Canada

Exert Taken From the National Building Code of Canada
 
Section 9.27. Cladding
 
9.27.2.2. Minimum Protection from Precipitation Ingress
 
1) Except as provided in Sentence (2), a cladding assembly is deemed to have a capillary break between the cladding and the backing assembly, where
    a)there is a drained and vented air space not less than 10 mm deep behind the cladding, over the full height and width of the wall (see also Article 9.27.5.5.)
    b) an open drainage material, not less than 10 mm thick and with a cross-sectional area that is not less than 80% open, is installed between the cladding and
    the backing, over the full height and width of the wall,
    c) the cladding is loosely fastened to the backing and behind each cladding component there is a clear air space that is
        i)continuous for the full width of the component,
        ii) not less than 10 mm deep at the bottom of the component, and
        iii) not less than 6 mm deep over not less than 90 mm for every 230 mm of exposed height of the component, or
    d)the wall is a masonry cavity wall or the cladding is a masonry veneer constructed according to Section 9.20.


2) The drained and vented air space, and drainage material described in Sentence (1) may be interrupted by
    a)penetrations for windows, doors and services,
    b) flashing, and
    c) furring, provided the furring does not make up more than 20% of the furred area.
 
3) Where a construction projects over the top of the drained and vented air space described in Clause (1)(a) or over the drainage material described in Clause (1)(b), the air space or drainage material shall not be contiguous with concealed spaces in the projecting construction.
 
4) Exterior walls exposed to precipitation shall be protected against precipitation ingress by an exterior cladding assembly consisting of a first plane of protection and a second plane of protection, where such walls enclose spaces of residential occupancy or spaces that directly serve spaces of residential occupancy.
 
5) Except as provided in Sentence (6), exterior walls exposed to precipitation shall be protected against precipitation ingress by an exterior cladding assembly consisting of a first plane of protection and a second plane of protection incorporating a capillary break, where
    a) the number of degree-days is less than 3400 and the moisture index is greater than 0.90, or
    b) the number of degree-days is 3400 or more, and the moisture index is greater than 1.00.
(See Sentence 1.1.3.1.(1) and Appendix C for information on the moisture index.)