Metal frame drylining
Galvanised steel tracks and studs + rock wool or glass wool between studs + BA13 board. Integrated air gap. Best acoustic performance. Footprint 7 to 14 cm.
Interior insulation — WallsInterior
Interior
Wall Insulation
Metal frame drylining or bonded PIR composites — Knauf, ISOVER, Rockwool, Recticel. R ≥ 3.7 guaranteed. The solution when ETICS is not feasible. Luxembourg and Greater Region.
R ≥ 3.7 m²·K/WKnauf · ISOVER · RockwoolNo exterior workFrame or bonded
R ≥ 3.7Guaranteed performance
6-14 cmWall thickness
25%Wall heat loss
Why interior insulation?
Interior insulation: when ETICS is not feasible.
Interior thermal insulation (ITI) is the solution when ETICS is impossible — listed facade, co-ownership without vote, constrained budget, or simply a partial renovation project. QUASART carries out two types of ITI: metal frame drylining (with air gap) and insulation composites bonded directly to the wall.
QUASART, based in Crauthem (L-3327), optimises thickness to achieve R ≥ 3.7 with minimal footprint — typically 6 to 12 cm depending on the chosen insulation. Financial subsidies are available through the myenergy programme (Klimabonus) — visit myenergy.lu to check your eligibility.
Interior Insulation · Technical sheet
Données certifiéesThermal performance8.0
Minimal footprint8.5
Installation speed8.0
Acoustic treatment8.5
Thermal bridgesResidual (floors)
Lifespan30-40 years
SystemsMetal frame drylining or bonded insulation composite (PIR, rock wool)
Total footprint6 to 14 cm depending on system and insulation thickness
PerformanceR ≥ 3.7 m²·K/W — eligible for Luxembourg subsidies
Common insulantsRock wool (λ 0.035), PIR (λ 0.022), glass wool (λ 0.032), EPS (λ 0.032)
FinishStandard BA13 board, BA15 (moisture), Fermacell, cement board
Vapour barrierIntegrated in bonded composite or membrane applied on framework
DTU 25.41DTU 25.42EN 13162EN 13165ACERMIRE 2020 / GPE
Insulation materials
Four insulation materials for ITI
The choice depends on available space, budget and acoustic requirements.
01 / INSULATION MATERIALS
HD Rock wool
Rockwool Rockmur, Alphamur — λ 0.035Thermal7.5
Acoustic9.5
Footprint6.0
High-density panel on metal framework. Best acoustic performance for interior insulation. Non-combustible A1. Thickness 45 to 100 mm. Recommended for party walls and apartment buildings.
Acoustic02 / INSULATION MATERIALS
PIR (polyisocyanurate)
Recticel Eurowall, IKO Enertherm — λ 0.022Thermal10.0
Acoustic5.0
Footprint10.0
Lowest lambda on the market (0.022). PIR composite + plasterboard bonded directly to the wall. R ≥ 3.7 in just 80 mm. Ideal for rooms where every centimetre counts. Integrated vapour barrier.
Minimal footprint03 / INSULATION MATERIALS
Glass wool
ISOVER GR 32, Knauf TI 132 — λ 0.032Thermal8.5
Acoustic7.5
Footprint7.0
Semi-rigid panel between metal framework. Good thermal/acoustic/cost compromise. Widely used for external wall drylining. Dust-free treatment and formaldehyde-free binder (ECOSE).
Versatile04 / INSULATION MATERIALS
Elasticised EPS
Knauf Therm, BASF Neopor — λ 0.030-0.032Thermal8.0
Acoustic4.0
Footprint8.5
Elasticised expanded polystyrene — economical bonded composite solution. Lambda 0.030-0.032 depending on grade. No significant acoustic benefit — reserved for external walls without sound requirements.
EconomicalFinishes & cladding
From standard board to technical cladding.
The finishing board depends on the room use and moisture constraints.
Standard
Standard BA13Plasterboard — universal finish
Moisture-resistant
Moisture-resistant BA13Bathroom, kitchen — moisture resistance
Acoustic
Acoustic BA15High density — sound attenuation
Fermacell
Fermacell fibre-gypsumSuperior mechanical resistance
Cement
Cement boardHigh-moisture rooms, utility rooms
Decorative
Decorative claddingStone veneer, brick slips — on drylining
Referenced manufacturers
Four manufacturers. Interior insulation mastered.
