Composite Front Door Supply and Installation
High-security composite front entrance doors combine 44 mm to 48 mm solid timber or high-density CFC-free polyurethane foam slabs encased in impact-resistant 2 mm glass-reinforced polymer (GRP) skins, delivering whole-doorset Ud values from 0.9 to 1.3 W/m²K under Approved Document L. Certified to PAS 24:2022 and Part Q security standards, each unit incorporates multi-point hook locking, 3-star TS007 anti-snap lock cylinders, and Part M compliant low thresholds with a maximum 15 mm vertical upstand for step-free access.
Window Fitters Ltd supplies and installs premium high-security composite doors for homeowners, landlords, and property developers across Croydon, Surrey, and South West London within our local (under 15 minutes at £540/day) and extended (15 to 45 minutes at £580/day) dispatch tiers from our registered office in Croydon.
We supply two distinct high-performance composite door core constructions: solid cross-laminated timber core doors and high-density insulated polyurethane foam core doors. Every doorset is installed by our directly employed, CSCS-certified glazing teams, fully compliant with Approved Document L (thermal insulation), Approved Document Q (security), and Approved Document K (safety glass).
Core Construction: Solid Timber Core vs High-Density Foam
Understanding the internal engineering of composite doors helps you choose the right balance of physical weight, security, and thermal insulation:
| Core Construction Type | Internal Core Engineering | Thermal Performance (Ud) | Key Structural Characteristics |
|---|---|---|---|
| Solid Timber Core (48 mm thick) | Multi-layered cross-laminated engineered timber encased in 2 mm GRP or thermo-plastic skins | 1.2 to 1.4 W/m²K | Substantial physical weight (45 kg to 55 kg), solid acoustic feel, exceptional resistance to sledgehammer and kicking attacks |
| High-Density Foam Core (44 mm to 70 mm) | High-insulation polyurethane (PUR) foam core surrounded by water-resistant composite stiles and rails | 0.9 to 1.2 W/m²K | Ultra-low thermal transmittance, lightweight operation, ideal for low-energy and Passivhaus homes |
GRP Woodgrain Surface Skins
Impact-resistant Glass Reinforced Plastic (GRP) outer skins featuring authentic woodgrain textures that will never rot, warp, twist, flake, or require repainting.
TS007 3-Star Anti-Snap Locking
Fitted with British Standard Kitemarked 3-star anti-snap lock cylinders, bi-directional steel hook locks, and hinge dog bolts resisting forced physical entry under Approved Document Q.
Part M Low Threshold Options
Thermally broken low aluminium thresholds (15 mm upstand) providing wheelchair and pushchair accessibility conforming to Approved Document M.
Security Hardware: Multi-Point Hooks and TS007 3-Star Cylinders
Every external composite door fitted by Window Fitters Ltd is engineered to resist forced physical attacks under Approved Document Q:
- Multi-point hook locking: Bi-directional high-tensile steel hooks engage into heavy-duty reinforced steel keeps along the full height of the outer frame.
- TS007 3-star anti-snap cylinders: British Standard Kitemarked cylinders featuring a sacrificial external cut line, anti-drill tungsten pins, and anti-pick tumbler pins. View our hardware guide.
- Hinge dog bolts: Interlocking conical steel studs on the hinge side of the leaf lock directly into the frame rebate, preventing door removal even if hinge pins are attacked.
- Safety glazing: All decorative and side-panel glass cassettes feature BS EN 12600 Class 1 toughened safety glass with internal security beading.
Technical Survey & Fitting Tolerances
Our fitters anchor reinforced composite outer frames into structural masonry using direct frame fixings spaced 150 mm from corners and at 600 mm intermediate centres under Approved Document A. Perimeter cavities are insulated with low-expansion polyurethane foam under Document L and sealed with Class 1 neutral-cure silicone under Document C.
Explore our complete entrance door resources: browse our full doors directory, follow our 6-stage door installation workflow, consult certified door fitters, compare premium aluminium options in our Axorra aluminium doors guide, review utility back door alternatives in our uPVC door panels guide, and review our complete installation services directory.
