The Role of Basement Tanking in Basement Conversion Projects

The Role of Basement Tanking in Basement Conversion Projects

8th September, 2023

Basement conversion projects have grown in popularity in recent years, and for good reason. As property owners seek to maximise their living spaces, basement conversions offer the perfect opportunity to do this without extending a property outwards. Converting a basement into a functional living area offers a huge number of benefits, from additional bedrooms and entertainment spaces to increasing the overall property value. However, these conversions come with their unique challenges, with damp being one of the most common concerns. This is why basement tanking can be highly effective, playing a crucial role in ensuring the success and longevity of a conversion. In this guide, we’ll be discussing everything you need to know about basement tanking – read on to find out more.

What is Basement Tanking?

Basement tanking, sometimes referred to as basement waterproofing, is the process of applying various materials, like a coating or membrane, to the interior or exterior of the basement, to prevent water from penetrating the space. It aims to create a barrier between the inside of the basement and the surrounding soil or groundwater, which not only prevents water ingress but also protects the structural integrity of the building and the overall quality of the indoor environment.

Basement tanking solutions can be broadly categorised into two main types: internal tanking and external tanking.

What is Internal Basement Tanking?

Internal tanking involves applying waterproofing materials to the interior surfaces of the basement walls and floors. This approach is commonly used when retrofitting existing basements, especially in older properties, due to the flexibilities available in the materials used – some of the most common materials used for the internal tanking process include:

Cementitious Coatings: These coatings are applied as a mixture of cement and additives that create a waterproof layer when applied to the surfaces. They are highly versatile and can be used on a range of substrates, including concrete and masonry, so they’re suitable for a whole host of different property types.
Cavity Drain Membranes: Cavity drain membranes consist of a studded plastic membrane that is fixed to the walls and floors. The studs create a gap between the membrane and the surface, allowing water to be channelled and managed effectively through drainage systems.
Waterproof Renders and Plasters: For a more specialised approach, renders and plasters are designed to create a waterproof layer that can be applied directly to the walls and floors.

What is the Difference Between Internal and External Tanking?

Basement tanking comes with several benefits that can not only protect your property but also improve your living space:

Preventing Water Damage: Water infiltration is a major concern in basement areas, primarily due to their location. Without effective basement tanking, water can seep through walls and floors, leading to issues like dampness and mould growth. These problems not only compromise the appearance of the space but also pose risks to the health of occupants and the structural integrity of the building.
Protecting Property Investment: A basement conversion project represents a significant investment in terms of time, money, and effort. Implementing proper basement tanking is essential to safeguard this investment, and by preventing water-related issues, you can ensure that your newly converted basement space remains functional and aesthetically appealing for years to come.
Enhancing Liveable Space: Basement conversions are often aimed at increasing the available living space within a property. Whether the basement is transformed into a cosy living room, a home office, or even an additional bedroom, the success of the conversion depends on creating a dry, comfortable environment. Basement tanking plays a pivotal role in achieving this goal, making the space habitable and enjoyable for occupants.
Compliance with Regulations: In the UK, there are many regulations that your basement conversion must meet, and these include adequate waterproofing measures that need to be carried out before the space can be classed as liveable. Using proper basement tanking methods will ensure that your project complies with these regulations, and help you avoid potential legal issues.

What Factors Should I Consider During a Basement Tanking Project?

Given the benefits of a basement conversion, it’s easy to overlook some of the crucial elements of a basement tanking project – here are four of the most important factors to consider:

1) Type of Tanking System: The choice between internal and external tanking depends on several factors, including the existing structure, site conditions, and budget. Internal tanking is often favoured for existing buildings due to its ease of application and minimal disruption to the property, while external tanking provides a comprehensive solution from the outside but requires excavation – which can be more complex and costly.
2) Type of Drainage System: An effective drainage system is an integral part of any basement tanking strategy. In internal tanking systems, cavity drain membranes direct water toward drainage channels, where it can be safely removed from the basement. External tanking systems also rely on proper drainage to prevent water accumulation against the external walls.
3) Professional Expertise: Basement tanking is a specialised process that requires a lot of knowledge and expertise. It’s always vital that you consult with experienced professionals like us to assess the specific needs of the project and recommend the most suitable tanking solution.
4) Maintenance Considerations: Regular maintenance is essential to ensure the longevity of basement tanking systems – While these systems are designed to provide long-term protection, periodic inspections and maintenance can address any potential issues before they escalate. Clearing drainage channels, checking for cracks, and addressing any signs of deterioration are important steps in preserving the tanking system.

Basement conversion projects offer a creative solution to space constraints and can significantly enhance the value and functionality of a property. However, the success of such projects hinges on addressing potential challenges like water ingress or rising damp. Basement tanking therefore plays a pivotal role in preventing water-related issues, protecting your investments, and ensuring the durability of the newly converted space. By seeking professional guidance, carefully considering the type of tanking system and committing to regular maintenance, you can confidently embark on a basement conversion project that stands the test of time.

Our Equipment

Damp Meter

Damp Meter

Purpose:

Takes comparative surface moisture readings across accessible walls, floors, ceilings and building joinery.

Common Uses / Notes:

Maps surface moisture profiles to help identify rising damp, penetrating damp, condensation, or active plumbing leaks.

Deep-Penetration Damp Meter

Deep-Penetration Damp Meter

Purpose:

Detects moisture changes deep below the immediate surface of structural materials without destruction.

Common Uses / Notes:

Evaluates dampness within wall cores, beneath floorboards, inside subfloors and behind finishes without removing plaster.

Non-Invasive Moisture Scanner

Non-Invasive Moisture Scanner

Purpose:

Scans surface planes non-invasively without inserting pins or probes into decorated finishes.

Common Uses / Notes:

Checks decorated walls, tiled surfaces and delicate floor coverings to trace sub-surface water migration non-destructively.

HD Borescope Inspection Camera

HD Borescope Inspection Camera

Purpose:

Provides high-definition visual examination inside enclosed, narrow, or inaccessible building cavities.

Common Uses / Notes:

Inspects subfloor voids, wall cavities, dry lining and enclosed pipework to locate leaks and defects with minimal disruption.

4K Inspection Drone

4K Inspection Drone

Purpose:

Captures high-resolution imagery and video of high-level external structures and rooflines.

Common Uses / Notes:

Inspects roof tiles, chimney stacks, lead flashing, parapet walls, valleys and gutters to locate water ingress sources.

Air Humidity Sensor

Air Humidity Sensor

Purpose:

Measures ambient air temperature and relative humidity (%RH) levels within living areas.

Common Uses / Notes:

Determines whether atmospheric moisture, cold bridging, or insufficient ventilation supports surface condensation and mould growth.

Thermal Imaging Camera

Thermal Imaging Camera

Purpose:

Visualises surface temperature differentials across walls, ceilings and floors.

Common Uses / Notes:

Detects cold spots, missing insulation, thermal bridges, evaporative cooling zones and concealed water leaks.

Airflow & Ventilation Detector

Airflow & Ventilation Detector

Purpose:

Measures volumetric air extraction performance (L/s or m3/h) of mechanical extractor fans.

Common Uses / Notes:

Tests kitchen, bathroom and utility fans to verify compliance with UK Building Regulations Part F and control condensation.

Gas Screening Instrument

Gas Screening Instrument

Purpose:

Screens indoor environments for sewer gas intrusion, combustible gases and combustion concerns.

Common Uses / Notes:

Traces foul odours, soil stack leaks and sewer gases (H2S, NH3, CH4, CO, O2). Does not replace Gas Safe registered safety checks.

Chemical Vapour Detector

Chemical Vapour Detector

Purpose:

Screens air for Volatile Organic Compounds (TVOC/VOC) and chemical substances like formaldehyde (HCHO).

Common Uses / Notes:

Investigates unexplained chemical odours, building material off-gassing, post-flood air safety and indoor air quality.

Airborne Particle Detector

Airborne Particle Detector

Purpose:

Measures airborne particulate concentrations across precise micron size ranges (PM1.0, PM2.5, PM10).

Common Uses / Notes:

Assesses fine dust, smoke, airborne matter and environmental air quality following water damage or mould outbreaks.

Electrical Socket & RCD Tester

Electrical Socket & RCD Tester

Purpose:

Provides basic safety and protective circuit screening in areas affected by dampness.

Common Uses / Notes:

Identifies socket wiring faults, tests RCD trip functions and checks AC voltage in wet areas. Does not replace an EICR.

Survey Levels & Package Specifications

Level 1

Standard Damp Survey

Standard price: £299 + VAT

Promotional Price: £199 + VAT (Limited Time Offer)

The Level 1 Damp Survey is a basic damp inspection designed to check the main accessible areas of the property for damp, leaks
and visible moisture-related issues.

Equipment provided

  • Damp meter

Inspection coverage

  • Inspection of walls
  • Inspection of floors
  • Inspection of ceilings
  • Leak inspection of drains and plumbing
  • Damp information and prevention guide

Who should choose Level 1?

This survey is best for customers who need a basic damp check where only a damp meter is used. It is most suitable for simple

damp concerns, such as suspected rising damp, visible damp patches, minor moisture concerns or a general check of accessible
areas.

The Level 1 Damp Survey is suitable where the customer wants a straightforward inspection of walls, floors, ceilings, drains and
plumbing without the use of advanced survey equipment.

Level 2

Detailed Damp & Timber Survey

Standard price: £399 + VAT

Promotional Price: £299 + VAT (Limited Time Offer)

The Level 2 Damp Survey includes everything in the Level 1 survey, with additional timber decay inspections and deeper
moisture testing.

Equipment provided

  • Damp meter
  • Deep-penetration damp meter for all building materials
  • Non-invasive moisture detection equipment

Inspection coverage

  • Inspection of walls
  • Inspection of floors
  • Inspection of ceilings
  • Leak inspection of drains and plumbing
  • Dry rot inspection
  • Wet rot inspection
  • Woodworm inspection
  • Deep moisture detection in building materials
  • Non-invasive moisture testing under floorboards and subfloors where accessible
  • Damp information and prevention guide

Who should choose Level 2?

This survey is best for customers who need a damp and timber inspection. It is suitable where there may be concerns about damp,

wood rot, dry rot, wet rot, woodworm or moisture hidden behind building materials.

The Level 2 Damp Survey uses equipment that can read deeper into building materials, including areas such as subfloors, under
floorboards, behind panelling and other accessible hidden areas. This allows us to get a better understanding of whether there may
be hidden damp within the property without dismantling or damaging materials.

This survey is very suitable for home buyers and sellers who want a more detailed damp inspection before purchasing or selling a
property.

Specialised Laboratory Diagnostic Add-Ons

Laboratory Analysis of Plaster Samples
Add-On 1

Laboratory Analysis of Plaster Samples

Price £299 + VAT

Small plaster samples are carefully taken from affected walls and submitted to an independent laboratory for salt analysis. The laboratory tests for the presence and precise concentration of hygroscopic salts, including nitrates and chlorides.

Diagnostic Value: Soluble ground salts are drawn up through masonry during rising damp and remain in plaster permanently. Salt analysis scientifically differentiates true rising damp from condensation or historic leak contamination.

Note: Plaster sampling requires minor material removal and is our only add-on involving minor invasive work.

Mould Laboratory Testing & qPCR DNA Analysis
Add-On 2

Mould Laboratory Testing & qPCR DNA Analysis

Price £299 + VAT

Surface swab or lift samples are submitted to an accredited laboratory for advanced qPCR DNA analysis.

Diagnostic Value: Accurately identifies exact mould species, measures contamination concentrations and detects hidden fungal growth inside cupboards or behind dry lining. Delivers impartial scientific evidence to guide safe environmental remediation.

Gases, Chemical Vapours & Airborne Particle Testing
Add-On 3

Gases, Chemical Vapours & Airborne Particle Testing

Price £299 + VAT

Comprehensive environmental air quality and gas screening tailored to specific property concerns.

Screening Suite Includes: IAQ air quality assessment, Volatile Organic Compounds (TVOC/VOC), Formaldehyde (HCHO), Particulate Matter (PM1.0, PM2.5, PM10), Sewer Gases (H2S, NH3, CH4), Combustion Gases (CO, O2) and ventilation performance.

Diagnostic Value: Air quality issues are often linked to damp, leaks and mould, but they cannot always be identified by a visual inspection alone. This testing helps detect hidden airborne contaminants, gases, chemical vapours and fine particles that may affect the property’s condition and indoor environment. It can also help identify problems such as poor ventilation, sewer gas ingress, off-gassing from building materials, combustion-related gases, or airborne particles following water damage, providing a more comprehensive understanding of the property’s condition.

It is also useful where a property has persistent unpleasant or unexplained odours. The testing can help investigate foul smells caused by damp, water damage, stagnant water, drains, sewer gases or chemical vapours, allowing the source of the odour to be identified more accurately.

Testing includes:

  • Indoor Air Quality Testing- IAQ
  • Volatile Organic Compound Testing- TVOC / VOC
  • Formaldehyde Testing- HCHO
  • Fine Particulate Matter Testing- PM1.0 / PM2.5 / PM10
  • Dust and Smoke Particle Testing- PM1.0 / PM2.5 / PM10
  • Sewer Gas Testing- H2S / NH3 / CH4
  • Gas Leak Screening- CH4 / C3H8
  • Carbon Monoxide Testing- CO
  • Hydrogen Sulfide Testing- H2S
  • Ammonia Odour
  • Testing- NH3
    Oxygen Level Testing- O2
  • Ventilation / Stale Air Assessment- IAQ / TVOC
  • Drain Smell Investigation- H₂S / NH3 / CH4
  • Chemical Odour Investigation- TVOC / VOC / HCHO / NH3
  • Post-Leak Air and Surface
  • Condition Assessment- PM2.5 / TVOC
  • Combustion Gas Safety Screening- CO / O2 / CH4
  • Building Material Off-Gassing Assessment- TVOC / HCHO
  • Airborne Pollutant Screening- PM1.0 / PM2.5 / PM10 / TVOC