Part H2 Damp and weatherproofing

The Objective is to—

1. safeguard occupants from illness or injury and protect the building from damage caused by—
   1. surface water; and
   2. external water entering a building; and
   3. the accumulation of internal moisture in a building; and
   4. discharge of swimming pool waste water; and
   5. rising damp; and
2. protect other property from damage caused by—
   1. redirected surface water; and
   2. the discharge of swimming pool waste water.

A building including any associated sitework is to be constructed in a way that protects people and other property from the adverse effects of redirected surface water.

A building is to be constructed to provide resistance to moisture from the outside and moisture rising from the ground.

Adequate means for the disposal of swimming pool water and drainage is to be provided to a swimming pool.

(1) Surface water, resulting from a storm having an annual exceedance probability of 5% and which is collected or concentrated by a building or sitework, must be disposed of in a way that avoids the likelihood of damage or nuisance to any other property.

(2) Surface water, resulting from a storm having an annual exceedance probability of 1% must not enter the building.

(3) A drainage system for the disposal of surface water resulting from a storm having an annual exceedance probability of—

1. 5% must—
   1. convey surface water to an appropriate outfall; and
   2. avoid surface water damaging the building; and
2. 1% must avoid the entry of surface water into a building.

A roof and external wall (including openings around windows and doors) must prevent the penetration of water that could cause—

1. unhealthy or dangerous conditions, or loss of amenity for occupants; and
2. undue dampness or deterioration of building elements.

Moisture from the ground must be prevented from causing—

1. unhealthy or dangerous conditions, or loss of amenity for occupants; and
2. undue dampness or deterioration of building elements.

A swimming pool must have adequate means of draining the pool in a manner which will not—

1. cause illness to people; or
2. affect other property.

(1) Compliance with H2P2 for weatherproofing of an external wall is verified when—

1. a prototype passes the procedure described in (2); and
2. the external wall—
   1. has a risk score of 20 or less, when the sum of all risk factor scores are determined in accordance with Table H2V1a; and
   2. is not subjected to an ultimate limit state wind pressure of more than 2.5 kPa; and
   3. includes only windows that comply with AS 2047.

(2) The test procedure referred to in (1)(a) must be as follows:

1. The test specimen is in accordance with the requirements of (3).
2. The test procedure is in accordance with the requirements of (4) and (5) as appropriate.
3. The test specimen does not fail the criteria in (6).
4. The test is recorded in accordance with the requirements of (7).

(3) Test specimen: The test specimen must incorporate—

1. representative samples of openings and joints, including—
   1. vertical and horizontal control joints; and
   2. wall junctions; and
   3. windows or doors; and
   4. electrical boxes; and
   5. balcony drainage and parapet flashings; and
   6. footer and header termination systems; and
2. for a cavity wall—
   1. a transparent material for a proportion of the internal wall lining (to provide an unobstructed view of the external wall cladding) with sufficient structural capability and similar air tightness to resist the applied wind pressures; and
   2. a 15 mm diameter hole in the internal wall lining below a window.

(4) The test procedure for a direct fix cladding wall or unique wall must be as follows:

1. Apply 100% positive and negative serviceability wind pressures to the external face of the test specimen for a period of not less than 1 minute each.
2. Apply static pressure of either 300 Pa or 30% serviceability wind pressure, whichever is higher, in accordance with the water penetration test procedure at clause 8.5.2 of AS/NZS 4284.
3. Apply cyclic pressure in accordance with—
   1. the three stages of Table H2V1b; and
   2. the water penetration test procedure at clause 8.6.2 of AS/NZS 4284.

