Survey Glossary


Aggregate is a combination of stone, sand and gravel that is often used for creating concrete in the building industry. Builders use Aggregate to fill in spaces by attaching it with cement, which makes the concrete or bitumen....

Air Brick

An Air Brick contains holes or perforations to permit the flow of air through a wall.


Amosite is considered an extremely hazardous form of asbestos - surveyors look out for ceiling tiles containing asbestos.  Prolonged exposure to Amosite carries a significant risk of developing asbestosis.


An Architrave is commonly defined as a door surround although it is truly described as a moulding that surrounds any rectangular opening. It can consist of a number of materials, including white board and, most often, timber.


Artex may be out of fashion and hard to remove, but if it was put up more than 30 years ago it may contain asbestos.


Between 1950 and 1980 asbestos was used extensively in the booming construction of post-war Britain. If the fibres are breathed in high concentrations for a period of time, they can cause serious illness and even death.


Asbestosis is a chronic condition caused by inhalation of asbestos fibres – usually over an extended period. 

Attic Conversion

For information about Attic Conversions, please see Loft Conversion....

Balanced Flue

A Balanced Flue is a superior heating device developed in Holland in the 1930's. Whereas traditional heating appliances were 'open' (i.e. they drew air from inside the house to create a fire, then released excess gases through the chimney to outdoors), heating appliances installed with a Balanced...

Ball Valve

A Ball Valve is the device that prevents water from flowing into the toilet and controls the flow of water into a toilet when it is flushed. It is called a Ball Valve because it is a Valve with a hollowed spherical disc at its centre.


A Baluster is commonly found on a staircase - they are the spindled, often wooden, forms that support the handrail going up the stairs.


A Bargeboard (sometimes referred to as a 'Vergeboard') is a wooden or PVC board that fitted to the gable ends of the roof of a property.

Battens (roofing)

A Batten is a strip, usually consisting of wood, plastic or metal, which is used to fix roof tiles or a roofing sheet into place. 

Bituminous Felt

Bituminous Felt is used to waterproof flat roofs. Roofs of this kind are prone to absorb water because they do not have the natural run-off that is provided by their sloped counterparts. Bituminous Felt is made up of a mixture of substances, including: Bitumen - (also called asphalt) - a...


A Bressummer, generally found in older buildings, is a large timber beam. It is used as part of a supporting structure to the outside of a building or its middle floors. A Bressummer lies horizontally and performs the function of load-bearing. Further beams can be fitted into it to create a timber...

Building Conservation

Building Conservation describes efforts to preserve the substance and style of a building over time. The notion of ‘preservation’ is key to understanding Building Conservation, which aims to preserve, or maintain, the original features of a building. For example: If the stone walls...

Buildmark Cover

Buildmark Cover protects owners of new homes against defective building practices. It does not, however, guard a buyer against the poor maintenance of previous owners.

Calcium Chloride

Calcium Chloride was a cement additive used to reduce the 'setting' or 'hardening' time of the cement. Over time, Calcium Chloride has become problematic as it is water absorbent, reacts with water and produces a corrosive agent that attacks steel.

Cavity Wall

A Cavity wall is made of 2 distinct or separate walls with a gap or 'cavity' between them.  The gap is typically around 10cm.

Cavity Wall Insulation

In order to keep your energy costs down, you may consider Cavity Wall Insulation. This is the installation of an insulating material in the air space of a Cavity Wall. Materials used include: Glass fibre Rock Wool Wool As a Cavity Wall Installation leads to greater energy...

Cavity Wall Tie Failure

Cavity wall tie failure is a common problem in Home Buyers Surveys in England and Wales. Find out more about how to safeguard against this potentially expensive problem.

Ceiling Joist

Ceiling Joists are used in conjunction with beams to support the ceiling construction.

