Rendering, answered.
Common rendering questions, answered straight. Can’t see yours? Phone Dino and ask.
Your rendering questions
What is rendering?
Rendering is applying one or more coats of render to a wall to give it a smooth or textured finished surface. Render can be cement-based, acrylic-based or lime-based. It goes over brick and other masonry, or over panels like Hebel, blueboard and foam using a render system made for the panel, and it adds a weather-resistant coat. Dino does acrylic render, solid (sand and cement) render, Venetian plaster and texture coating.
What types of render do you do?
Four finishes: acrylic render, solid (sand and cement) render, Venetian plaster and texture coating, over brickwork, Hebel, blueboard and foam panels. Acrylic is the finish Dino focuses on most, and he has been rendering for 10 years. Each service page explains a finish and what affects its price, and if you’re unsure which you need, pick the Not sure option on the quote form.
Does render need to be painted?
It depends on the render. Plain sand and cement render is normally painted, or given a coloured finish coat, once it has cured. Acrylic render systems end with a coloured final coat, either a through-coloured render or texture, or a coloured membrane top coat that is part of the system. Either way, that top layer wears and is renewed every several years. The cement render, acrylic render and texture coating pages cover each one.
Can new render go over old render?
Yes, if the old render is sound and firmly stuck to the wall. Render makers list previously rendered and painted masonry as a suitable base, as long as it’s clean, free of loose material and any paint is well bonded. Loose, flaking or hollow-sounding render has to come off and be made good first. If the old render is sound and just looks tired, a texture coat, one of Dino’s four finishes, is often the simpler way to refresh it.
Why does render crack?
Usually because the wall behind it moves, or because the render shrinks as it dries. Bricks and panels expand and contract with heat and cold, and South Australia is known for reactive clay soils that shrink and swell under footings as they dry out and wet up. Shrinkage cracks are more likely when the mix has too much water, and render run over movement joints, or across joins between different materials, tends to crack. Acrylic flexes a little more than cement render, but no render can bridge cracks caused by the building moving.
When should I worry about a crack in my render?
Get a crack checked if it’s wider than about 1 mm: one render maker’s maintenance guide treats those as major cracks that a building professional should assess, in case there’s a structural problem. Finer cracks are less serious but can grow, so seal them and keep an eye on them. Step-shaped cracks and bulging render need checking whatever their width. Cracks are easiest to spot when the wall is wet, so look during a wash-down.
How long does render last?
Render is a long-term finish on a sound wall; what needs renewing is the coat on top. Rockcote, for example, puts ordinary exterior paint on render at 5 to 7 years before repainting, and its thicker membrane coatings at 10 to 12 years. Dark colours and homes near the coast need attention sooner, and washing the walls down about once a year helps any finish last.
How do you clean rendered walls?
Wash them down about once a year with water, a mild household cleaner and a stiff broom or brush, hosing as you go so no film dries on. If you use a pressure washer, keep it on low pressure with a wide fan tip and don’t hold it close, as that can lift the finish. Avoid solvent-based cleaners. Mould needs a fungicidal wash, because water and soap alone won’t kill the spores, and keeping plants back from the walls helps prevent staining.
How long does render take to dry?
Render is usually dry to the touch within hours, but it takes days or weeks to cure, depending on the product and the weather. Data sheets typically allow a day or two between coats, and site-mixed sand and cement render needs about 28 days to cure before it’s painted. Cool, damp or still weather slows all of it.
Do I need council approval to render my house?
Usually not, if you’re re-rendering or recoating a house that’s already rendered. South Australia’s planning rules treat repair and maintenance that doesn’t affect the structure as not needing approval, except on local heritage places. Heritage-listed homes, and houses in a State Heritage Area or historic area, have extra rules, and rendering brick or stone that has never been rendered or painted is the kind of change those rules cover. For a first-time render, or if you’re unsure, look up your address in the South Australian Property and Planning Atlas (SAPPA) and ask your council’s planning team.
Do I need strata approval to render my unit or townhouse?
Usually, yes. Under South Australia’s Strata Titles Act, work that changes the outside look of a building in a strata scheme needs the strata corporation’s approval by special resolution, with narrow exceptions, such as some two-unit schemes. Get the approval in writing before the work is booked, and check whether the group has agreed colours or finishes. If your home is community titled rather than strata, check the scheme’s by-laws too.
My house is old. What should be checked before it’s rendered?
Check for asbestos and lead paint before anything is cut, sanded or drilled, and look for damp at the base of the walls. SafeWork SA says homes built or renovated before the mid-1980s are highly likely to contain asbestos, with eaves a common spot outside, so test suspect sheeting or treat it as asbestos and leave it alone. SA Health says paint on homes built before 1980 may contain lead and should be handled with low-dust methods. Damp needs sorting out before any render goes on, as the rendering over brick page explains.
Do you quote for builders?
Yes. Dino quotes for builders as well as home owners, for rendering over brickwork and Hebel, blueboard and foam panels, with acrylic as the finish he focuses on most. Call 0485 023 241 or send the quote form with the suburb, what the walls are made of and the finish wanted.
Do you clean up after the job?
Yes. Dino keeps the site clean while he works and makes sure it’s left clean when the job is done; he takes pride in making sure a job is completed correctly. Rendering involves mixing, wet render and sometimes scaffolding, so before work starts it’s worth agreeing which areas need covering, such as windows, paths and garden beds, and where materials can be kept.
Rendering services across Adelaide.
Got a job in mind?
Phone Dino direct, or send the form. It goes straight to him.