Falling exterior wall cladding – causes, countermeasures, repair methods

Falling exterior wall cladding – causes, countermeasures, repair methods

Coated buildings: ceramic mosaic/ceramic tiles/glass mosaic/natural stone/artificial stone/marble – when these fall, they pose an immediate danger to life, and the building becomes a dangerous structure requiring immediate renovation.

Background: the cladding is usually made with ceramic/stone/glass materials that meet the relevant Israeli standards (ceramics – standard 314 and ceramic/glass mosaics standard 1353), the tiles are extremely rigid and have a high specific gravity. Therefore, the total weight of the building’s cladding is cumulatively high Very much. The great weight of the covering naturally pulls the covering downwards, therefore a strengthening and anchoring system and quality gluing is required. Standard adhesives in accordance with the requirements of MPC 431 for the type of glue and MPC 362 for the glue mixture.

Falling Exterior Wall Cladding www.denber.net

Falling Exterior Wall Cladding www.denber.net

Falling Exterior Wall Cladding www.denber.net

Reasons for adhesion failure – the causes of detachment and fall of hard exterior cladding

  • A. A poor quality glue with low adhesion which weakens completely in contact with rainwater and completely loses its original adhesive power.
  • B. High-quality glue that has absorbed large amounts of water from poor leak/spill sealing and that has weakened significantly.
  • third. An adhesive without flexibility that does not hold the tile in light shocks/vibrations, earthquakes, building subsidence, etc.
  • d. Weak plaster with a little cement that is applied to a dry wall without proper wetting (which does not withstand the load of the cladding and falls with it).
  • God. The gluing done on the non-planar plaster/plaster layer, which had to insert a mesh and perform alignment, too thick alignment (over 3 cm) of such a surface without a steel mesh will cause the alignment layer to fall off with the cladding.
  • and. Bad adhesion by the gluer, the adhesion area is too small. Too little glue applied. The weight of the coating overcomes the adhesion force per square meter and the tile detaches.
  • G. The cladding work began before the plastering of the cement finished – 28 days.
  • H. No expansion joints were made in the outer walls of the building in concrete or expansion joints and separation joints of at least 6 mm in the structure, at least every 3-5 m that pass between the vertical and horizontal cladding tiles and the cracking of the structure due to undirected displacement creates a sliding of the cladding according to the cracking and falling out.

Falling of exterior cladding from the walls of the building

  • ninth. Adhesion to cast concrete elements without removing mold oil and/or dirt/dust which prevent adhesion to the entire surface in the first place but only to parts of it.
  • J. The cladding was carried out on an uneven wall where the height difference along a 2 m ruler exceeds 1.5 cm.
  • 11 Improper use of additives in the plaster and adhesive layers.
  • 12. Exterior plaster made with dirty quarry sand or with lime is not suitable for exterior coating and will crumble.
  • 13. A structure made of aerated concrete blocks on which a suitable grid was not installed (galvanized / FLAVM)
  • Hand. Mesh mesh was not properly reinforced at least every 30 cm into the block.
  • Tu. Gaps of less than 4 mm were left between the covering tiles (with the exception of mosaics), which prevented a strong and full sealing of the gaps. And allowed water to penetrate behind the tile and contact the adhesives. Without a sealed quarter/reinforcement, the cement and acrylics weaken from the water until they disintegrate and the covering falls off
  • 16 Covering that has been glued on structural farms (expansion farms, intermediate farms, separation farms) falls off in the first year of inspection or later, but that’s when the shedding will begin.
  • 17 A poor quality gun that allowed rainwater to penetrate and thus the cumulative deterioration of the plaster and adhesives.

Falling of exterior cladding from the walls of the building

Analysis of the situation in the field, identification of the reasons for the failure – repair specification 

Identification of the cause/reasons for the falling of the covering according to sections A – VII which are the cause of the falling of the covering.

Strategic execution specification according to the reason for the cladding attachment failure.

.1. Detection of expansion seams, interstitials and separation –  elastomeric repair and filling as needed with Polyflex Sausage putty injected for a thin seam and with a backing profile for a large seam. Or better, Polyflex 225 two-component high strength durable for many years.

2. Exposing loose cladding by clicking and removing it. Scratching and scraping old glue.

3. Plaster repairs if required. Adding reinforcement mesh if the area is large (anchor the mesh every 30 cm at least, type of mesh: steel, in a chemical or salty/marine atmosphere – stainless steel mesh.) New plaster up to a suitable level while leaving a gap for gluing. The gluing must be done at least 28 days from Applying the plaster Small areas should not be plastered and wait a month for gluing – you can level with epoxy grout and after 24 hours with Polyplex 225  glue – a flexible polyurethane glue.

4. Regluing the tiles while leaving gaps of at least 4 mm even if it is necessary to cut the cladding. Cladding without wide gaps must be scored to 4 mm even if it does not fall gently. Ceramic/glass mosaic to be pasted while maintaining a sequence of gaps, but if pasted on expansion seams or on intermediate joints and separation, change position and stick on the sides of the joints/seams (everything according to the instructions of the engineer in the field). It is necessary to use high-quality adhesives such as adhesive for individual marble tiles that have fallen off (for gluing the reinforcement of the perimeter of the tile) for flexible epoxy adhesives for small gluing intervals and / or for high-quality ceramic glue for tiles and mosaics, all according to the situation and possibilities in the field and according to the engineer’s recommendation. The most recommended and the best and most flexible to always stick with Polyplex 225 glue that  turns a strong polyurethane rubber like no other sticks and seals and is not affected by contact with rainwater.

Falling of exterior cladding from the walls of the building

5. Tying large tiles to the grid and pouring/injecting the glue into the gap. Top row if there is no clearance sharpen a suitable kent to allow injection and close the kent with a quarter.

6. Reinforcement of large marble tiles with knocking pins according to the instructions of the inspector/engineer in the field at distances of at least every 30 cm (for large tiles and less for small tiles) to a lower cladding row above which the rest of the tiles will be glued. In the future, screw reinforcements according to the instructions of the engineer in the field to prevent collapse. Accurate drilling specifications must be presented to the work manager. The screw holes in the marble will be sealed with a marble glue that matches the shade or with corks.

7. Filling voids with polyflex polyurethane mastic or high-quality quarter if the areas are large.

8. Spray  siloxane 290  on the entire surface for a perfect transparent seal and prevention of rainwater penetration. The siloxane even beautifies the appearance of the coating. The spraying must be done on all the repair areas as well as at least 2 meters from the sides of the repair areas and above them up to the roof and make sure that there is no penetration from the coping on the roof to behind the cladding. Unsealed coping is one of the causes of water infiltration into the plaster and adhesives behind the covering. It is mandatory to seal all the upper parts above the repair.

9. Of course, it is recommended to spray the entire wall and not just the repair, because if the coating has started to fall off, it can continue on all areas of the wall and not just in the area that is visible due to the coating falling off. When shedding begins, this is a warning signal, sealing and strengthening must be taken care of immediately to prevent further deterioration and shedding of cladding that can even cause injury to the soul.

10. It is also possible to seal the building from the outside once and for all with a two-component transparent polyurethane sealer Danbergloss  that is strong like no other, an excellent sealer, wear-resistant, UV-resistant.

Note: The types of adhesives and screws will be determined by the engineer in the field in accordance with the consultation and execution specification that can be consulted

To Dr. Belen Yevgenia 549 050-3551 or 050-3551551 Baruch Kogan