Baumit Base Coats for Medium Density Blockwork

Medium-density blocks can provide a suitable background for mineral render, although suction and surface texture may vary between block types and manufacturers. Selecting an appropriate base coat and preparing the masonry correctly helps produce even drying, reliable adhesion and a consistent surface for the chosen finish.

This Baumit range includes a general-purpose lime-cement render for masonry and reinforcing mesh for use where additional crack resistance is specified.

Products in This Range

• Baumit KZP 65 – A general-purpose lime-cement render suitable for manual or machine application. It can be used on most types of masonry and forms part of the Baumit UniRend system.
• Baumit StarTex Fine – A fine, non-slip and alkali-resistant glass-fibre mesh designed for embedding within compatible Baumit adhesive and levelling compounds.

Typical Applications

These products may support:

• Rendering suitable medium-density blockwork
• Creating an even base for decorative finishes
• Manual or machine-applied render projects
• Reinforcing vulnerable areas where specified
• Internal and external masonry applications
• New-build and refurbishment work

Preparing Medium-Density Blocks

Blockwork must be sound, stable and sufficiently cured before rendering begins. Remove dust, loose mortar, efflorescence, oil and other contamination that could affect adhesion.

The suction of the blockwork should be assessed before application. Highly absorbent substrates may require Baumit MultiPrimer or application in two passes, while highly absorbent or mixed masonry may require Baumit SuperPrimer or a suitable splatter-dash treatment. Smooth backgrounds can require additional preparation to provide an adequate key.

Using Reinforcement Mesh

Reinforcement may be required across mixed backgrounds, around openings or in other areas where stress and cracking are more likely. Baumit StarTex Fine must be completely embedded within a compatible Baumit reinforcement or levelling compound, with suitable overlaps between adjoining sections.

The mesh is not a standalone coating and should not be fixed directly to the blockwork without the specified embedding material.

Choosing the Correct System

“Medium density” covers blocks with differing strengths, textures and suction levels. Confirm the exact block specification before choosing the preparation and render system.

Always follow the current Baumit technical data sheets for substrate treatment, application thickness, drying periods, reinforcement requirements and compatible primers and finishes.