--- title: "How to Prepare Walls Before Painting: Step-by-Step Guide | Knowledge Center | Time Paints" description: "Wall preparation prevents many early paint failures in Saudi homes. A step-by-step guide for concrete block, plaster, and gypsum walls." keywords: "how to prepare walls before painting, wall preparation before painting, paint wall preparation Saudi Arabia, primer before painting, crack filler walls, surface preparation painting" url: "https://www.timepaints.com/en/knowledge/article/how-to-prepare-walls-before-painting" canonical: "https://www.timepaints.com/en/knowledge/article/how-to-prepare-walls-before-painting" language: "en" site_name: "Timepaints-Website" og_type: "website" --- # How to Prepare Walls Before Painting: Step-by-Step Published: 2026-05-16 Category: DIY & How-To Guides Skipped wall preparation is one of the most common causes of early paint failure in Saudi homes. This step-by-step guide covers how to properly prepare concrete block, gypsum board, and previously painted walls before applying any finish coat. Saudi Arabia's most common paint problem is not a bad product — it is preparation that never happened. In the Kingdom's construction boom, speed often comes at the expense of quality. Contractors skip the base coat to save time, and homeowners, eager to move in, rush past the vital crack-filling stage. The result is a cycle of expensive repainting that could have been avoided with a few hours of proper surface engineering. Surface preparation is the foundation of any long-lasting paint system. In our extreme climate, where exterior walls can reach 60°C and interiors fluctuate with air conditioning, the bond between the paint and the substrate is tested daily. Correct preparation adds years of service life and keeps the color depth of your chosen paint true for longer. ## Assess the Substrate Before Touching It Before opening any can, spend 10 minutes assessing the wall surface beneath the paint (the substrate). Missing a problem now means discovering it through your expensive finished paint later. ### The Adhesion Test Run your hand across the surface. A loose, powdery, or chalky texture means the old paint is failing and must be removed. Use the "fingernail test": press your nail into the paint in several places. If it dents easily or feels soft, the paint layer has lost its integrity. ### The Sound of Delamination Tap the wall systematically. A hollow, "drum-like" sound indicates a delamination pocket where the plaster render has separated from the underlying concrete block. Any hollow section must be hacked out and replastered before painting begins. ### Systematic Crack Classification Look for cracks especially around window and door frames, where thermal expansion in Saudi buildings is most severe. Hairline cracks, fine lines under 0.5mm wide, are usually cosmetic and treatable with standard filler. Structural cracks wider than 1mm that show vertical or horizontal displacement are a different matter; they require a professional assessment of the building's integrity before any cosmetic work begins. ## Step 1: Remove Failing Paint and Contaminants New paint cannot anchor to a failing foundation. Any section that peels when scratched with a putty knife must be removed. For spot removal, use a rigid putty knife or paint scraper. Sand back the edges of the remaining sound paint 5–10cm around each patch — this removes the raised ledge that would otherwise show as a visible ring under the new topcoat. In coastal cities like Jeddah or Dammam, wash the walls with a mild household degreaser to remove salt spray and humidity-born oils before proceeding. ## Step 2: Repair Cracks and Holes Properly Crack repair must happen **before** priming. Filler applied over primer adheres poorly and often cracks at the edges under thermal movement. ### Handling Hairline Cracks Apply a high-quality crack filler in thin layers. Overfill slightly because filler shrinks as it dries. In Riyadh's dry heat, drying takes 4–6 hours; in coastal humidity, allow at least 12 hours. Sand flush with 120-grit sandpaper. ### Solving Large Structural Movement For cracks wider than 1mm, standard acrylic fillers are insufficient. Use an epoxy-based crack filler like **Time Epoxy Crack Filler**. It is designed to resist the intense thermal expansion and contraction cycles of Saudi concrete block construction, ensuring the crack doesn't re-open after the first summer. ## Step 3: The Forgotten Step: Sanding and Cleaning Sanding is the most skipped step in Saudi residential projects, yet it is essential for a professional finish, especially if you plan to use a semi-gloss or silk finish. Sand