Insulation & Water Proofing
- Precast concrete slabs.
- Casting concrete surfaces in place.
First: Insulating ready-made concrete surfaces:
- Insulating hollow slabs:
- Filling longitudinal joints:
- A 10 mm diameter iron rod is stretched along the entire longitudinal gap with spacers not less than 2.5 cm to ensure a sufficient covering layer of iron from below, with emphasis on the overlap distance at iron connection points not less than 50 cm.
- The iron rod stops before the expansion joint at the perpendicular transverse joints, which is necessary for implementing the expansion joint.
- The joint is filled with a cement mortar consisting of sand, water, and cement weighing 250 kg/m3.
- The joint surface must be prepared and well-aligned to be at the same level as the hollow slab surface on all sides.
- If there are differences in elevations between adjacent slabs exceeding 2 cm, these differences must be removed by pouring slight inclinations to fill the gap.
Pouring cross joints:
Exposed joints refer to the distance between the support points of the hollow slab on its delta, with a width of about 20 cm and the thickness of the hollow slab, along its delta.
- Iron bars with a diameter of 10 mm are extended to be fixed on the protruding support from the soffit surface, ensuring an overlap of no less than 50 cm at connection points.
- Foam panels with a thickness of 2 cm are installed to the height of the hollow slab along the entire length of the expansion joint and secured in place.
- The cross joint is poured with a concrete mix with a strength of 350 kg/cm2.
- Proper finishing and leveling of the poured surface.
- In case of poorly finished areas containing protrusions or high spots that may compromise the insulation later on, these areas are sanded down.
Insulating longitudinal joints:
- The joint is primed with bituminous material to enhance adhesion between the membrane and the concrete surface, by coating a strip approximately 30 cm wide.
- A strip of bituminous membrane coils with a thickness of 3 mm and a width of 25 cm is applied, ensuring a vertical overlap of about 15 cm.
- Sectional insulation:
The joint is primed with a material approximately 60 cm wide. A strip of bituminous membrane rolls with a thickness of 3 mm and a width of 50 cm is applied with a vertical overlap of about 15 cm.
Expansion joints:
Expansion joints existing in some cross joints are treated as follows: foam strips with a thickness of 2 cm, equal to the depth of the hollocore, are placed, then these expansion joints are poured as follows: as previously explained.
Treatment of expansion joints is as follows:
- The joint is cleaned along its entire length and to a depth of approximately 4 cm.
- Filling foam with a diameter of 3 cm and inserting it into the clean space, leaving a gap of about 1 cm between the top of the filling foam and the hollocore surface.
- Filling the remaining gap above the filling foam with bitumen filler to completely fill this gap.
- Another foam filler with a thickness of 3 cm is placed above the filler and along the length of the joint to form a flexible thickness over which the membrane extends, allowing for additional length to be added to the membrane during contraction under low-temperature conditions.
- A layer of 3 mm thick membrane with a width of 50 cm is carefully adhered above the joint without distorting the filling rod. Another strip of insulation layer is attached as a final layer. Insulating Gregory drainage beams:
- The beams of the mezzanine are primed with a layer of bitumen.
- Special coating is applied to the drainage openings of the membrane.
- The first layer of membrane with a thickness of 3 mm is adhered.
- A second (final) layer of membrane with a thickness of 3 mm – polished – is applied, finished with a layer of sand.
- The second layer is painted with acrylic material for external surfaces, white in color, to protect the insulation from sunlight.