QUASART works with European leaders in interior drylining systems.
Germany · Complete systemsGermany · Complete system · Profiles
KNAUF
TI 132 · Therm · ProfilesComplete drylining systems — insulation, metal profiles, plasterboards. Knauf TI 132 (high-performance glass wool), Knauf Therm (EPS), Knauf metal profiles. Vertical integration from rail to paint.
TI 132 — glass wool λ 0.032
Therm — EPS and graphite EPS
Knauf metal profiles
Integrated technical documentation
France · Glass woolFrance · Optima · Saint-Gobain
ISOVER (Saint-Gobain)
GR 32 · Optima · CalibelISOVER range for interior drylining. GR 32 (panel lambda 0.032), Optima (dedicated framework system), Calibel (bonded composite with vapour barrier). Optima system = framework + insulation + membrane in one coherent system.
GR 32 — panel lambda 0.032
Optima — integrated framework system
Calibel — ready-to-install bonded composite
Vario Duplex — hygro-regulating membrane
Denmark · Rock woolDenmark · Fire A1 · Collective
ROCKWOOL
Rockmur · Alphamur · LabelrockHigh-density rock wool panels for wall drylining. Rockmur (standard), Alphamur (high performance), Labelrock (bonded composite). Non-combustible A1, excellent sound attenuation. The choice for apartment buildings.
Rockmur — standard framework panel
Alphamur — high performance λ 0.034
Labelrock — ready-to-install bonded composite
Fire A1 · High Rw+C acoustic rating
Belgium · High-performance PIRBelgium · PIR · Lambda 0.022
RECTICEL
Eurowall · Powerwall · EurothanePIR (polyisocyanurate) panels — the lowest lambda on the market (0.022). Eurowall (bonded drylining), Powerwall (framework), Eurothane (roof). R ≥ 3.7 in just 80 mm. Integrated aluminium vapour barrier. Manufactured in Belgium.
Eurowall — bonded PIR composite, lambda 0.022
Powerwall — PIR on metal framework
R ≥ 3.7 in 80 mm — minimal footprint
Manufactured Belgium — logistic proximity
ITI systems
Framework or bonded — the choice depends on the substrate.
Bonded PIR composite
PIR composite panel + plasterboard, bonded directly to the wall. Minimal footprint — 5 to 8 cm for R ≥ 3.7. Ideal for small rooms. Integrated aluminium vapour barrier.
Bonded rock wool composite
Rockwool Labelrock — HD rock wool + plasterboard bonded on dabs. More vapour-permeable than PIR — recommended for damp walls and natural stone masonry.
Thermal bridge treatment
Thermal bridges (wall/floor junctions, window reveals) are treated with insulating profiles or spray foam. Without this treatment, gains are limited to 60-70% of potential.
Complete finishes
BA13, moisture-resistant BA15, Fermacell — then jointing, skim, paint. QUASART handles all work from track to paint finish. One point of contact, one project.
Subsidies & grants
Financial subsidies are available through myenergy (Klimabonus) for ITI with R ≥ 3.7 m²·K/W. Visit myenergy.lu to check your eligibility.
Installation process
Interior drylining steps
ITI installation requires attention to thermal bridges and airtightness.
01
Substrate diagnosis
Moisture, flatness and crack checks. Adhesion test for bonding. If the wall is damp, pre-treatment (drainage, injection) before any drylining.
Moisture · Flatness · Cracks02
Framework or bonding
Framework: fixing top/bottom tracks + studs every 60 cm. Insulation between studs. Bonding: dab or full adhesive on PIR/wool composite, pressed onto wall.
60 cm · Dabs · Pressing03
Thermal bridges & airtightness
Insulation return at window reveals (min. 20 mm). Resilient peripheral strip at floor/ceiling. Spray foam at service penetrations. Vapour barrier membrane if on framework.
Reveals · Resilient · Membrane04
Board & finishes
Board screwing on framework or adhesion check on bonded composite. Jointing tape, skim coat, paint or wall covering. Surface-mounted sockets and switches.