Cement Weathering

Cement Weathering is used to prevent water seeping through the join of a chimney stack and roof. In this sense, it serves the same purpose as chimney flashing. A narrow band of cement is applied to the base of a chimney stack where it meets the roof covering. Cement Weathering is more commonly...


Condensation is the process whereby water vapour changes into water droplets. It is an important concept for building surveys because it can lead to damp. If there is water vapour within a building, it may condense into liquid water. This is more likely to happen on cold surfaces such...

Corrugated Iron Roofing

Corrugated Iron is used as a roofing material and is typically found on sheds, barns, out-buildings and ‘lean to’

Damp-Proof Course (DPC)

A Damp-Proof Course protects walls from 'rising damp', or moisture rising up from building foundations.

Damp-Proof Membrane (DPM)

A Damp-Proof Membrane is a barrier used to protect a solid floor from moisture, or 'rising damp'.


Daylighting is a broad term used to describe the implementation of windows or other transparent surfaces that allow natural light into a building. The purpose of Daylighting is to provide natural lighting in rooms, reducing our dependence on electrical lighting. What are the benefits of...


A Defect is any non-conformity with standard or shortfall in performance of an element of a property. It is synonymous with ‘fault’. The main focus of Home Buyers Surveys is to uncover any Defects within a property. There are as many possible kinds of Defect as the imagination will...

Design Life

 The Design Life of a building or part of a building is the length of time that it is intended to fulfil its function, or work properly. The Design Life of, say, a window is the designer’s opinion of how long the window will maintain its optimal condition. Evaluating the Design Life of...

Dilapidations Survey

A Dilapidations Survey is a survey undertaken to assess the condition of a property, specifically any damage, or dilapidation, that has occurred to it. A Dilapidations Survey is thorough and will list defects as grave as structural faults in a building and as minute as stained surfaces....


A Dormer is any structure that juts out from a sloping roof. Think of windows you have seen that are built on a sloping roof –not skylights, which are positioned on the roof itself but windows that are positioned on the face of a structure built out of the sloping roof. That structure is a...

Double Glazing

Double Glazing describes windows that consist of two sheets of glass (triple glazing describes windows that consist of three sheets of glass).  The purpose of Double Glazing is to insulate a building better. A great amount of heat is lost through window space as windows are thinner than walls....


A Downpipe, or drainpipe, carries rainwater from the roof gutter to the ground or to a drain.

Drainage Survey

A Drainage Survey is a full investigation of the drains serving a property.  Fridaysmove's panel of surveyors use the very latest keyhole camera technology as part of the process....

Dry Rot

Dry Rot is the least common variety of wood rot fungus. It is also the most destructive as it destroys the very cells of wood, reducing it, eventually, to a crumbly substance. Unlike wet rot, Dry Rot can occur in the absence of damp timber - for this reason, poorly ventilated areas are of...


Durability refers to the ability of a building, or part of a building, to perform its intended function over time and in the face of deteriorating elements. Unlike design life, Durability is not an inherent property of a building or its components. (E. g. the same window will possess different...


'Eaves' is the term used to describe the low edge of a roof that protrudes beyond the property's walls.

Economic Life

The Economic Life of a property is, simply, the period of time it is expected to be worth anything. At the end of its Economic Life, a building is no longer valuable as an asset, although the land that it sits on should still be. The physical life of a property is a longer affair. Think about it: a...

Electrical Installation Condition Report (EICR)

Electrical Installation Condition Report  or 'EICR' is a full report on the mains wiring and associated systems in a residential or commercial property.


A house Extension occurs when a building which serves as a home is extended: this can involve building a new room (or rooms) or by making existing rooms larger. Although Extensions can be performed by home owners themselves, it is not advised that you do so unless you have experience in...

Eyebrow Window

An Eyebrow Window is a window positioned on an Eyebrow Dormer. Here we use ‘Eyebrow Window’ to refer to the whole structure, as is often convention, although technically inaccurate.  An Eyebrow Window is positioned on a sloping roof. Like all dormers, it is a structure that...


