Preventing Water Damage: Capillarity, Filtration, Condensation

Posted on Jan 19, 2025 in Geology

Capillarity: Basic Techniques to Prevent Water Damage

Filtration

Phases:

  1. Wetting and saturation (the larger, the slower the rate of suction). Slow and fast.
  2. Sheet as texture and superficial “adsorption”.

Penetration Routes:

  1. Porous structure
  2. Construction seals (flat, angled)
  3. Expansion joints
  4. Joint practices
  5. Breaks (cracks, fissures)

Water Tightness:

  • Exposure level
  • Façade geometry (angles and corners)
  • Physical properties of materials (suction and absorption)

Drainage:

Depends on:

  1. Tilt of horizontal planes.
  2. Flaps on each vertical and horizontal plane.
  3. Existence of a drip edge in flanges.

Hot Spots:

  1. Blind spots
  2. Front boot
  3. Window openings
  4. Moldings and cornices
  5. Terraces and balconies

Causes:

1. Blind Spots:

  • Wounds without mortar or recessed in brick façades
  • Excessive suction of the exposed material or mortar
  • Cracks when they appear (no expansion joints themselves)
  • Inadequate plastering or rendering, with high suction
  • Cracks and fissures, where they appear.

2. Expansion Joints:

  • Lack of the enclosure’s own seal
  • Execution error
  • Slightly deformable sealant.

3. Front:

  • Capillary dampness
  • Dampness from the ground due to “microcapillaries”
  • Seepage from the sidewalk
  • Splash of rain from the sidewalk

Prevention Measures in Construction Design:

  • Avoid the use of mortars and paints on the curb
  • Incorporate a socket, if possible, depending on detail, with:
    • Waterproof membrane on the exterior of the socket
    • Overlap the front finish on top
    • Overlap vertical cloth finishing on pavement with a sealed joint
  • Set material resistant to abrasion and water ratio less than 3% absorption and suction less than 0.15 g / (cm2.min) pavement, sealing).

4. Terraces and Balconies:

  • Filtration downstairs, due to lack of waterproofing, or cracking of the pavement
  • “Microcapillaries” in front and parapet (similar to the socket)
  • Filtration on the premises through the balcony door, due to lack of overlaps and sealing
  • Filtration breastplate system at work due to poor drainage (small gargoyles).

5. Window Openings:

  • Gutter filtration due to:
    • Little inclination, porous material, lack of a drip edge
  • Lack of overlap and sealed joint in the meeting with carpentry and jamb flashing
  • Practicable boards, with the possibility of water passing by:
    • Sliding
    • Inadequate drainage holes in the decompression chamber
    • Lack of a drip edge on the lower horizontal board with inverted overlapping
    • Unsealed miter decompression chambers

6. Moldings and Cornices:

  • Permeable material on the upper surface of the molding or coping
  • Superior vertical capillary cloth material
  • Unsealed horizontal dihedral board
  • Cracks caused by shrinkage
  • Lack of a drip edge at the edges

Condensation

Hot Spots:

  • Interior surface condensation on a cloth that is little isolated or poorly ventilated (Single Sheet)
  • Front-closet adjoining interior surface condensation
  • Coronations and corners with little ventilation and internal openings of windows
  • Thermal bridges of encounter with the structure
  • Interstitial condensation in meetings with the structure

Repair:

  • Exterior insulation
  • Vapor barrier
  • Interior window openings (plastering with mortar on the inner opening and a cement chute to collect condensation)

Accidental Causes

  • Mechanical problems (surges, mechanical action)
  • Chemical problems