Screwing · Jointing · FinishTechnical standards
Standards & certifications
Every QUASART drylining complies with applicable DTU standards and regulations.
DTU 25.41
Plasterboard works
Reference DTU for plasterboard facing works — metal frameworks, fixings, jointing, singular points.
DTU 25.42
Drylining works
DTU applicable to wall drylining with bonded composites (EPS, PIR, rock wool + plasterboard). Bonding, layout, junctions.
EN 13162
Mineral wool
European standard for mineral wool insulation panels — declared lambda, thermal resistance, fire behaviour, water absorption.
EN 13165
PIR/PUR panels
European standard for polyurethane/polyisocyanurate insulation panels — lambda, thermal resistance, dimensional stability, fire behaviour.
ACERMI
Performance certification
Certified thermal certification — guaranteed lambda and ISOLE rating. Essential for subsidy application files.
RE 2020 / GPE
Energy performance
Current thermal regulation — R ≥ 3.7 m²·K/W minimum for walls in subsidised renovation in Luxembourg.
Areas of application
Interior insulation — for which projects?
01
Listed or protected facades
When ETICS is prohibited by the municipality or heritage listing — ITI is the only option to achieve R ≥ 3.7. Bonded PIR composite to minimise footprint on living area.
02
Apartment renovation
Insulation of external-facing walls in a co-owned apartment — without general assembly vote, without touching the facades. The owner decides alone on interior works.
03
Specific rooms
Insulation of a single room (cold bedroom, office) without renovating the whole building. ITI allows targeted, fast and cost-effective intervention.
04
Partial ETICS complement
When ETICS does not cover all walls (party wall, inaccessible blank wall) — ITI completes the overall thermal performance of the building.
Selected projects
Interior insulation in practice
Recticel Eurowall PIR 80mm bonded
Heritage · 2024Apartment Ville-HauteLuxembourg City
Rockwool Rockmur 100mm framework
Renovation · 2024House StrassenStrassen, Luxembourg
ISOVER GR 32 Optima 120mm
Commercial · 2023Office KirchbergKirchberg, Luxembourg
Knauf TI 132 + BA13
Co-ownership · 2024Apartment GasperichGasperich, Luxembourg
Recticel Powerwall PIR 100mm
Residential · 2023House EschEsch-sur-Alzette, Luxembourg
Rockwool Alphamur + acoustic BA15
Commercial · 2023Practice ThionvilleThionville, France
Interior insulation is not a compromise — it is the smart solution when the exterior is not accessible. 80 mm of PIR is enough to transform wall comfort.QUASART — Philosophie de la mise en œuvre
FAQ
Interior insulation FAQ
Everything you need to know
No — ETICS remains the thermally superior solution as it eliminates structural thermal bridges (floors, partitions). ITI achieves R ≥ 3.7 but retains residual thermal bridges. However, it remains effective and represents a significant improvement over an uninsulated wall.
From 6 to 14 cm depending on the system. A bonded PIR composite (Recticel Eurowall) achieves R ≥ 3.7 in 7-8 cm. A framework drylining with 100 mm rock wool takes approximately 12-14 cm. In a 3×4 m room, that is 0.5 to 1.4 m² lost.
No — a damp wall must be treated before any drylining (drainage, resin injection, renovation render). Installing drylining on a damp wall traps moisture and creates mould. QUASART systematically carries out a moisture diagnosis before specification.
Financial subsidies exist in Luxembourg for wall insulation. The myenergy programme (Klimabonus) can cover part of your investment if R ≥ 3.7 m²·K/W. Visit myenergy.lu to check your eligibility.
With a bonded PIR composite: the aluminium vapour barrier is integrated into the panel. With framework drylining: a vapour barrier membrane (Sd ≥ 18 m) is recommended on the warm side, especially if the insulation is permeable (mineral wool). The Sd rule is critical to prevent condensation.
PIR (λ 0.022) offers the best thermal performance at minimal thickness — ideal when space is constrained. Rock wool (λ 0.035) is less thermally efficient but acoustically excellent and non-combustible (A1). QUASART recommends PIR for small rooms and rock wool for apartment buildings.
Areas of operation