Roof Repairs to High Rise Apartment Block               
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Cut out and remove 3 areas , allow to dry out or force dry with flame torch.
Weld cut edges directly to the original mastic asphalt underneath.
Burn and scrape off the aluminium paint from each area for bonding new membrane to old mastic asphalt.
Torchdown new membrane with side laps to match existing membrane and  150mm overlap onto existing good membrane.
Heat and trowel all lap edges.
Cut out the perimeter metal flashings from the wall and remove from site, rake out a new chase.
Cut the perimeter upstands at the base, remove from the mastic asphalt substrate.
Warm and scrape off the aluminium paint around the perimeter 150mm wide for bonding the new membrane to old.
Reinstate new torchdown membrane upstands full height to the bottom of the new chase and 150mm out onto the existing flat membrane.
Install new Zincalume flashing same shape as before to the new chase and plaster up with Renderoc Modified Plaster.
Coat new plaster with 2 coats of white acrylic paint.
Dispose of all torn off materials.
area where water has penetrated under the torchdown membrane and is trapped close up of same area, loose counterflashing the cause of the water penetration
a. metal counter flashing b. top of torchdown membrane flashing loose c. original mastic asphalt upstand another area with water trapped between the two membranes
the area in first pic cut open and peeled back for repair close up of the torchdown flashing removed from wall, not enough flame applied to bond to mastic asphalt upstand
sealing the cut edge of the main torchdown area which is still good another area removed, sealing the edge of the good membrane
two areas torn open for repair burning and scraping off the aluminium paint surface of the original mastic asphalt to ensure a good bond with the new torchdown repair
aluminium paint removed ready for repair applying the new torchdown membrane
1st area repair completed, ready for aluminium paint UV coating 2nd area repaired
3rd area, water trapped between the 2 roof membranes, pooh what a stink the same area repaired
a view of the 3 areas repaired, stage 1 completed view of Wellington from the roof top
view of apartment building from the hills above closer view the roof top