The term Fascia describes any horizontal surface spanning the top of a wall. A 'fascia board' caps the end of external rafters, with the soffit, or eaves, located below.


Flashing is a building method used to prevent leakage at a roof joint.   Flashing is used around objects that protrude from the roof of the property e.g. parapet walls, chimneys etc in order to direct water away from the join. Materials typically used for Flashing are metal (lead...

Flat Roof

A Flat Roof is seemingly self explanatory insofar as it is a roof that is not pitched or sloping.  In fact a Flat Roof is not completely flat as a slight incline is required for rainwater to run off into the guttering.


Flaunching describes the mortar filler around the base of a chimney pot. This mortar acts to hold the pots in place, and prevents the entry of water into the stack.

Floor Joists

Floor Joists are horizontal elements running between walls to support the floor. They are commonly constructed from wood, steel or concrete.

Floors (solid and suspended flooring)

There are, broadly, two common types of Flooring:suspended Floors, and solid FloorsA suspended Floor is a specialist construction made of a solid concrete Floor, a system of sleeper walls and timber joists, upon which sits a supported timber floor. This type of floor allows home...

Foul Drain

Foul Drains dispose of waste water from toilets and sinks into a public sewer.


Foundations form the structural base upon which building structures sit.  Typically Foundations consist of concrete trenches or slabs set below the ground to form a structural standing base for a wall: Foundations may be made of brick or stone in historic or older...

Gable End Wall

The commonly triangular-topped end wall which is parallel to the trusses, and which extends vertically to the rafters of a property.


A Garret describes any loft space that has been made habitable – regardless of how cramped it is. Garrets are most liveable underneath Mansard roofs.

Green Building

A Green Building (or Sustainable Building) is a building that is designed (or renovated) with consideration towards its impact on the environment. Each year, more and more Green Buildings are built. Some ways in which a Green Building may help the environment are: Energy Efficiency –...

Ground Heave

The term Ground Heave is used by Building Surveyors to denote an swelling of the soil beneath a structure. It is essentially the opposite of subsidence, however it has its own unique causes and solutions.


A Gulley is the ground-level point between the Downpipe and drain, where excess rainwater is discharged away from the property.


A rain Gutter is the narrow trough or channel which surrounds the roof of a house, designed to collect and direct rainwater off the roof.

HIP Roof

A Hip Roof, unlike a standard pitched roof with gable ends, has no vertical sides.  Instead a Hip Roof resembles a pyramid structure where all sides of the roof are pitched or on an incline....

HIP Tile

A 'Hip Tile' is an angular tile that is used to cover over the intersection of roof tiles which meet at the external junction between intersecting pitched roof slopes....

House Longhorn beetle

The House Longhorn beetle (Hylotrupes bajulus) is a wood-boring beetle known for its voracious appetite for softwood timbers and the significant damage it causes, generally to older homes.

Inspection Chamber

An Inspection Chamber provides access to sewers or storm drains, so that maintenance or inspection of the surrounding drain network can be undertaken.


Ivy is notorious for causing damage to brickwork and wood. Its powerful roots (the very source of its climbing aptitude) drive into mortar and between timbers causing damp penetration and structural weakening.

Knotweed (Japanese Knotweed)

Knotweed can cause both structural and environmental damage, and may be expensive to treat successfully.

Lead Roofing

Lead was used extensively used in the past and is still maintained on older buildings to preserve the original character.  Lead can be problematic however as this article reveals.


Loam is a good foundation for a home. However there are common problems that can be avoided if regular maintenance practices are employed.

Loft Conversion

A Loft Conversion is carried out when the Loft or attic space of a building is converted into additional living space.  Increasingly, Loft Conversions are being seen as the best way to get the most out of a home. Home owners are thinking 'Why move out, when we can move up?' Why a Loft...

