DIBLU POLYSTYRENE 160MM / PACK 100 PCS

POLYSTYRENE DOWEL 160MM

A 160mm polystyrene dowel is a specialised component used in External Thermal Insulation Composite Systems (ETICS) for the mechanical fixing of expanded polystyrene (EPS), extruded polystyrene (XPS) or, in rare cases, mineral wool to substrates such as concrete, solid brick, hollow brick, BCA or other building materials. Designed to provide a stable and durable anchorage, this dowel resists external forces such as wind, thermal variations or the weight of the thermal insulation system. Due to its shorter length, it is ideal for very thin insulation thicknesses, making it an efficient and economical solution compared to dowels of 180 mm, 200 mm, 220 mm, 240 mm, 240 mm, 260 mm or 300 mm.

Detailed description

1. Composition and materials

• Main body: Made of high quality polypropylene (PP) or polyethylene (PE), sometimes reinforced with fibres to increase mechanical strength. The plastic prevents thermal bridging, reducing heat loss and contributing to the energy efficiency of the building.
• Fixing nails: Available in galvanised steel for superior corrosion resistance and solid anchorage or reinforced plastic for less demanding applications. Metal nails are favoured for hard substrates or harsh environmental conditions, and heat-capped designs reduce heat transfer through the nail.
• Flange (rosette): The upper part of the dowel, with a standard diameter of 60-65 mm, which presses the polystyrene board against the substrate surface. The flange evenly distributes the pressure to prevent damage to the insulating material.
• Expansion Area: Located at the bottom, this area expands into the backing material to ensure a firm hold. Some designs include multiple expansion zones, effective in porous or hollow materials such as cavity brick.

2. Dimensions and technical specifications

• Overall length: 160 mm, suitable for 2-10 cm thick polystyrene boards, taking into account the adhesive layer (5-10 mm) and any minimal additional layers (e.g. very thin existing plaster).
• Diameter: The dowel body is typically 10 mm in diameter, compatible with standard drill bits.
• Depth of anchorage: Minimum 50 mm in the supporting material (concrete, brick, etc.), according to the pull-out strength standards. The drilled hole must be 10 mm deeper than the anchorage length for correct fixing.
• Pull-out strength: Depends on the type of substrate, e.g. may exceed 1 kN in concrete, but is lower in BCA or hollow brick, where specialised designs may be required.

3. Uses and applications

The 160 mm dowel is mainly used for:

• Fixing thermal insulation boards in facade systems, particularly for minor refurbishments or extremely thin insulation thickness construction where thermal requirements are minimal.
• Various substrates: concrete, solid brick, hollow brick, BCA, porous concrete or, in rare cases, wood/OSB (with suitable screws).
• Low-rise buildings (under 25 m according to local regulations), where 4-6 dowels per square metre are recommended, depending on the technical design.
• Plinth area: For extruded polystyrene used at the plinth, dowelling should start at least 30 cm above the ground to avoid contact with moisture.
• Special applications: Can be used in interior insulation projects or in areas with low thermal requirements, such as garages, outbuildings or buildings in hot climate regions.

4. Advantages

• Thermal efficiency: The plastic material reduces thermal bridges, contributing to better thermal insulation.
• Mechanical resistance: Provides stability even in windy conditions or temperature variations.
• Versatility: Compatible with most substrates and insulation types.
• Quick installation: Easily installed with a rotary hammer for drilling and a hammer for hammering the nail, without complex tools.
• Durability: Resistant to corrosion (galvanised nails) and degradation caused by moisture or chemicals.
• Economy: The shorter length makes the dowel an affordable solution for projects with limited budgets or low thermal requirements.

5. Installation instructions

1. Surface preparation: The polystyrene boards are glued with special adhesive and left to harden (24-48 hours).
2. Drilling: Use a 10 mm drill bit to create a hole through the polystyrene and a minimum of 50 mm in the substrate. The hole should be 10 mm deeper than the anchor length.
3. Inserting the dowel: Insert the body of the dowel until the flange touches the surface of the polystyrene sheet.
4. Fastening the nail: Tap the nail (metal or plastic) with a hammer or screw it in until the flange presses firmly against the board without deforming it.
5. Covering: Cover the flanges with reinforcing mesh and decorative plaster coats for exterior facades.

6. Recommendations and standards

• Number of dowels: Minimum 4-6 dowels/sq.m for buildings under 25 m, according to project requirements.
• Length calculation: Thickness of polystyrene + thickness of existing adhesive/tense + minimum 50 mm for anchorage.
• Certifications: Opt for European Technical Approval (ETA) dowels to meet building standards.
• Correct installation: Avoid excessive tapping, which can damage the polystyrene board, or insufficient drilling, which reduces strength.

7. Special features of the 160 mm dowel

• Optimum for extremely thin insulation thicknesses (2-10 cm), common in cosmetic renovations, buildings with minimal thermal requirements, interior insulation or areas with very mild climates.
• The 160 mm length is suitable for substrates with no or minimal additional layers (e.g. without thick old plaster).
• Some models include depth markings or optimised design for fast and accurate installation.

8. Limitations and precautions

• Brittle substrates: In very porous or weak materials (e.g. porous BCA, old brick), pullout resistance may be reduced, requiring specialised tests or dowels.
• Incorrect assembly: Too wide a hole or insufficient anchorage compromises fixing.
• Compatibility: Shorter lengths may be insufficient for thicker insulation or extra layered supports, requiring careful checking of overall thickness.
• Thermal requirements: For buildings with higher insulation needs, the thickness of insulation supported by this dowel may be inadequate by modern energy efficiency standards.

9. Comparison with dowels of 180 mm, 200 mm, 220 mm, 240 mm, 260 mm and 300 mm

• Length: The 160 mm dowel is shorter than the 180 mm (by 20 mm), 200 mm (by 40 mm), 220 mm (by 60 mm), 240 mm (by 80 mm), 260 mm (by 100 mm) and 300 mm (by 140 mm) dowels, and is suitable for insulation thicknesses of 2-10 cm, compared to 4-12 cm (180 mm), 6-14 cm (200 mm), 8-16 cm (220 mm), 10-18 cm (240 mm), 12-20 cm (260 mm) or 15-25 cm (300 mm).
• Use: Ideal for extremely thinly insulated projects such as minor renovations, interior insulation, outbuildings, garages or buildings in warm climates where additional thermal insulation is minimal.
• Strength: Similar performance provided the minimum anchorage depth (50 mm) is respected. The 160 mm is preferred for applications with low thermal and mechanical requirements.

Conclusion

The 160 mm polystyrene dowel is a practical and extremely economical solution for fixing thermal insulation boards in facade systems or interior applications, ideal for very thin insulation thicknesses (2-10 cm). With a design that minimises thermal bridging and provides adequate mechanical strength, this dowel is perfect for minor renovations, buildings with low energy requirements, interior insulation or mild climate zones. Choosing a certified model and following the installation instructions are crucial to ensure the durability and performance of the thermal insulation system.