InsulationMatch project library

Insulation projects, explained properly.

Every property is different. Roof construction, existing insulation, available space, ventilation, moisture and how the homeowner intends to use the loft can all change the most appropriate solution. Our project library is designed to show how different insulation challenges are assessed and which questions should be answered before work starts. As completed InsulationMatch projects are documented, they are added to this library with genuine project information and installation imagery.

Check my home Explore project types

About our project library

Completed projects are only presented as case studies when we hold sufficient genuine project information to support them. Until then, the project scenarios below demonstrate common property situations and the assessment process we would expect to consider. They are not presented as completed customer installations.

Real InsulationMatch projects

Documented projects are added here as they complete: location, month, property, survey findings, options considered, system chosen and why, installation photographs and installer observations. Town or postcode district only — never a full address.

Every project is written up to the installation standard: before, during and after photographs; product and certificate; ventilation route; completion records.

Typical project scenarios

Educational scenarios, not customer case studies. Each one shows the questions a survey has to answer and the routes that may come out of it.

Typical project scenario 01

Cold loft with limited rafter depth

Typical detached or semi-detached home

Homeowner objective

Improve thermal performance while retaining usable loft space.

What should be assessed

existing loft-floor insulation
rafter depth
roof membrane
ventilation
moisture
services
loft usage

Solutions that may be considered

MultifoilThin, continuous, certified with air gaps

PIRFixed depth, single certificate

Mineral woolCheapest on the loft floor

Combined build-upMultifoil under, PIR between

Multifoil systems can be attractive where available construction depth is limited, but suitability depends on the complete build-up rather than material thickness alone.

What could change the recommendation

Rafters under 100mm push the layer under the rafters
Damp timbers stop everything until the cause is found
An unused loft usually points back to the loft floor

Check my loft Thickness guide · Under-rafter detail

Typical project scenario 02

Foil insulation beneath roof rafters

Roof-level insulation upgrade

Homeowner objective

Improve roof-level insulation without losing headroom.

What should be assessed

is the loft heated or unheated?
is the roof breathable?
what ventilation exists?
what air gaps are required?
what thermal target must the complete construction achieve?
is the space being converted?

Solutions that may be considered

MultifoilMay form part of an appropriate roof build-up

PIRWhere a fixed-depth single product suits

Mineral woolWhere depth is not constrained

HybridMultifoil plus PIR to reach the target

Multifoil may form part of an appropriate roof build-up. Other projects are better suited to PIR, mineral wool or a hybrid system.

What could change the recommendation

A non-breathable felt needs a 50mm ventilated gap
A target U-value usually brings PIR into the build-up
Conversion adds fire and building control requirements

Check my roof Air gap guide · U-value guide

Typical project scenario 03

Loft storage without losing insulation performance

Boarded or soon-to-be-boarded loft

Homeowner objective

Retain loft storage while improving insulation.

What should be assessed

existing insulation depth
loft boarding
joist depth
headroom
roof construction
intended storage area

Solutions that may be considered

Raised loft boardingFull 270mm wool stays uncompressed

Improved floor-level insulationTop up under the boards

Rafter-level insulationIf the whole loft is to be usable

Combined approachFloor plus a foil layer over

Boarding straight onto 100mm of wool crushes it. Raised boarding or a rafter-level route keeps the performance.

What could change the recommendation

Low joists make raised legs the only floor option
A need for a warm, usable loft moves the insulation to the rafters
Water tanks and services set where boards can go

Explore loft insulation Loft boarding guide · Foil for lofts

Typical project scenario 04

Room-in-roof insulation upgrade

Existing attic room colder than the rest of the house

Homeowner objective

Bring an attic room up to the comfort of the rooms below.

What should be assessed

slopes
stud walls
residual voids
ceilings
ventilation
existing insulation
moisture
accessibility

Solutions that may be considered

Multifoil to slopes and studsOne continuous layer

PIRWhere slopes are opened up

HybridMultifoil under, PIR between

Void treatmentInsulating the residual voids properly

A room-in-roof project may involve more than one insulation product or installation method.

What could change the recommendation

Whether the room is stripped back decides what is reachable
Dwarf-wall voids need their own ventilation path
Existing plasterboard fire class affects the finish

Check my room-in-roof Room-in-roof guide · Foil roof insulation

Typical project scenario 05

Spray foam removed — what comes next?

Replacement insulation after foam removal

Homeowner objective

Replace removed spray foam with a sound, mortgage-friendly build-up.

What should be assessed

roof timbers
membrane
remaining foam
roof condition
ventilation
intended use

Solutions that may be considered

Mineral woolLoft floor, where the loft is unheated

PIRBetween rafters with a ventilated gap

MultifoilUnder rafters for a warm roof

Hybrid constructionWhere a target must be met

Nothing goes back in until the timbers, membrane and ventilation have been checked and recorded.

What could change the recommendation

Residual foam on the membrane changes the ventilation design
Timber moisture readings decide the timeline
A lender letter may need a specific build-up

Explore spray foam replacement Spray foam removal · After removal

Typical project scenario 06

When foil may not be the right answer

Homeowner asks specifically for foil insulation

Homeowner objective

Answer the question the property asks, not the one that was searched.

What should be assessed

is the loft accessible and unheated?
is the ceiling level the right place to insulate?
what is there now, and how deep?
is anything stopping a straightforward top-up?

Solutions that may be considered

Traditional loft rollSimpler, cheaper, does the same job on a loft floor

Foil over joistsOnly if boarding forces a thin layer

Rafter-level foilOnly if the loft is to become a warm space

InsulationMatch should not recommend foil simply because the homeowner searched for foil. The objective is right property, right build-up, right insulation.

What could change the recommendation

A plan to convert the loft flips the answer to the rafters
Storage boarding brings a thin foil layer into play
Nothing else does — the loft floor wins

Find my insulation match Multifoil vs mineral wool · Loft insulation guide

Which scenario is your home?

Two minutes. See the likely route and what should be assessed first, before any contact details.

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