Rigid Foam Board Insulation
Premium, high-performance solution for maximum thermal resistance and structural strength
Rigid foam board insulation is a premium, high‑performance solution for lofts, roofs, walls, and floors where space is limited, maximum thermal resistance is required, or structural strength matters. At Loft Insulation Services UK, our rigid foam board insulation service delivers expert installation, long-lasting performance, and energy savings — ideal for loft conversions, flat roofs, extensions, or homes needing optimal thermal efficiency.
Whether you're planning a loft conversion, upgrading insulation in a modern build, renovating a roof or wall, or simply aiming for long-term energy savings — rigid foam board can provide a solid, stable, and efficient insulation solution that meets high standards and delivers comfort year-round.
Why Choose Rigid Foam Board Insulation
Rigid foam board insulation stands out because of its unique combination of thermal performance, structural strength, and versatility. Here's what makes it a top choice for many projects:
Key advantages of rigid foam boards:
High thermal resistance per thickness
Foam boards offer a very good U‑value even with relatively thin profiles, making them ideal where roofspace, wall cavity, or floor height is limited.
Structural stability and load-bearing capacity
Unlike loose‑fill or rolls, foam boards remain rigid — enabling them to support flooring, roof decks, or wall overlays without sagging or compression. Excellent for loft conversions, solid floor overlays, or roof renovations.
Moisture resistance and water‑tightness
Closed-cell foam boards resist water absorption, helping prevent damp, condensation, and thermal bridging — especially useful in roofs, flat ceilings, or walls exposed to moisture or external weather conditions.
Consistent performance over time
Foam boards don't settle, compress, or degrade easily — they maintain their insulation value for decades if installed correctly.
Versatile application
Suitable for flat roofs, pitched roofs under rafters, external wall insulation, internal wall overlays, floors (over joists or concrete slabs), basement ceilings, and more.
Improved airtightness and comfort
Because boards are rigid and fitted snugly (with sealing at joints), they help create a continuous thermal envelope — reducing drafts, noise infiltration, and improving energy efficiency.
Our Rigid Foam Board Insulation Services
We provide a comprehensive rigid-foam‑board insulation service — from the initial survey to installation and aftercare — ensuring correct specification, safe installation, and long-term performance.
1. Detailed Property & Structural Assessment
- Examine the building's structure — roof pitch, wall construction, floor type (suspended or concrete), existing insulation, moisture risk, ventilation, and load-bearing requirements.
- Determine appropriate foam board type (e.g. PIR, XPS, EPS) and thickness for the installation based on thermal performance required, structural load, and regulatory standards.
- Check for potential obstructions — water tanks, wiring, pipes, vents, chimneys — and plan cuttings/overlaps accordingly.
2. Preparation & Moisture / Ventilation Planning
- Ensure roof/wall/floor surfaces are dry, clean, and structurally sound before board installation.
- Where needed, install vapour control layers or membranes to manage moisture ingress and condensation risk — especially in roofs or basement ceilings.
- Verify ventilation or airflow requirements (e.g. soffit vents for pitched roofs, external wall vents) remain functional after foam board installation.
3. Precise Installation of Foam Boards
- Cut boards accurately to fit between rafters, joists, or wall studs — ensuring snug fit and minimal gaps.
- Secure boards with appropriate fixings (mechanical fixings, adhesive, screws — depending on wall/roof/floor type) to ensure stability.
- Seal all joints, edges, penetrations (around pipes, wires, vents) to maintain thermal continuity and avoid thermal bridging or air leakage.
- For roof or floor conversions, overlay appropriate boarding, flooring, or plasterboard over foam to provide usable surface while preserving insulation performance.
4. Quality Assurance, Safety & Compliance Checks
- Inspect for correct board thickness, coverage, and sealing at all seams and penetrations.
- Check that moisture control measures (vapour barrier, vents) are correctly implemented to prevent condensation or damp problems.
- Ensure structural fixings comply with building standards — especially when boards are used under floors or in load-bearing roofs/walls.
- Clean up installation debris, and provide ventilation/maintenance guidance for long-term performance.
Types of Rigid Foam Boards We Use
We tailor board selection to your building's needs, balancing performance, cost, and application. Common options include:
PIR (Polyisocyanurate) Boards
High thermal efficiency and thin-profile insulation — ideal when space is limited (e.g. between rafters or wall cavities).
XPS (Extruded Polystyrene) Boards
Strong, moisture-resistant, and suitable for floors, basement ceilings, or external ground-level walls where damp or moisture ingress is possible.
EPS (Expanded Polystyrene) Boards
A cost-effective option for internal walls or ceilings where extreme thermal performance is not critical but insulation, lightweight and ease-of-fitting matter.
For projects requiring external wall insulation or high moisture resistance, we recommend selecting boards with appropriate moisture-grade and finishing (render, cladding, boarding) as per building use and exposure.
When Rigid Foam Board Insulation Is Particularly Beneficial
Rigid foam insulation is especially advantageous in the following situations:
Benefits for Homeowners, Landlords & Property Managers
By choosing rigid foam board insulation through our service, you can expect:
FAQs — Rigid Foam Board Insulation
1.How thick should rigid foam insulation be to get good thermal performance?
It depends on your property type, climate, and thermal targets. Typically, boards of 50 mm to 100 mm thickness are used, but our survey and calculations will determine the ideal thickness based on U‑value requirements and building regulations.
2.Can I install rigid foam board myself, or should I hire professionals?
Due to structural, moisture‑control, and sealing requirements — and depending on project complexity (loft, roof, floor, moisture exposure) — professional installation is strongly recommended to ensure long-term performance, compliance, and safety.
3.Will foam board insulation prevent damp or condensation?
Yes — when combined with proper ventilation and vapour control (where needed). Closed-cell boards resist moisture ingress and, with correctly sealed joints and ventilation, help maintain a dry, stable building envelope that reduces condensation risk.
4.Is rigid foam board suitable for loft conversions where I intend to install flooring or a loft room?
Absolutely. Foam boards are both insulating and structurally stable, making them ideal under floorboards or roof decking. With proper fixings and sealing, you get a well-insulated, usable loft space with minimal heat loss.
5.How long does rigid foam board insulation last?
When installed correctly and kept dry, rigid foam board insulation retains its thermal properties for decades. It does not sag or settle over time, making it a durable, long-term solution.
Ready to Install Rigid Foam Board Insulation?
Get a free, no-obligation quote for professional rigid foam board insulation installation today.
Experience premium thermal performance and structural strength with our expert installation service.