• One-coat rendering mortar for internal and external walls
• Pre-mixed from sand, lime, cement and additives, just add water
• Weather resistant and breathable, so walls can breathe while resisting penetrating damp
• Will not chip, flake or peel, and can be hosed down
• Tough and flexible with excellent adhesion
• Certified to EN 998-1; grey, 25 kg

First, make sure the background is sound, clean and suitably prepared. On smooth or low-suction surfaces, key it first with our Plasterers Pregrit (internal) or Exterior Pregrit.

Next, mix a 25 kg bag with 4 to 5 litres of clean water using a mechanical stirrer, keeping the water to a minimum for best strength.

Then apply with a hawk and trowel. On low-suction backgrounds, lay a thin first pass, then build up to full thickness in a second pass.

Finally, rule off and finish as required, and protect from rapid drying. For extra flexibility or a bonding slurry on difficult backgrounds, add our SBR to the mix.

• Product code: BDER25
• Type: pre-mixed one-coat rendering mortar (sand, lime, cement, additives)
• Strength: moderate, for moderate backgrounds and exposure
• Properties: weather resistant, breathable, resists penetrating damp, tough and flexible
• Finish: will not chip, flake or peel; can be hosed down
• Mixing: 4 to 5 L clean water per 25 kg bag
• Standards: EN 998-1
• Colour and size: grey, 25 kg

Is it really a one-coat render?

It is a one-coat rendering mortar built up to full thickness in a pass, or a thin first pass then a second on low-suction backgrounds. It saves the separate scratch and top coats of traditional sand-and-cement render.

Can I use it inside and outside?

Yes, it is for internal and external use, offering moderate strength for moderate backgrounds and exposure conditions.

Does it let the wall breathe?

Yes, it is breathable, so the wall can release moisture while the render still resists penetrating damp from outside.

How much water do I add?

Around 4 to 5 litres of clean water per 25 kg bag, mixed with a mechanical stirrer. Use as little water as possible for the best result.

Do I need to prepare the wall first?

Smooth or low-suction backgrounds should be keyed first, using Plasterers Pregrit internally or Exterior Pregrit outside, so the render grips.

Can I make it more flexible?

Yes, adding our SBR latex to the mix improves flexibility and adhesion, which helps on backgrounds subject to movement.