Brick Surface Guide
Limewash Paint on Render: The Complete Preparation & Application Guide
Render is a type of plaster or coating applied to interior or exterior walls to create a smooth or textured finish, usually rougher than traditional plaster. It’s ideal for limewashing because its porous surface absorbs the limewash effectively, allowing breathability and preserving the wall’s natural qualities. No undercoat or top coat sealer is required, making the process quick and simple.
This is the right guide for you if you want to learn how to:
- limewash internal render walls
- limewash external render walls
- prepare your surface before limewashing
- apply limewash paint
Supply Checklist
- Whisk or Electric Mixer
- Bucket
- Limewash Brush
- Limewash Paint
Lime Wash BrushesLime Wash Brushes
Limewash Paint
Whisk Mixing Tool
Planning + Preparation
During construction or renovation, it is advisable to schedule Bauwerk painting as the final trade to prevent damage to the final finish caused by other trades or building equipment.
To test your colour (which we recommend), apply it to a mock-up board with the same material or a discreet area that will be covered by furniture. Sampling directly on the surface may leave a visible patch. To minimise this leave the edges of the test patch feathered out and in a irregular shape.
The coverage of Limewash Paint on raw render is 7-10 m² per litre (75-107 ft²), per coat, with 2-3 coats required for full coverage.
Note: Recommendations for coverage are to be used as a guide only, variation in the quantity needed will depend on the porosity of the surface to be painted. We always recommend the use of sample pots for an accurate colour representation and consumption for your particular surface and light conditions.
Surface + Paint Preparation
Surface Preparation
Render surfaces should be free from any dirt, dust and loose material.
- Brush down the wall.
- Dampen walls with clean water using a brush or a light mist spray to ensure easy application of limewash paint.
Note: Previously painted internal and external render surfaces can be limewashed, but some extra preparation steps are required to ensure effective limewash absorption.
Paint Preparation
- Thoroughly stir limewash paint and decant into a suitable container or bucket. Ensure no pigment remains in the original container.
- Continue to stir the paint regularly throughout the painting process.
- Select the right limewash paintbrush: Our all-rounder brush, the 4×14 limewash brush, is great for all walls.
Limewash Paint Application
Apply 2 coats of Bauwerk Limewash Paint
- Dip your Bauwerk natural bristle brush into the paint. Remove excess paint with a flick of the wrist. The brush can hold a lot of paint, but should not be dripping.
- Start in a corner of the wall–holding the brush at a right angle to the wall. It may be best to hold the brush on the brush body, rather than the handle for more control.
- Using loose, free strokes stretch the paint as far as possible, varying the direction of strokes constantly. Let the bristles do the work. There is no need to apply too much pressure.
- Brush out the paint evenly in a thin coat, preventing runs or drips, while covering every part of the surface in the first coat. Maintain a wet edge at all times to prevent lines in your finished surface*. Finish each coat in one continuous application. Do not try and patch walls once the coat is finished, as missed areas can be covered in the next coat. With large expanses, it helps to work to a natural break in the wall, such as mortar joints.
- When wet, the colour will appear darker and transparent. Do not compensate for this by applying more paint. As the paint dries, the colour will lighten to the chosen colour and become more opaque.
- Allow a minimum of 1-2 hours between coats. Apply a second coat (no need to dampen again). Paint the second coat faster, wet-in-wet and a lot looser. Missing spots is okay, as the first coat should have covered everything. Allow the paint to dry.
If you’re painting with our ‘whites’, maintaining a wet edge is not required. These colours patch easily and are great for spot touchups.
Cleanup + Maintenance
- There is no need for a sealer or additional top coat over the limewash. A third coat of limewash can be applied, based on your colour and coverage preferences.
- All brushes, tools, and containers wash out quickly with minimal water and without harm to groundwater.
- Following these steps ensures a natural, dust-free surface with a fantastic texture, making it easy to repaint and maintain.
How to Limewash a Render Masonry Wall
Easy steps to guide you through how to apply limewash paint to naturally absorbent walls like render
Render + Limewash FAQs
How do I sample limewash paint on a raw, unpainted, render wall?
We recommend testing your limewash paint colour(s) before application. When sampling on natural, unpainted, breathable surfaces like render, apply the colour to a separate board of the same material or a discreet area that will be covered by furniture. Applying a sample directly to the surface may leave a visible patch in the finished limewash.
Can Thin Coat Render Be Used as a Finish for Internal Surfaces?
If you have a rough surface, a repaired render or a rendered finish you are not satisfied with you can consider to apply a thin coat render with a smaller aggregate size of no more than 0.6 to 1mm on top of the existing render.
Thin coat render is a pre-blended cementitious render with the addition of additives to increase adhesion and improved workability. This will be faster, more economical and a better looking surface than any other method.
For the selection of the right type of thin coat render that may be available in your particular area you should be able to tick all of the following boxes:
☑ is factory blended with additives to aid adhesion and workability and comes ready to use in a bag
☑ is cement based and need only the addition of water for mixing it
☑ is of the right grain size (for internal application we would select between 0.6mm and 2mm maximum
☑ is not water repellant (lime wash paint needs to be able to penetrate it)
☑ is of a neutral colour or grey (not pre-coloured)
Your local building merchant may be able to assist you in the selection of the right type of material. You may also want to consult the Technical Data sheet for the product or speak to the producer.
This type of product is easy to use and very economically. Most EU countries will have several producers of this type of render. With the correct preparation of your particular substrate (surface) you will be able to re-render existing surfaces, including gypsum walls, existing renders and well adhering previously painted surfaces.
If you do this for the first time it is recommended to test the product on a sample area for suitablity at your project location.
In summary, the two most important attributes of the thin coat render you should select for lime wash painting is that it is adhering well and is able to absorb the lime wash paint.
This is what you need to consider when applying thin coat renders:
- Ensure you finished all repairs before applying on coat of thin coat render. Apply to a thickness of around 2 mm, allow some time to cure and use a sponge float to finish. If you like a surface that is smooth to the touch, but still slightly textured use a stainless steal trowel and at the right time push all grains that are proud of the surface back level to the surface.
- Allow to cure and protect the surface from all sorts of contamination, such as grease, fat, oil, wax, but also acrylic gap fillers or paint when painting door surrounds or architraves.
- Brush off dust and all loose particles prior to applying two coats of limewash paint. There is no need for any primers or Prep Coat.
- 1 litre of limewash will be enough to cover approximately 7 – 10 m² per application. We recommend two coats of limewash paint for such a surface.
Can I paint Limewash Paint on Internal Render walls and what do I need to know?
Bauwerk Limewash paint is ideal for raw masonry interiors where it can be absorbed into the walls leaving a breathable surface that is protected by the natural properties of the paint. With no undercoat or sealer required, the process is quick and simple.
Surface Requirements:
Step 1 Brush down the wall.
Step 2 Dampen walls with clean water using a brush or light mist spray to ensure easy application of limewash.
Paint Application:
Step 3 Apply 2 coats of Bauwerk Limewash using a Bauwerk natural fibre brush. Dip the brush into the bucket and flick off excess paint. The brush can hold a lot of paint, but should not be dripping.
Using loose, free strokes, stretch the paint as far as possible in all directions. Maintain a wer edge at all times to prevent colour overlays. Do not leave drips or runs. Continue to stir the paint regularly while painting.
Allow 1-2 hours between coats. When wet, the colour will appear darker and transparent. As the paint dries the colour will lighten and become opague.
Find here specifications and certificates for our paint or watch our guide on how to paint a render masonry wall here or at the bottom of the page
Tip:
With large expanses, it helps to work to a natural break in the wall such as a mortar joint or V joint or with the assistance of another person.
During construction or renovation, it is advisable to schedule Bauwerk painting as the final trade to prevent damage to the final finish caused by other trades or building equipment.
Number of Coats:
Two coats usually suffice.
Weather:
The ideal temperature for applying Bauwerk Limewash is 8°C-30°C (46°F-86°F)
Do not paint if the surface and/or air temperature falls below 5°C (41°F) during application or curing.
What do I need to consider when painting on external render?
External cement render can easily be painted with limewash paint
Surface Requirements:
External cement rendered surfaces should be free from any dirt and dust, finished to the standard that does not require additional coatings (ie crack-free). It also should be free from absorption limiting substances, such as acrylic gap sealers, overspray with other paints etc.
Render Application:
External renders are best applied in two coats to avoid ghosting of the block/brick joints. If the wall is free standing allow for a water proof capping with an overhang.
Paint Application:
You can paint directly on to the cement rendered surface, even if it is still damp.
Should the surface be dry and too absorbent to easily stretch out the paint then dampen the surface sufficiently. Do not thin the paint.
Paint wet in wet (always catch the edges before they have dried).
For large areas ensure adequate scaffolding and manpower.
Number of Coats:
Two coats usually suffice.
Weather:
Paint only with a minimum of three clear days without rain or protect the surface from rain after painting. Do not paint if the wall and air temperature is at 5 deg C or below.
What if my internal render wall is already painted, can I still use limewash paint?
Yes, just follow these simple instructions to paint an interior render wall that has previously been painted.
Surface Requirements
Step 1: Make necessary repairs and remove dust and loose particles. Sand well if the previous paint has any level of gloss.
Step 2: If your previously painted walls have been patched or repaired or have a mix of materials over the surfaces, we recommend sealing over these areas with 2 coats of a water-based undercoat-sealer/primer. If large sections of the wall have been repaired it may be best to seal over the entire surface. Sealing the wall ensures a consistent surface and prevents ghosting of patched areas coming through in the final finish.
Paint Application
Step 3: Apply 1 coat of Bauwerk Prep Coat.
Step 4: Apply 2 coats of Bauwerk Limewash Paint using a Bauwerk natural fibre brush. Dip the brush into the bucket and flick off excess paint. The brush can hold a lot of paint, but should not be dripping. Apply 2 coats of Limewash paint using a Bauwerk natural fibre brush. Dip the brush into the bucket and flick off excess paint. The brush can hold a lot of paint, but should not be dripping. Using loose, free strokes, stretch the paint as far as possible in all directions. Maintain a wet edge at all times to prevent colour overlays. Do not leave drips or runs. Continue to stir paint regularly while painting.
Allow 1–2 hours between coats. When wet, the colour will appear darker and transparent. As the paint dries the colour will lighten and become opaque.