1 · Survey the detail

Engineer assesses the specific thermal-bridge condition — reveal width, lintel depth, balcony connector geometry, services route diameter. For EWI scopes, the reveals are surveyed as part of the EWI design; the aerogel scope is sized alongside the main board scope. For services routes, the duct or pipe diameter and length are recorded for blanket cut-to-fit.

2 · Cut to size on site

Blanket cut with a craft knife or sharp scissors. Straight cuts for reveal strips and lintel wraps; shaped cuts for door thresholds and services penetrations. Cutting releases minor aerogel dust — installer wears a dust mask and uses a vacuum to collect debris. The non-woven fibre carrier holds the aerogel in place; cut edges don't fray.

3 · Adhered with Proctor adhesive

Spacetherm Adhesive applied to the substrate; the aerogel blanket pressed in. For curved applications (services wraps), the blanket is bonded along its length and self-tensions around the wrap. For straight applications (reveals, lintels), the blanket is bonded edge-to-edge with subsequent pieces taped at joints for continuous coverage.

4 · Joint tape (if needed)

For continuous coverage across multiple blanket pieces, joints are taped with self-adhesive aluminium tape or Proctor-specified joint tape. The thermal continuity matters — gaps between blanket pieces are thermal-bridge weak points. For reveal applications, the perimeter is also taped to the wall above and the window frame to prevent air leakage past the blanket.

5 · Finish layer

The blanket accepts plaster direct in IWI applications (skim coat over Proctor's specified base coat). In EWI reveal applications, the blanket is covered with reveal-grade reinforcing mesh and base coat to match the main EWI render system. In services wrap applications, the blanket is left visible or covered with light cladding depending on the project's aesthetic requirement.

6 · Thermal verification

For PHI-target and EnerPHit projects, the thermal-bridge ψ-value at every detail location is calculated post-install with Therm or PHPP. The aerogel correction typically drops the local ψ-value by 50–70% on reveal junctions and balcony connectors. CleverBloom coordinates with the Certified Passivhaus Designer on detail confirmation.

Silica aerogel

Aerogel is a nano-porous silica structure that is 90%+ air by volume. The pores are smaller than the mean free path of air molecules at room temperature, which means air can't convect inside the structure — heat conducts only by the silica matrix and by radiation, both of which are slow. The result is the lowest thermal conductivity of any solid insulation material in standard commercial supply.

Non-woven fibre carrier

The aerogel is impregnated into a non-woven polyester or glass-fibre carrier matrix that provides the structural backbone. Without the carrier, aerogel would be a fragile powder; with it, the blanket is textile-like and can be handled, cut, rolled, and installed without specialist tools. The carrier contributes negligible thermal load — λ is dominated by the aerogel.

Aspen Aerogels chemistry

Manufactured by Aspen Aerogels (Northborough, Massachusetts, US) under the Spaceloft brand. The technology was originally developed for NASA spacecraft insulation in the 1990s and commercialised by Aspen Aerogels in 2003. UK supply via A. Proctor Group (Stirling, Scotland) under the Spacetherm brand line; the company is one of Aspen's primary European distributors.

Hydrophobic silica matrix

The silica surface is treated to be hydrophobic during manufacture. Water sits on the blanket and runs off without absorbing. The blanket can be exposed to incidental water (driving rain during install, condensation on adjacent pipework) without degradation; the λ value is unchanged after water exposure and subsequent drying.

Fire: Class C

Spacetherm Aerogel Blanket tests Euroclass C — better than Class E wood fibre, worse than Class A1 mineral wool. The Class C rating is sufficient for concealed applications (behind plasterboard, in stud cavities, wrapped around services in voids) under Approved Document B. For exposed applications or buildings over 11 m external wall height, the Spacetherm A1 variant offers Euroclass A1 with slightly higher λ.

Vapour-permeable

Water vapour resistance factor μ < 5 — the blanket is highly vapour-permeable. Moisture passes through without trapping; the assembly behind stays self-drying. This is why aerogel works in heritage retrofit and breathable build-ups where vapour-tight materials would cause interstitial condensation.

50+ year design life

Aspen Aerogels publishes a 50+ year design life for Spaceloft chemistry in standard service. The silica matrix is chemically stable; the hydrophobic treatment doesn't wash out. Once installed and finished, the blanket performs for the life of the building.

No annual service required

No moving part, no electrical component, no consumable. Behind plaster or render, the aerogel is entombed for the life of the building. Visible applications (some services wraps) are inspected on the homeowner's normal maintenance cycle.

Doesn't degrade with water exposure

Hydrophobic chemistry means water exposure (driving rain during install, condensation on adjacent surfaces) doesn't compromise λ. The blanket dries out and continues performing. This is what makes it suitable for reveal and threshold applications where water tracking is part of normal service.

Joint discipline at install

The aerogel only delivers its λ if the joints between blanket pieces are tightly butted and taped. A 5 mm gap between adjacent reveal strips creates a localised thermal bridge that undermines the whole detail. CleverBloom installers tape every joint as standard — non-negotiable on PHI-target scopes.

Future trade penetration discipline

After install, every new electrical or plumbing service that penetrates the aerogel layer (services routed through a wrapped reveal, cables run through a lintel) compromises the thermal performance unless re-sealed. CleverBloom provides offcut blanket and adhesive to the homeowner as part of the handover pack — same principle as the Pro Clima Roflex grommet handover.

EWI scope alignment

Aerogel reveal correction is only as good as the main EWI scope it sits inside. If the EWI is missing or under-specified, fixing the reveals alone won't deliver Part L 2022 wall U-values. CleverBloom only quotes aerogel reveal correction as part of a coordinated EWI scope (Gutex Thermowall or STO Therm Mineral K) — not as standalone "we'll just do the reveals".