How to Render a Wall
Prepare the wall for rendering., Mix the render., Apply the scratch coat of render to the wall., Scratch the first coat of render to prepare it for a second coat., Apply the second coat of render to the wall.
Step-by-Step Guide
-
Step 1: Prepare the wall for rendering.
If the wall has previously been rendered and the plaster is deteriorating, start by sawing or raking as much of the old plaster away as possible.
Once the old render is removed, wet the wall using a garden hose.
Apply more water to walls made from very porous materials. -
Step 2: Mix the render.
Renders are a mixture of only 3 ingredients: lime, sand, and water.
Portland cement can be substituted for a portion of the lime, which will result in a stronger, but less breathable plaster.
Use either hydrated lime or lime putty, and mix 1 part lime to 3 parts sand in a large bucket or wheelbarrow.
You must use sand with sharp, angular grains; masonry sand is the ideal choice.
Add just enough water to form the mixture into a stiff, workable paste. , Render is most effective when it is applied in several layers, and the first layer is called the scratch coat.
Apply the render to the wall as forcefully as possible to ensure that it keys into the wall well; throwing clumps of render from a trowel or from your hands in the best method.
Smooth the render across the wall with a trowel.
Never make repeated passes with the trowel over the same area; this will bring the lime to the surface and leave you with a weak, lime-depleted section underneath. , Once the first coat of render is applied but not yet set, scratch the surface throughout the wall to provide a key for the next layer to adhere to.
These scratches can be applied using a hand cultivator or the edges of a trowel. , Once the first coat has been scratched and allowed to set most of the way, wet the wall again with the hose.
Apply the second coat of render in the same manner as the first.
If a third coat is desired, scratch the surface of the current coat to provide a key.
If not, let the render dry slowly, and you are done rendering the wall. -
Step 3: Apply the scratch coat of render to the wall.
-
Step 4: Scratch the first coat of render to prepare it for a second coat.
-
Step 5: Apply the second coat of render to the wall.
Detailed Guide
If the wall has previously been rendered and the plaster is deteriorating, start by sawing or raking as much of the old plaster away as possible.
Once the old render is removed, wet the wall using a garden hose.
Apply more water to walls made from very porous materials.
Renders are a mixture of only 3 ingredients: lime, sand, and water.
Portland cement can be substituted for a portion of the lime, which will result in a stronger, but less breathable plaster.
Use either hydrated lime or lime putty, and mix 1 part lime to 3 parts sand in a large bucket or wheelbarrow.
You must use sand with sharp, angular grains; masonry sand is the ideal choice.
Add just enough water to form the mixture into a stiff, workable paste. , Render is most effective when it is applied in several layers, and the first layer is called the scratch coat.
Apply the render to the wall as forcefully as possible to ensure that it keys into the wall well; throwing clumps of render from a trowel or from your hands in the best method.
Smooth the render across the wall with a trowel.
Never make repeated passes with the trowel over the same area; this will bring the lime to the surface and leave you with a weak, lime-depleted section underneath. , Once the first coat of render is applied but not yet set, scratch the surface throughout the wall to provide a key for the next layer to adhere to.
These scratches can be applied using a hand cultivator or the edges of a trowel. , Once the first coat has been scratched and allowed to set most of the way, wet the wall again with the hose.
Apply the second coat of render in the same manner as the first.
If a third coat is desired, scratch the surface of the current coat to provide a key.
If not, let the render dry slowly, and you are done rendering the wall.
About the Author
Heather Patel
Committed to making practical skills accessible and understandable for everyone.
Rate This Guide
How helpful was this guide? Click to rate: