Thermal Insulation & Moisture Control Specialists in London
We diagnose the cause of cold walls, condensation and recurring mould — then design the right system for your home. Survey-led, tidy installation, clear long-term results.
•London-wide • Fully insured • Typical response within 24 hours
• 20-year system guarantee.
• 20-year system guarantee.
Survey-led diagnosis (not guesswork)
Condensation & mould specialists
Moisture-safe insulation systems
Dust-controlled, tidy installation
Clear scope, stages & communication
How Sashtec Works
A clear process designed for lived-in London homes.
Take a look at our recent projects
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Victorian Flat — Greenwich, SE
Internal wall insulation with condensation control
Ground Floor Flat — Islington, N
Breathable insulation system installation.)
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Understand your home before choosing a solution.
Internal wall insulation in London flats: what really matters
Ventilation options explained: extractor, continuous, or MVHR
Condensation vs rising damp, how to tell the difference
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Services Overview
Internal Wall
Insulation
Insulation
Warmer rooms, improved comfort, and reduced condensation risk.
• Breathable systems for solid walls
• Designed for lived-in homes
• Measurable comfort improvement
• Breathable systems for solid walls
• Designed for lived-in homes
• Measurable comfort improvement
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Damp & Condensation Solutions
Accurate diagnosis followed by targeted, lasting repair.
• Identify true moisture source
• Prevent recurring mould
• Protect structure and finishes
• Identify true moisture source
• Prevent recurring mould
• Protect structure and finishes
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Healthy Home Ventilation
Continuous fresh air without unnecessary heat loss or noise.
• Humidity control year-round
• Quiet, efficient systems
• Healthier indoor air quality
• Humidity control year-round
• Quiet, efficient systems
• Healthier indoor air quality
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testimonials
What Clients Say
Feedback from homeowners and property managers across London.
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Astudio “Wellbeing Clinic” West London
“We had mould every winter. Sashtec’s survey uncovered the root cause, and now our home stays dry and warm — even in December.”
Sarah, Dulwich
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CrestHall “Property Management, NW London”
We are a property management company based in North West London with a portfolio across the whole of London. We have been using Sashtec since 2019 and are very happy with the level of service that we receive. The team enjoy working with their team and we would not hesitate to recommend.
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James, Hackney
“They didn’t just install insulation — they designed the right system for our old London terrace. Energy bills are noticeably lower.”
Aston Square “Homeowner, SE London”
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58 WellbeingCentre “Wellbeing Clinic” West London
“Professional from survey to installation. Clear explanations, no guesswork.”
Aisha, Greenwich
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If your enquiry is urgent, you may also call us directly.
If your enquiry is urgent, you may also call us directly.
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Tell Us About Your Property
The more detail you provide, the better we can understand your situation before arranging a visit.
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Phone & Whatsapp
+44 2035767535
Available during working hours.
If we are assisting clients on site, please leave a message and we will return your call as soon as possible
If we are assisting clients on site, please leave a message and we will return your call as soon as possible
Professional thermal insulation and damp prevention in London
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