Business Details
50+ Years
experience
Trusted Roofing Solutions in London
Established in 1963, Guaranteed Asphalt has evolved from a specialist mastic asphalt provider to the UK's leading manufacturer and installer of comprehensive roofing solutions. Our expertise spans mastic asphalt, hot melt systems, built-up felt, living roofs, single-ply membranes, and liquid coatings, developed through five decades of adapting to industry advancements. As a trusted partner in public and private sector projects, we combine technical innovation with cost-effective delivery, maintaining rigorous quality standards through accreditations like BBA certification and Safe Contractor status. Our team's deep understanding of modern construction challenges ensures tailored waterproofing solutions for diverse architectural requirements across London and nationwide. 
Services
Mastic Asphalt
Hot Melt Systems
Built-Up Felt
Living Roofs
Single-Ply Membranes
Liquid Coatings
Details
- Year established: 1963
Highlights and features
- We have over 60 years of specialist roofing experience since 1963
- UK's sole manufacturer and installer of mastic asphalt systems
- Offer 6 technical roofing solutions including living roofs and liquid coatings
- BBA-certified systems for guaranteed performance standards
- Proven expertise in cost-sensitive public sector contracts
Associations and certifications
- Safe Contractor
- Construction Line
- Made in Britain
- Achilles CHAS
- BBA
Services
Mastic Asphalt
Our proprietary mastic asphalt systems provide durable, seamless waterproofing for flat roofs. Formulated for thermal stability and chemical resistance, these systems suit commercial buildings and infrastructure projects. BBA-certified installations come with 20-year performance guarantees.
Hot Melt Systems
GuaraTEC hot melt membranes create fully bonded waterproof layers ideal for inverted roofs and podium decks. The solvent-free application process ensures environmental compliance while achieving Class 0 fire ratings on approved substrates.
Living Roofs
GuaraGREEN living roof systems combine waterproofing with biodiversity enhancement. Our solutions include lightweight substrates, drainage layers, and drought-resistant vegetation for sustainable urban developments and LEED-certified projects.
Liquid Coatings
Cold-applied liquid coatings form seamless waterproof barriers suitable for complex geometries. These rapid-curing systems allow immediate foot traffic and integrate with insulation layers for energy-efficient roof constructions.
Single-Ply Membranes
We install high-performance single-ply membranes like EPDM and TPO, offering excellent UV resistance and thermal movement accommodation. Mechanical fixing and ballasted systems available for industrial and commercial buildings.
People
David Boyd
Designer
Specialising in technical roof design with 15 years' experience in BIM integration and NBS specification writing for complex architectural projects.
Garo Susmanyan
Senior Designer
Senior roofing designer with expertise in heritage building restoration and sustainable waterproofing solutions for listed structures.
Henri Taylor
Estimating Director
Lead estimator with 20 years' experience in cost analysis for public sector contracts, specialising in value engineering for tight-budget projects.
Questions
What roofing systems does Guaranteed Asphalt offer?
We provide six technical solutions: mastic asphalt, hot melt membranes, built-up felt, living roofs, single-ply membranes, and liquid applied coatings for flat and sloped roofs.
Are you certified for public sector contracts?
Yes, we hold Safe Contractor, Construction Line, and Achilles CHAS accreditations, meeting all requirements for UK government construction projects.
Do you handle heritage building projects?
Our expertise includes historic structures like 20 Old Bailey and Aberfeldy Village, combining traditional techniques with modern waterproofing technology.
What makes your asphalt systems unique?
As the UK's sole manufacturer/installer, we control quality from production to application, offering guaranteed performance with BBA-certified systems.
Can you provide technical documentation?
Yes, we supply full NBS specifications, BIM models, and technical data sheets for all systems through our online resource portal.