Mansard Roof

A Mansard Roof is an attractive and unique kind of roof that was popular in the late 1800's. It consists of two parts: a lower, near-vertical section that is adjoined to a higher, near horizontal, section.


Masonry describes two, closely related, entities: Structures formed by collections of single units that are bound together by mortar, i.e. a brick wall (hundreds or thousands of individual bricks 'stuck' into one solid wall by the application of mortar). The single units themselves are also...

Mastic Sealant

Mastic Sealant is an adhesive typically applied to window and door frames, bathroom fittings, and cracks in walls. Mastic Sealant is widely used because it has the following properties: It sticks to nearly every material It is water-proof It retains its form in low and high...


Mortar is the paste used to bind blocks of masonry together, forming structures such as walls.  It is a mixture of cement, sand, and water. Although mixtures vary, roughly 1 part cement is added to 3 parts sand and then water is added until it becomes a paste. The paste is applied to the...

Nail Sickness

Nail Sickness occurs when the nails that secure roof tiles or slates on a sloping roof deteriorate and, subsequently, tiles or slates become loose and may even slip off.  The malady is particularly common in older buildings where fixer-nails were produced with only mild steel that is more...


Obsolescence, in regards to property, describes out-of-datedness in a building or features of a building. Now this must be broadly understood: if a home, or some part of it, presents any kind of problem as a result of its construction not meeting modern demands, then this may be said to be Property...

Overflow Pipe

An Overflow Pipe is so called because it is a Pipe that is fitted to a liquid container to prevent Overflow. It is positioned above a desired maximum liquid level so that, should liquid breach this height, it will be channelled through the Pipe, unable to rise any further. In homes, Overflow Pipes...


A Parapet is also the term used to describe low walls around roofs and flat roof terraces.  Parapet is also the correct word for similar low wall barriers used in castles, fortified structures, churches and  cathedrals.

Partition Walls

A Partition Wall is simply any wall of a house that separates rooms - it does not separate the inside of a building from the outside. It is unlikely to be a load-bearing wall. It can be constructed using a number of materials...

Party Wall

If a residence shares a wall with an adjoining property, that wall is referred to as a party wall. The Party Wall etc Act 1996 defines the procedures to observe when a dispute arises.

Pebble Dashing

Pebble Dash is a special kind of render. Whereas common render is applied to the outside of a house with a view to providing a smooth finish, Pebble Dashing aims to create a finish that has a rough or 'pebbled' effect. This is often achieved by including pebbles or shells in the Pebbledash mix, or...

Penetrating Damp

Our homes are in a constant war of attrition with the elements to keep us warm and dry. If they don't get reinforcements, penetrating damp can occur.

Planning Condition

This is a condition attached to a planning permission grant. A planning condition limits the extent to which planning permission can be utilised at a property. Many local councils have either removed or restricted homeowners' rights to develop their properties.  Buyers are strongly encouraged...


A Pot is a clay lining of a chimney.   pots will usually be commented on in a Home Buyers Survey.  For example if the fireplaces have been sealed up then the Pots will need to be fitted with suitable terminators to prevent ingress of water....


A Purlin is a horizontal structural beam or member used in the construction of a roof. The Purlin supports the rafters and it is supported by the buildings load bearing walls....


A Rafter is a sloping roof beam used in roof construction. The Rafter forms the carcass of a roof and is typically made of timber....


Refurbishment can be the renovation, decoration or modernisation of (typically) the non-structural elements of a property. Perhaps the most common examples are installing new bathroom or kitchen fittings. Although people often use the phrase “getting a new bathroom/kitchen, ” the...


Render is a covering applied to the outside walls of a building. It can serve two purposes: Aesthetic - some people may prefer the smooth finish of a rendered wall, which can then be painted in any colour. Protection - if bricks are becoming loose or brittle then rendering the outer wall is...


