Casa Castellon is a 2005 single story, 3400 sq ft home with 10 ft block walls on the North and South walls and 15 ft block walls on the East and West walls. Construction is block topped with frame. Floor trusses are laid north to south and rest upon the north and south 10’ block wall. Roof has a 2:12 pitch surrounded by 2 ft parapet walls. Current roof is TPO (2010) over Modified Bitumen (2005).
Parapet walls are raised at each corner of the house and each lack proper coping/caps. This is the main weakness in the roof’s ecosystem and the source of the four perimeter leaks inside the house. The Arco is disintegrating on its east (back) side and it is the main source of leaking in the Great Room on the Southwest side of the house.
ALL RAISED PARAPET CORNERS AND ARCO (arch over front door) MUST BE REMOVED FROM THE ROOF SYSTEM
It is at these corner areas, which were poorly designed and further, poorly executed by failing to apply proper coping/flashing, that water entered through the inevitable resulting cracks in the stucco and migrated between the TPO and Mod Bit and into the old drains (from the mod bit system) where it was directed outward via the pvc pipes of the drains toward the exterior plywood fascia.
The old drain system was abandoned in favor of scuppers and parapet outlets and yet the pvc drains were left in place in the roof. It seems the drain outlets facing the plywood fascia in the building envelope were closed. The entrance to each old drain, however, was left open. Water travelled between the two roof membranes, entered the old drains or overflowed at the mouth of the old drain. Where the water could not exit it drained down the plywood fascia.
There are only four visible leaks in the house. All located at the exterior and all associated with the old drains and the pattern described above.
2005: During construction a Modified Bitumen Roof was installed with an interior/attic drain system with drain pipes most likely directing water through the 10’ block wall and out to the street.
Please refer to the BLUEPRINT page of the site, here.
2010: Problems began, most likely as stucco cracks originating at the top of the raised parapet corners. New TPO roof installed in 2010 and roofer also constructed new drainage outlets in parapet wall as well as installed 12 scuppers (6 on north wall, 6 on south wall).
In several areas the drainage outlets were constructed too high to enable water to adequately exit resulting in ponding.
Nearly all stucco cracks are associated with the CORNER AREAS of the exterior parapet walls. Lack of coping/flashing on top of these WOOD FRAME decorative parapet corners laid the foundation for the problems we are seeing today.
PROPOSED SOLUTIONS:
ROOF:
- All raised parapet corners and Arco must be removed from the roof/wall system.
- Existing Modified Bitumen and TPO membranes must be removed down to the roof deck. Areas of plywood which have sustained water damage must be removed along with 12 drains.
- Current parapet wall flashing along with the single line of old barrel tiles will be removed. New metal flashing will be applied and topped with faux limestone architectural molding along entire top line of parapet wall.
- New iso must be properly sloped to enable water to exit through the outlets which are currently too high in several areas.
STUCCO:
- Stucco on home’s envelope will be demo’d from a few inches below the ‘patched’ midline up to the top of parapet wall.
- Water damaged plywood will be removed and replaced with Densglass.
- Then Tyvek, lathe, scratch/brown/finish in skip trowel stucco rather than smooth sand. Current stucco is skip trowel.
Please note: ALL exterior plywood fascia comprising the sheathing envelope of the house above the block portion of the North and South walls should be replaced with Densglass. In effect, creating an envelope comprised of cementitious materials for maximum water/moisture resistance.
PLEASE REFER TO BLUEPRINT PAGE FOR FURTHER REFERENCE
2023: New TPO roof overlay installed over Modified Bitumen roof which was overlaid with original ISO board. MOD BIT roof in pristine condition. Left as is. Old drains removed. New Scuppers installed. New crickets and sloping installed. Replaced damaged ISO boards which were limited to the NORTH and SOUTH side perimeter edge areas. ALL ISO board on the rest of the roof was pristine and did not need replacement. Original stucco above concrete block wall (10’) removed, damaged plywood removed and replaced and new stucco applied. House repainted with Sherwin Williams Duration Kilim Beige and Tricorn Black.