Warm Roof Insulation Specialists
Warm Roof Insulation Lewisham
Insulation fitted along the rafters, on the roof slope — required whenever a loft becomes a habitable room. PIR/phenolic boards to current standards, correct ventilation gap, fixed price before we start.
- 100–150mm PIR/phenolic insulation to current standards
- 50mm ventilation gap maintained to prevent condensation and timber rot
- Free, no-obligation survey before any work begins
- Fixed price agreed before we start
- 12-month workmanship guarantee
Request a Free Loft Survey
We usually respond within one working day. No obligation.
🔒 No spam, no obligation. We usually get back to you within one working day.
100–150mm
33
£0
12mo
24/7
Fully Insured
Free No-Obligation Survey
Fixed-Price Quotations
12-Month Guarantee
Part of the Brilliant Group
London-Wide Coverage
Insulation on the Roof Slope, Not the Floor
Warm Roof Insulation is fitted along the rafters rather than the loft floor. Unlike simple Loft Insulation, it’s required whenever a loft becomes a habitable room — the loft itself becomes part of the heated house, so the insulation has to move from the floor to the roof slope.
Required for Habitable Lofts
Whenever a loft becomes a bedroom, office or living space, building regulations require insulation along the rafters, not just the floor.
50mm Ventilation Gap
A maintained gap between insulation and roof covering lets moisture escape, preventing condensation and rot in the roof timbers.
PIR or Phenolic Boards
Higher-performance insulation than mineral wool, needed because rafter depth is more limited than loft floor space.
Usually No Need to Remove Tiles
In most cases warm roof insulation is fitted from inside, without touching the roof covering, unless a full re-roof is happening anyway.
Not the Same as Loft Insulation
If your loft is staying a storage space, not a room, Loft Insulation is what you need instead.
Fully Insured, Every Job
Public liability insurance covers every survey and installation we carry out.
Warm Roof Insulation Prices
Cost depends on your loft’s size, roof pitch and whether insulation is being fitted as part of a wider conversion. A free survey confirms the exact fixed price.
Warm Roof Insulation (per m²)
PIR/phenolic board insulation along the rafters
Insulation + Ventilation Upgrade
Insulation fitted alongside a proper ventilation gap
Pre-Conversion Survey
Full assessment before a Velux or room conversion
£0
Insulation for Existing Conversion
Retrofitting insulation into an already-converted loft
Our fixed price policy:
The price agreed after your free survey is the price on your invoice. No call-out charge, no surprise extras.
What Makes Us Different
Warm Roof Insulation is fitted along the rafters rather than the loft floor. Unlike simple Loft Insulation, it’s required whenever a loft becomes a habitable room — the loft itself becomes part of the heated house, so the insulation has to move from the floor to the roof slope.
Correct Diagnosis First
Loft Insulation and Warm Roof Insulation solve different problems. We diagnose which one your loft actually needs before recommending any work.
Fixed Prices & Free Survey
Every job starts with a free, no-obligation loft survey. Once we've assessed the work, you receive a fixed price — agreed before we start.
Fully Insured, Every Job
Every loft job — whether a single insulation top-up or a full conversion — is covered by our public liability insurance from the moment our installer arrives.
Local Borough Knowledge
From typical joist spacing to common roof constructions in your area, our installers know the loft types found across London's boroughs.
Part of the Brilliant Group
The loft division of the same team behind Brilliant Plumbing and Brilliant Roofing Group's London operations — same standards, applied to a new trade.
12-Month Guarantee
Every loft job comes with a 12-month workmanship guarantee. If any work we've completed develops a fault, we return and fix it at no charge.
The Process
How to Book a Loft Service in London
Four simple steps from your first call to a fully guaranteed job.
Call or Request Online
Call our team or fill in the form above. Tell us your borough, roughly what you need, and your contact details. Takes under 2 minutes, no commitment.
Free Loft Survey
We arrange a free, no-obligation survey at your property. Your surveyor inspects the loft in full and explains exactly what it needs.
Fixed Quote You Approve
Based on the survey, we give you a fixed price. No pressure, no hidden extras. Work won't start until you approve it.
Installed & Guaranteed
Work completed to a high standard. Your home left clean and tidy. 12-month guarantee certificate emailed the same day.
Customer Reviews
What London Homeowners Say
We’re a new business, so there’s no review history to show yet. The three cards below are sample placeholders, illustrating how real, verified reviews will display once we’ve collected them.
mt
Michael T.
Lewisham · Warm Roof Insulation
“Explained why our conversion needed insulation along the rafters, not just on the floor. The price stayed as quoted.”
Verified
ab
Aisha B.
Lewisham · Ventilation Gap
“The ventilation gap was properly explained. Another company hadn’t even mentioned it.”
Verified
cw
Chris W.
Lewisham · Pre-Conversion Insulation
“PIR boards were fitted before our Velux work started. Everything was well coordinated.”
Verified
Frequently Asked Questions
All Your Most Common Questions Answered
Loft Insulation is laid flat on the loft floor, for lofts that stay unused storage space. Warm Roof Insulation is fitted along the rafters, required whenever the loft becomes a habitable room, such as with a Velux conversion. They solve different problems and aren't interchangeable.
Yes, essentially always. Building regulations require insulation along the rafters whenever a loft becomes a habitable room, unlike simple loft insulation which only applies to unused storage space.
Roughly 100–150mm of PIR or phenolic board is the current standard for warm roof insulation, compared to 270mm of mineral wool for loft floor insulation — PIR/phenolic performs better per millimetre, which matters where rafter depth is limited.
Without a maintained airflow gap between the insulation and the roof covering, moisture can become trapped and cause condensation, leading to timber rot over time. We always maintain this gap as standard.
Usually yes — warm roof insulation is normally fitted from inside the loft. Removing tiles is only needed if you're having a full re-roof at the same time.
Yes. Every warm roof insulation job comes with a 12-month workmanship guarantee.
Service Areas
Loft Specialists in Your Borough
London’s loft spaces vary hugely — from small Victorian terrace lofts to larger post-war semis and new-build roof voids. Local experience matters. Our teams know the roof types common in your borough.
Get Started
Ready for Warm Roof Insulation in Lewisham?
A free survey removes the risk — you know the exact cost before we touch your loft. Fixed prices, available across all 33 London boroughs.
DW
David W.
★★★★★
Every job starts with a free survey — we assess your loft, explain what it actually needs, and you decide whether to proceed. No pressure, no obligation.
Free, No-Obligation Survey
SM
Stephanie M.
★★★★★
Every loft job comes with a written 12-month workmanship guarantee. If anything we’ve done develops a fault, we return and fix it at no charge.