Product Overview:
Cement-free, highly diffusion-open mineral insulating render for manual and machine application for internal and external use. Thermal insulation render mortar T 1 and CS I according to DIN EN 998-1.
Composition Aggregate:
Natural hydraulic building lime, mineral lightweight aggregate and additives for better processing.
Properties
• Heat-insulating basecoat with mineral lightweight aggregates.
• Non-combustible.
• Machine applicable, mineral insulating render with increased flexibility.
• Temperature and moisture regulating with excellent water vapour permeability.
• Suitable for machine and hand application.
Application
• Thermally insulating render mortar for use as a base coat on mineral substrates for internal and external use.
• Due to its cement-free formulation, it is ideally suited for use in listed or historic buildings.
• For single- or multi-layer application in old and new buildings, timber-framed buildings, masonry as well as concrete, when using a suitable bonding agent.
• For levelling uneven substrates.
Technical Data
• Reaction to fire: A1
• Compression strength: > 0.5 N/mm²
• Strength category: CS I according to DIN EN 998-1
• Adhesive tensile strength: ≥ 0.08 N/mm²
• μ-value = ≤ 8
• Water absorption: Wc 0 according to DIN EN 998-1
• Thermal conductivity: ≤ 0.075 W/mK
• NHL Thermo 14.5kg (40L)
• yield = app. 2.6 m²/bag at a layer thickness of 15mm
• yield = app. 1.3 m²/bag at a layer thickness of 30mm
• Grain = 0.2 mm
• Min. application thickness = 15 mm
• Max. application thickness = 30 mm In one pass
• Consumption = App. 0.37 kg/m²/mm
• Water requirement = App. 16 l/bag
| Weight | 14.6 kg |
|---|---|
| Dimensions | 58 × 40 × 14 cm |
FAQs
Frequently Asked Questions – Baumit NHL Thermo
What is Baumit NHL Thermo?
Baumit NHL Thermo is a cement-free, heat-insulating lime render made with natural hydraulic lime (NHL) and lightweight mineral aggregates. It is designed to improve thermal performance while remaining highly breathable, making it ideal for both historic and modern buildings.
Is NHL Thermo suitable for listed or historic buildings?
Yes. Baumit NHL Thermo is cement-free and highly vapour permeable, which makes it particularly suitable for listed buildings, heritage properties, and traditional solid-wall construction, where breathability and moisture regulation are essential.
Can Baumit NHL Thermo be used internally and externally?
Yes. NHL Thermo can be applied as a basecoat render for both internal and external walls, provided the substrate is mineral and correctly prepared.
How does NHL Thermo improve thermal performance?
NHL Thermo has a low thermal conductivity of ≤ 0.075 W/mK, helping to reduce heat loss through solid walls while still allowing moisture vapour to pass through the structure.
Is Baumit NHL Thermo breathable?
Very much so. NHL Thermo has a μ-value of ≤ 8, meaning it is highly vapour open. This allows walls to “breathe,” helping to regulate internal humidity and reduce the risk of condensation and trapped moisture.
Is NHL Thermo fire resistant?
Yes. Baumit NHL Thermo is classified as A1 non-combustible, meaning it does not contribute to fire spread.
What substrates can NHL Thermo be applied to?
NHL Thermo can be applied to:
• Masonry
• Solid brick and stone
• Concrete (with suitable bonding agent)
• Timber-framed buildings
• Mixed and uneven mineral substrates
• Correct substrate preparation and priming are essential.
What is the minimum and maximum application thickness?
• Minimum thickness: 15 mm
• Maximum thickness in one pass: 30 mm
• Greater overall thicknesses are possible when applied in multiple layers in accordance with manufacturer guidance.
How much coverage does a bag of NHL Thermo give?
A 14.6kg bag provides approximately:
• 2.6 m² at 15 mm thickness
• 1.3 m² at 30 mm thickness
• Coverage will vary depending on substrate condition and application method.
Can NHL Thermo be machine applied?
Yes. Baumit NHL Thermo is suitable for both hand and machine application. When machine applied, specialist insulating render equipment should be used, and test areas are recommended.
Is NHL Thermo suitable as a finishing render?
No. NHL Thermo is a basecoat insulating render and must be finished with a suitable reinforcing layer and breathable finishing render or paint.
Can tiles be fixed directly onto NHL Thermo?
No. Due to its low compressive strength, NHL Thermo is not suitable for fixing tiles or slabs directly.
Does NHL Thermo regulate moisture?
Yes. NHL Thermo is designed to be moisture-regulating, allowing water vapour to pass through while helping to create a more stable and comfortable internal environment.
How long does NHL Thermo take to dry?
Drying time depends on thickness and conditions. As a general guide:
• Allow approximately 1 day per 10 mm of thickness
• A minimum of 1 week drying time before applying finishing coats is recommended, especially in cooler conditions
Is NHL Thermo suitable for plinth or ground-level areas?
No. Baumit NHL Thermo should not be used in plinth areas or where it may be exposed to persistent moisture or splashback.
What makes NHL Thermo different from standard lime render?
Unlike standard lime renders, NHL Thermo combines thermal insulation, vapour permeability, and flexibility in one product, making it especially effective for upgrading the thermal performance of solid walls without compromising breathability.
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