the entire wall lightly with 150-grit paper. This doesn't just smooth the surface; it creates a "mechanical key" that allows the primer to grip the wall. After sanding, dust removal is critical. During sandstorm season (February–April), dust accumulates in minutes. Wipe the walls with a barely damp cloth and prime immediately once dry. ## Step 4: Apply an Alkali-Resistant Base Coat The base coat (primer) is the shield that protects your topcoat from the wall. New concrete and fresh plaster in Saudi Arabia are highly alkaline. Without an alkali-resistant base coat, the topcoat reacts chemically with the wall (a process called saponification), causing blistering and peeling within months. A quality primer like **Time Sealerin** seals the alkalinity, provides a uniform surface, and actually saves you money by reducing the amount of expensive topcoat the wall "drinks." New plaster must cure for at least 28 days before any paint is applied. Starting before that point creates a high risk of blistering as the curing plaster releases gases, and widespread adhesion failure shortly after. ## Step 5: Smoothing with Putty (The Majlis Standard) For formal spaces where surface quality is paramount, apply a thin skim coat of interior wall putty over the primed surface. This fills micro-porosity and minor irregularities, creating a "glass-smooth" surface. Apply putty with a wide steel trowel, allow to dry fully, and sand with 180-grit paper. This step is what separates a DIY-looking wall from a luxury villa finish. ## Step 6: Application of the Final Coat During Saudi summers, avoid painting exterior walls when the surface temperature exceeds 40°C. Paint in the early morning or late afternoon to prevent the paint from drying too quickly, which causes "lap marks." For the exact coat count and waiting time between coats, see the Technical Specification tab on each product below. ## Frequently Asked Questions ### Q: [](https://www.timepaints.com/en/faq/dw7kg/why-did-my-new-paint-start-peeling-after-only-six-months) ### Q: [](https://www.timepaints.com/en/faq/gxjzd/can-i-just-use-more-paint-instead-of-filling-cracks) ### Q: [](https://www.timepaints.com/en/faq/eyk1g/do-i-really-need-to-sand-the-walls) ### Q: [](https://www.timepaints.com/en/faq/dz64e/how-do-i-handle-walls-in-high-humidity-areas-like-jeddah) ## Related Products - [Time Bright Timeal Silk](https://www.timepaints.com/en/product/time-bright-timeal-silk) — A high quality shin enamel topcoat paint pure white, based on modified alkyd resin It is characterized by excellent leveling.- [Time C Primer](https://www.timepaints.com/en/product/time-c-primer) — A high quality primer with high adhesion and resistance to moisture and alkali.- [Time Crack Filler](https://www.timepaints.com/en/product/time-crack-filler) — A paste is composed of a high-strength filler, working on filling and treating cracks and holes up to 1cm.- [Time Gypsoneat](https://www.timepaints.com/en/product/time-gypsoneat) — A paste for interior gypsum surfaces, which works on leveling the surfaces to give them a soft touch devoid of any meanders.- [Time Nova](https://www.timepaints.com/en/product/time-nova) — Pure acrylic water-based paint, silky and smooth to the touch, characterized by easy removal of stains and dirt, washability with soap and water.- [Time Pure](https://www.timepaints.com/en/product/time-pure) — Finish coat on concrete, cement, gypsum, hardboard and brick surfaces for exterior and interior applications, where easy clean and excellent washability is required.- [Time Putty](https://www.timepaints.com/en/product/time-putty) — A high quality water borne putty, based on special formulation, designed for leveling and smoothing surfaces.- [Time Sealerin](https://www.timepaints.com/en/product/time-sealerin) — A water borne primer based on acrylic emulsion, which is specially designed for hot and cold climates. It is suitable for all weather conditions.- [Time Sealerx](https://www.timepaints.com/en/product/time-sealerx) — Water-based paint, designed to suit hot and cold climates and various weather conditions.- [Time Ultimate](https://www.timepaints.com/en/product/time-ultimate) — An easy-to-apply filler used to completely fill and repair small cracks and holes up to 2cm by 2cm. --- **Keywords:** how to prepare walls before painting, wall preparation before painting, paint wall preparation Saudi Arabia, primer before painting, crack filler walls, surface preparation painting --- [Knowledge Center](https://www.timepaints.com/en/knowledge) | [Home](https://www.timepaints.com/en) --- [العربية](https://www.timepaints.com/ar/knowledge/article/how-to-prepare-walls-before-painting)