Plastering Contractor in Jeddah

Choosing the plaster for the wall and its exposure

Plaster is not one product. The right system depends on the substrate behind it, whether the wall is inside or outside, and what will be applied on top. Specify it surface by surface, and follow the manufacturer's data sheet and the consultant's specification for mix, thickness and curing.

What Jeddah and Riyadh do to fresh plaster

In hot, dry conditions the surface can lose water faster than the cement can use it, leaving weak, dusty plaster and fine map cracking. That is why curing matters as much as application. Riyadh adds wind-blown dust and wide day-to-night swings, which put thermal movement into the wall. In Jeddah, humid, salt-laden air brings a different risk: salts in sand or mixing water surface later as white staining, and they corrode ordinary steel beads and mesh.

• Dampen absorbent block or concrete first, so the wall does not draw water out of the coat.
• Shade external work from direct sun and drying wind, and cure it the way the data sheet directs.
• Use clean, low-salt sand and mixing water, especially near the coast, and galvanized or otherwise protected beads and mesh.
• Lay mesh across junctions between different substrates and over chases, and carry building movement joints through the plaster with a proper profile instead of bridging them.

Defects and what actually causes them

• Map cracking: a mix that is too rich or too wet, rapid drying, or no curing.
• Hollow patches that sound drummy when tapped: dust or laitance left on the surface, smooth concrete that was not keyed, or dry block that was not dampened.
• Cracks along block and concrete junctions or above chases: movement between materials, with no mesh to hold the join.
• White staining (efflorescence): salts in the materials, or water moving through the wall from a leak or missing waterproofing.
• Walls out of plane and corners out of square: no screed rails or beads set out first, so every later trade inherits the error.
• Paint blistering or peeling later: plaster painted while still damp, alkaline or dusty.

Checks before the next trade starts

1. Approve a sample panel of the agreed system and finish before the full run starts.
2. Tap-test every wall for hollow areas; a hollow patch under tile or paint will fail later.
3. Check flatness with a straight edge, and plumb and level at corners and openings, against the tolerance in the specification rather than by eye.
4. Confirm that chases and embedded services were tested and closed before plastering.
5. Rub the surface by hand; it should not dust or powder.
6. Keep a record of curing, and hold the next trade until the surface suits its system.

What to write into the scope and BOQ

• Internal and external plaster as separate items, each naming the system.
• Beads, mesh, control joints and stop ends included, not left as later extras.
• The flatness tolerance, and how and when it will be checked.
• Curing method, and who is responsible for it.
• Scaffolding or access for external work, and who makes good after later chasing by the electrical and plumbing trades.

A full elevation, such as the render applied from scaffolding at the commercial and office building in Riyadh, is where these controls matter more, because a facade shows every change in mix, joint and drying. For wider questions to put to any contractor, see Questions to Ask Before Hiring a Finishing Contractor in KSA.