Punjab PSEB Sr. Sec. NSQF Construction (Painter & Decorator) common mistakes
Punjab PSEB Sr. Sec. NSQF Construction (Painter & Decorator) · Understand the traps and how to avoid them.
Cleaning brushes and rollers in the nearest sink or drain, and leaving thinner-soaked rags in an open heap at the end of the shift, then reporting the site as 'cleaned up'.
It happens at the end of a long shift when the only water point is a washbasin, and nobody has placed a labelled waste container on site, so the fastest option wins. Candidates also assume small quantities of thinner are harmless.
What to do instead
Before starting, set a three-point waste station: a labelled solvent-waste drum with lid, a metal rag can with self-closing lid, and a settled wash bucket for the three-bucket brush-cleaning routine. Never pour washings into drains or soil; hand over to the authorised waste collector and record the quantity.
Standing on the top two rungs of a ladder, over-reaching sideways to cut in a ceiling line, and leaning the ladder at a shallow angle with the top resting on an unsecured surface.
Most patch-and-cut-in jobs look too small to justify a mobile scaffold, so the ladder becomes a work platform and the body stretches instead of the ladder being moved.
What to do instead
Set the ladder at roughly 75 degrees (1 unit out for every 4 units up), extend it about 1 m above the landing point, tie or foot it, and keep three points of contact. Move the ladder for every reach rather than stretching. For any task needing both hands or more than a short reach, use a guarded mobile scaffold instead.
Applying putty and the first coat to freshly plastered walls as soon as they look pale and dry to the eye, without measuring moisture, then blaming the paint when alkali burn, blistering or patchy sheen appears.
Programme pressure pushes painting forward, and dry-looking plaster is mistaken for cured plaster. New plaster can look dry while still holding enough moisture to destroy adhesion.
What to do instead
Allow new plaster to cure (commonly several weeks, longer for thick render), and confirm with a moisture meter before coating. Treat alkaline or highly porous plaster with the specified alkali-resistant primer and check the pH/ moisture condition again before the finish coats.
Putting the finish enamel straight onto bare steel or onto a fresh putty patch, or using a water-based wall primer on metal, simply because that tin was open.
Primers all look like 'white paint', and candidates memorise product names rather than the substrate-to-primer matching rule, so the nearest tin gets used.
What to do instead
Match primer to substrate and to the topcoat system: zinc-rich or red-oxide type primer for ferrous metal, alkali-resistant primer for fresh plaster, and a suitable primer/sealer over putty before emulsion. Check the product data sheet for the correct primer when the system is not already specified, and never rely on the topcoat to compensate for a missing primer.
Adding extra thinner 'to make it flow' and then laying one heavy coat to cover the wall in a single pass, producing sags, runs, wrinkling or a film that never hardens properly.
Thinning makes brushing easier and one thick coat looks faster than two thin ones, so the shortcut feels like skill. The datasheet thinning ratio and wet-film thickness are rarely checked on site.
What to do instead
Thin only within the manufacturer's stated ratio and measure it, do not judge by eye. Apply two thinner coats rather than one heavy coat, check wet-film thickness with a gauge where a dry-film specification exists, and keep brush/roller passes in one direction per coat to control film build.
Recoating as soon as the surface feels touch-dry, so the second coat traps solvent and the film later blisters, lifts or shows brush drag and roller marks.
Touch-dry is confused with recoat-ready, and the recoat window printed on the tin is ignored under time pressure. Humidity and cold weather extend the real interval without changing the label.
What to do instead
Follow the recoat interval on the product data sheet and adjust for temperature and humidity; record the time of each coat on a simple site card. Where the maximum recoat window has been overrun, abrade the surface before recoating so the next coat can key.
Starting a texture, stencil or faux-finish straight onto a glossy, dusty or patched wall, working on the client's wall as the first test, and stopping partway when the pattern looks wrong.
Decorative work feels like an artistic step rather than a surface-preparation step, and the cost of a test panel is seen as wasted material.
What to do instead
Prepare and prime the base to a uniform sheen and absorbency, then produce a small test panel on site and get the client's approval of colour, pattern and sheen before starting. Mark out and protect adjacent surfaces, work in complete sections to a natural break line, and keep the same batch and tool set throughout.
Estimating paint and putty by 'one litre per room' or by counting rooms, and measuring the wall as length times height without deducting doors and windows.
Room-based rules of thumb are remembered from casual work and are never checked against the coverage rate printed on the tin, which is stated in square metres per litre per coat.
What to do instead
Use the measurable method: wall area = perimeter x height minus openings (with the frame deduction rule applied consistently), then divide by the coverage rate from the data sheet, multiply by the number of coats, and add a stated wastage allowance. Show the calculation line by line in the quotation so the client can check it.
Accepting a job on a verbal understanding, with no written scope of areas, number of coats, brand or sheen of paint, rate, payment stages and completion date, then arguing about extras at handover.
Small domestic jobs are treated as informal favours, and writing a quotation feels like distrust of the client. Candidates also lack a standard template, so they improvise or skip it.
What to do instead
Use a one-page written quotation/work order for every job: measured areas, preparation and number of coats, product and sheen, rate and total, advance and stage payments, start/finish dates, and what is excluded. Get it signed before work starts and record any variation in writing, including the drying/curing time the client must allow.
Rectifying a defect by sanding the spot, brushing on fresh paint and leaving a hard edge, so after drying the repair 'flashes' - visible as a patch with a different sheen or a halo under raking light.
The visible symptom is treated rather than the cause, and the repair is judged while still wet, when it blends into the surrounding film. Hard edges and unprimed patches only show up after the film has dried and the light falls across it.
What to do instead
Identify and remove the cause first (moisture, poor adhesion, incompatible coat), cut back to sound coating, feather the edge, prime the bare patch to match absorbency, then recoat to a natural break line such as a corner or whole wall. Inspect dry film under raking light before signing off to the client.