Composite Core Typology Comparison
When selecting a composite door for a residential upgrade, understanding the internal core construction is critical for both security and thermal performance. Window Fitters Ltd installation teams fit all major core types across the UK market, each presenting distinct physical characteristics.
| Brand | Core Technology | Key Characteristics |
|---|---|---|
| Solidor | 48 mm Solid Hardwood | Exceptional structural rigidity, heavy physical weight, premium acoustic reduction, and fitted with Ultion 3-star cylinders as standard. |
| Endurance | Cross-Laminated LVL | Laminated Veneer Lumber (LVL) construction offering immense lateral strength and resistance to bowing. |
| Comp Door | Albasia Falcata / CoolSkin | Premium timber core wrapped in heat-reflective CoolSkin technology to minimise thermal expansion on south-facing elevations. |
| Rockdoor | PU Foam Reinforced | Carbon fibre reinforced inner frame with high-density polyurethane foam, balancing high security with superior thermal efficiency. |
| Truedor / Door-Stop | Standard PU Foam | Lightweight 44 mm foam core providing excellent whole-door Ud values and cost-effective entry-level performance. |
Solidor Installers London
As experienced installers of premium hardwood composite systems, Window Fitters Ltd provides dedicated fitting services for Solidor products across the capital. These 48 mm thick timber core doors demand heavy-duty installation techniques, utilising heavy-duty frame anchors to support the substantial leaf weight. Our teams ensure precise alignment and hinge adjustment to maintain long-term operational tolerances. For existing installations, you can consult our technical guide on how to adjust door hinges.
Labour-Only Installation Pricing
For main contractors, property developers, or homeowners who have sourced their own doorsets, we offer a transparent labour-only installation pathway, typically ranging from £180 to £260 per leaf on multi-door schemes or £240 to £290 for individual residential replacements. This service includes full structural fixing, perimeter weathersealing, and operational commissioning.
- Single Composite Doorset: £240 to £290 per unit (depending on structural preparation requirements).
- Composite Doorset with Toplight or Sidelight: £320 to £380 per unit.
- Day Rate (2-man glazing team): £540 to £580 per day (£540 local, £580 extended; capable of fitting 2-3 standard doorsets).
All installations ensure compliance with Building Regulations, including Part M door thresholds for accessible entry. Our installation teams frequently undertake entrance door upgrades in suburban homes and period conversions; explore our local project work in Sutton, or review riverside property installations in our Richmond door installation guide and broader South West London door installation coverage.
Frequently Asked Questions About Composite Doors
Direct answers to common questions regarding composite door core construction, thermal performance, PAS 24 security hardware, and installation day rates across London and Surrey.
Will a composite front door warp or bow in direct sunlight? +
Our composite doors feature internal cross-laminated engineered timber or reinforced composite stiles that resist thermal expansion and bowing. To maintain alignment on south-facing doors in hot weather, our fitters advise always throwing the handle up when the door is closed to engage all multi-point hooks.
What is the difference between a solid timber core and a foam composite door? +
Solid timber core composite doors feature 48 mm of cross-laminated engineered hardwood providing heavy physical weight (up to 55 kg) and solid acoustic insulation. High-density foam core doors use polyurethane insulation, offering maximum thermal efficiency with lower weight.
What security cylinder is fitted to composite doors? +
We fit British Standard Kitemarked TS007 3-star anti-snap euro cylinders with sacrificial external cut lines, anti-drill tungsten carbide pins, and anti-pick tumbler pins resisting forced physical entry under Approved Document Q.
Author & Technical Reviewer: Marian Gheorghe
Head Installer & CEO, Window Fitters Ltd
Marian Gheorghe is the Active Director and Team Leader Installer at Window Fitters Ltd. With over 15 years of hands-on experience, he oversees technical safety and UK Building Regulations compliance for all residential and commercial glazing contracts.
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Window Fitters Ltd provides window and door installations across London and Surrey for residential, trade, and commercial projects.
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Verified Google & MyBuilder Reviews
"Stunning Sash Windows in Croydon"
"Marian and his team replaced our old Victorian sash windows. They were clean, fast, and the double glazing has completely blocked out the street noise. Highly recommended!"
"Excellent Bifold Doors in Bromley"
"Installed beautiful grey aluminium bifold doors for our new kitchen extension. Smooth gliding mechanism and great insulation. The best quote we got in Kent."
"Perfect Front Door Upgrade in Sutton"
"Very happy with our new composite door installation. Excellent lock security and high-quality GRP slab finish. Fast half-day fitting and no mess left behind."