CASE STUDY


Aamsko, in partnership with Zenith Facilities Services, was commissioned to assess and provide remedial solutions for the weathertightness failures concerning three buildings in Newmarket, to provide the client with invaluable insight into the health and longevity of these three buildings, to allow an informed strategic plan for the finding, investment and renovation renovations.

The buildings have a unique building envelope design utilising precast and in-situ concrete, concrete masonry blocks together with glazed aluminum curtain wall systems.

Zenith Facilities Services conducted forensic water and moisture ingress documentation under the guidelines of ASTM E 2128 to obtain a forensic understanding of the building’s condition so that a suitable remedial maintenance scope and specifications can be attained.

The data was gathered via internal and external visual inspections, together with moderately invasive internal inspections and water ingress testing, involving the roof, walls and joinery to identify vulnerabilities and point of failure for all three buildings. The results highlighted several weathertightness concerns of similar nature contributing to the water and moisture ingress presenting at the buildings.

Based on our inspections and information available from the property file, Aamsko created detailed drawings to clearly depict the weathertightness failures and points of water/moisture ingress into the buildings.

Concrete Cantilever Balconies with Concrete Masonry Parapet

The balconies are flooding due to lack of correct fall and drainage, resulting in water entering the building due to the lack of an adequate upstand for the sliding door. Water seepage from the cold join of the balcony deck and the parapet wall due to the decks flood can be visually observed. Due to prolonged and consistent moist condition of the masonry block parapet and lack of flashings, cracks are presenting because of over carbonation, and the steel balustrade rail is rusted beyond safe use. Insipient anode syndrome has begun to present where concrete has commenced to spall around the mounting of rusted parapet rails.

Internal Gutter System – Ingress at Concrete Masonry Wall and Glazed Curtain Wall

The internal gutters of the buildings are constructed of plywood substrate, with metal box guttering and waterproof membrane that has exceeded its useful serviceable life. AAMA 511 water ingress testing of the internal gutter systems resulted in water and moisture ingress into the internal space at several locations in the three buildings is a result of the internal gutter system, due to the lack of gutter capacity, fall, and poor design/workmanship. The internal gutter was determined to be the cause of ingress through AAMA 511 water ingress testing and the monitoring of moisture levels as the tests were conducted at the masonry black walls.

The inadequate fall of the internal gutter system is causing to water pooling for long periods of time. This results to premature degradation of waterproofing and the timber substrate, leading to overflow into interior of the building and a prolonger moisture seepage into concrete black walls.

Protruding Fin Detail

The façade design of two of the buildings has radial protruding concrete masonry fin detail, the defects of which observed to be worse at Level 2 and the site of the central fin below the internal gutter end.

Significant moisture ingress damage in the form of efflorescence and loss of adhesion to paint where the fin protrudes the interior space. This moisture damage continued to the exterior of the fin, tracking along the masonry block joints. Water-marked timber framing and plywood was present around the internal gutter, with a gap in the gutter visible from the interior. On the roof, the flashing wrapping the concrete masonry fin has wet marks, with water retained under the cap flashings at fixing points.

AAMA 511 water ingress testing was conducted at the internal gutter, and water ingress was observed, with the amount of water increasing as the gutter exceeded its capacity and overflowed. Water leaked through a gap in the gutter system, splashing down onto the loadbearing pillar before spilling onto the floor. Water ingress into the internal space is due to lack of gutter capacity, fall, and poor design/workmanship.

Internal Intertenancy Party Wall

The reinforced concrete masonry intertenancy wall on the ground floor at one of the buildings shows signs of moisture ingress and damp rising on both sides of the wall. The defects presented as loss of paint cohesion, concentrated at the base of the wall, suggesting it originates from the ground or carpark below. The carpark concrete masonry retaining wall directly below has severe muddy water marks and mould growth.