(5) The test procedure for a cavity wall must be as follows:

1. Apply 100% positive and negative serviceability wind pressures to the external face of the test specimen for a period of not less than 1 minute each.
2. Apply static pressure of either 300 Pa or 30% serviceability wind pressure, whichever is higher, in accordance with the water penetration test procedure at clause 8.5.2 of AS/NZS 4284.
3. Apply cyclic pressure in accordance with—
   1. stage 3 of Table H2V1b; and
   2. the water penetration test procedure at clause 8.6.2 of AS/NZS 4284.
4. To simulate the failure of the primary weather-defence or sealing, the following procedure must be applied to the test specimen:
   1. Insert 6 mm diameter holes through the external face of the cavity wall in all places specified below:
      1. Wall/window or wall/door junctions at ¾ height.
      2. Immediately above the head flashing.
      3. Through external sealing of the horizontal and vertical joints.
      4. Above any other penetration detail not covered by (A) to (C).
   2. Repeat the static and cyclic pressure tests of (b) and (c).
   3. Within 30 minutes of the completion of (ii), remove the internal lining of the cavity wall and check for compliance with (6).
   4. With the internal lining removed, apply a final static pressure test at 50 Pa for a period of 15 minutes.

(6) Compliance:

1. A direct fix cladding wall and unique wall are verified for compliance with H2P2 if there is no presence of water on the inside surface of the facade.
2. A cavity wall is verified for compliance with H2P2 if there is no presence of water on the removed surface of the cavity, except that during the simulation of the failure of the primary weather-defence or sealing, water may—
   1. transfer to the removed surface of the cavity due to the introduced defects (6 mm holes); and
   2. contact, but not pool on, battens and other cavity surfaces.

(7) Test report — The test report must include the following information:

1. Name and address of the person supervising the test.
2. Test report number.
3. Date of the test.
4. Cladding manufacturer’s name and address.
5. Construction details of the test specimen, including a description, and drawings and details of the components, showing modifications, if any.
6. Test sequence with the pressures used in all tests.
7. For each of the static and cyclic pressure tests, full details of all leakages, including position, extent and timing.

(1) Where a Deemed-to-Satisfy Solution is proposed, Performance Requirements H2P1 to H2P3 are satisfied by complying with H2D2 to H2D8.

(2) Performance RequirementH2P4 must be complied with.

(3) Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A2G2(3) and A2G4(3) as applicable.

Performance RequirementH2P1 is satisfied for drainage if it is designed and constructed in accordance with —

1. AS/NZS 3500.3; or
2. provided the stormwater drainage system otherwise complies with (a), Part 3.3 of the ABCB Housing Provisions for drainage of—
   1. roofs in areas subject to 5 minute duration rainfall intensities of not more than 255 mm per hour over an annual exceedance probability of 5% (as per Table 7.4.3d of the ABCB Housing Provisions) where a drainage system is required; and
   2. sub-soil areas where excessive soil moisture problems may occur; and
   3. land adjoining and under buildings.

Performance RequirementH2P3 is satisfied for footings and slabs if they are installed in accordance with H1D4(1)(a) or (b).

(1) H2D4(2)—

1. applies to every external wall (including the junction between the wall and any window or door) of a Class 1 building; and
2. does not apply to any Class 10 building except where its construction contributes to the weatherproofing of the Class 1 building.

Performance RequirementH2P3 is satisfied for subfloor ventilation if it is in accordance with Part 6.2 of the ABCB Housing Provisions.

(2) The requirements of (1) do not apply to the removal of surface water from a storm having an annual exceedance probability of 1% for a Class 10 building where in the particular case there is no necessity for compliance.

(4) Performance RequirementH2P2 is satisfied for roof and wall cladding if it is in accordance with H1D7(2), (3), (4) or (5) as appropriate.

Performance RequirementH2P2 is satisfied for weatherproofing for glazing if it is in accordance with H1D8(1).

(1) Performance RequirementH2P2 is satisfied for the design and construction of external waterproofing for roofing systems on flat roofs, roof terraces, balconies and terraces and other similar horizontal surfaces located above internal spaces of a building provided—

1. membranes used in the external waterproofing system comply with AS 4654.1; and
2. the design and installation of the external waterproofing system is in accordance with AS 4654.2.

(2) The requirements of (1) apply to—

1. roofing systems other than those complying with H1D7(2) and (3); and
2. terraces, balconies and the like other than—
   1. a concrete slab that has a minimum step-down of 50 mm below the internal floor level; or
   2. a suspended concrete slab—
      1. where the subfloor space is not used for habitable or non-habitable purposes; and
      2. that has a minimum step-down of 50 mm below the internal floor level; or
   3. spaced decking in conjunction with framing members that are suitable for external use.