For an existing System
- may have a System Certificate
- may be supporting Project Certificates
For an ad-hoc Solution
- may be supporting Project Certificates
Project Certificate Testing House
System Certificate
Arrow =“makes reference to”
may relate to an installation
test, a factory test (or both)
Testing Method Statement
Figure 2: A typical specification route for rainscreen cladding
Rainscreen Contractor
3.2 Performance-related specification clauses
The performance of a building such as its weather tightness (air and moisture penetration resistance,
condensation) relies on the envelope to act as a barrier to environmental elements in order to provide the
required performance. Other performance aspects include: thermal and fire resistance; movement (due to
load, moisture and temperature) and tolerance; structural stability and loading; durability (service life
design); and others (noise, acoustics, corrosion, infestation) including appearance and fit. A summary of
the equivalent performance clauses in the CWCT standard and NBS specification is given in Table 1 while
Table 2 summarises tests for checking compliance. Commentary on the performance clauses vis-à-vis
CWCT standard and NBS specification document is given in Report 3.
July 2001 Page 5 of 5