ROCKWOOL ROCKFLOOR 25mm Acoustic & Thermal Floor Slab

is a semi-rigid stone wool insulation slab intended for floor insulation and acoustic floor build-ups. It gives builders, installers and property owners a practical way to improve thermal performance while using a product developed for the relevant construction type rather than a generic substitute.

The product is supplied in 1200 x 1000mm format, with Check pack coverage. Its declared thermal performance is Product-specific. Select the thickness by reference to the full construction, target U-value, available build-up and project specification. The insulation should be used as one component of a complete system; performance depends on correct detailing at joints, edges, openings and penetrations.

This page is written for trade buyers who generally know the product family but need clear information on sizes, applications, installation, accessories and alternatives. It avoids presenting a single board or roll as a guaranteed Building Regulations solution because compliance is determined by the complete construction.

Product Snapshot

Key Features

·        Designed specifically for floor insulation and acoustic floor build-ups

·        1200 x 1000mm product format

·        Check pack coverage coverage information shown clearly

·        Thermal performance: Product-specific

·        Suitable for professional and competent DIY installation where the construction permits

·        Can be combined with the correct accessories to create a continuous dense thermal and acoustic infill

·        Available in multiple thicknesses or formats where listed

·        Suitable for new-build, refurbishment and upgrade work subject to specification

Common Uses

·        Walls, floors and ceilings

·        Residential refurbishment and extensions

·        New-build housing and commercial projects

·        Thermal upgrades where the selected thickness is supported by a U-value calculation

·        Projects requiring a recognised manufacturer product and clear technical documentation

Technical Specifications

Which Variant Should I Choose?

Choose the variant by balancing the required thermal resistance, available depth, pack coverage, handling and the project specification. Do not select thickness from price alone.

25mm - suitable where this thickness or format matches the designed construction. Check U-value calculations, junction details and stock availability before ordering large quantities.

Good to Know

·        Store the product dry, flat and protected from damage before installation.

·        Measure the net area and add a sensible allowance for cuts and waste.

·        Maintain continuity at corners, junctions, openings and service penetrations.

·        Do not assume a thicker product automatically resolves condensation, fire or acoustic requirements.

·        Use the latest manufacturer datasheet and system guidance where performance is specification-critical.

Installation Guidance

1.      Check that the substrate or supporting construction is stable, dry and suitable for the proposed system.

2.      Plan the layout so the dense thermal and acoustic infill remains continuous and unnecessary narrow cuts are avoided.

3.      Cut accurately with tools suitable for the material and wear the recommended PPE.

4.      Fit boards, slabs or rolls closely together without avoidable gaps, compression or distortion.

5.      Stagger joints where the system design requires it and seal or tape interfaces using compatible products.

6.      Use only the specified adhesive, mechanical fixings, retainers, battens or support system.

7.      Detail perimeters, openings, penetrations and changes of plane carefully to reduce thermal bridging and air leakage.

8.      Protect completed work and install the next layer promptly in accordance with the manufacturer or system instructions.

Common Mistakes to Avoid

·        Using the wrong product family for the construction.

·        Leaving open joints or poorly fitted perimeter gaps.

·        Compressing mineral wool rolls or slabs below their intended thickness.

·        Mixing unverified adhesives, renders, membranes or waterproofing components.

·        Ignoring ventilation, vapour control, condensation risk or fire requirements.

·        Ordering by board count without checking pack coverage and waste.

Complete Your Project

Products commonly required with this semi-rigid stone wool insulation slab include:

·        Acoustic Plasterboard

·        Floor Boards

·        Sealant

·        Fixings And Perimeter Isolation

Have You Considered These Products?

ROCKWOOL ROCKFLOOR 30mm - compare application, thermal performance, board format, availability and total installed cost before substituting.

ROCKWOOL ROCKFLOOR 50mm - compare application, thermal performance, board format, availability and total installed cost before substituting.

Rockwool RWA45 - compare application, thermal performance, board format, availability and total installed cost before substituting.

Frequently Asked Questions

What is ROCKWOOL ROCKFLOOR used for?

It is primarily used for floor insulation and acoustic floor build-ups. Use it only where the complete construction and manufacturer guidance support that application.

How do I choose the correct thickness?

Use the project specification or a U-value calculation. Available depth, junctions, condensation risk and Building Regulations also affect the final choice.

Is the price per board, roll or pack?

The pricing table identifies the operational selling unit for each variant. Confirm pack quantities before placing a large order because manufacturer pack sizes can vary by thickness.

Can I substitute another insulation product?

Only after checking application, thermal conductivity, compressive strength, fire classification, facing, dimensions and compatibility with the complete system.

What else should I order?

Review the Complete Your Project section and the installation specification. Tapes, sealants, fixings, membranes, adhesives or supporting boards are often required.

Does this product meet Building Regulations?

The product can contribute to a compliant construction, but the board or roll alone does not guarantee compliance. The complete wall, floor or roof build-up must be assessed.

Can I install it myself?

Some straightforward applications are suitable for competent DIY installation. Specialist EWI, cavity, flat-roof, waterproofing and fire-sensitive systems should be installed by appropriately experienced contractors.