In masonry, Repointing describes repair work that is done to mortar joints. Repointing is an important defensive measure in protecting a home’s structural integrity

Retaining Wall

A Retaining Wall is built for the purpose of holding back land. To illustrate, imagine a raised flowerbed with a wall along its perimeter. This Retaining Wall separates the elevated earth of the flowerbed from the 'ground level'. If the wall were not in place then the flower bed would collapse or...

Reversionary home income plan

A reversionary home income plan allows property owners to give away equity that they have raised without selling it. It is particularly useful for people approaching retirement age, as it allows them to improve their quality of life by remortgaging their home. This home income plan sells the home...

Ridge Tiles

Leaving Ridge Tiles in a poor state can move into bigger problems later and should be attended to if picked up in a Home Buyers Survey.

Rising Damp

Rising Damp describes the gradual upward movement of water in the lower sections of a building's walls by the process of capillary action: where a liquid travels upwards, against gravity, in a narrow tube. This is the result of complex inter-molecular attractive forces between the liquid and...

Roof Truss

The Roof Truss consists of a number of triangle-shaped elements. A typical design found in homes of standard construction consists of rafters and a ceiling joist.

Roofing Felt

The Roofing Felt is impregnated with asphalt (tar/bitumen) and layed in roof structures beneath the tiles in order to add an additional waterproof layer.

Royal Institution of Chartered Surveyors (RICS)

RICS provides the world's leading professional qualification in land, property, construction and the associated environmental issues.


An RSJ or 'Rolled Steel Joist' is s a steel beam, normally used for support in building structures.

Sash Windows

Sash windows are an elegant and traditional feature of many older homes. Unfortunately they can also present owners with a maintenance nightmare.

Septic Tank

A Septic Tank is usually a tank that holds around 5000 to 7000 litres. It serves as an interim between a pipe conducting sewage waste from a building and another pipe leading to a septic drain field. They are not found in cities in the UK but they occur with some frequency in rural areas. Waste...

Sick Building Syndrome

Sick Building Syndrome is a little-understood phenomenon whereby people who inhabit or work in a building share in a similar set of non-specific symptoms.


A Skylight is like a window in that it is built for the purpose of daylighting. However, a Skylight is built into the roof of a building. It is distinct from a dormer window. Skylights are popular in loft conversions and extensions in general. They can save a great deal of energy –...

Soakaway (Dry Well)

A Soakaway, or dry well, is a underground cavity or structure designed to dispose of excess water.


A Soffit is the term used for the underside of any part of a building. More commonly however, the term Soffit refers to the section under the eaves on the external wall of the house.

Soil Vent Pipe


Solid Wall

Solid Walls commonly support the superstructure of a building and may be differentiated from cavity walls.

Spalled Brickwork

Spalled Bricks are highly absorbent and can absorb as much as a pint of water per brick.  This can cause the brick to fail or crumble.  How do you rectify Spalled Bricks?

Stock Condition Surveys

Stock condition surveys are usually implemented by councils, although they can be commissioned privately. They are instigated by institutions and are not appropriate for private home owners, most families and individuals choose a home buyers survey. A stock condition survey involves the inspection...


Subsidence is the term used to describe when a building is damaged by a failure in the ground beneath or around it.   Typically this results in settlement of the building. Sometimes a building can stop 'moving' or 'settle' and if the problem is not overly...

Surface Water Drain

Surface Water Drains, also called storm drains, carry excess water away from a property to prevent seepage into wall fabric and subsequent structural decay.

Sustainable Building

A Sustainable Building (or Green Building) is a building that is designed (or renovated) with consideration towards its impact on the environment. Each year, more and more Sustainable Buildings are built. Some ways in which a Sustainable Building may help the environment are: Energy Efficiency...


Basements and cellars are more prone to damp than almost any other area of your home. They are often submerged in a sodden environment.  In construction, tanking refers to the practice of coating cellar walls to seal them against water - essentially creating a ‘tank’.

The Pyramus and Thisbe Club

The Club was created in 1974 by a group of Chartered Surveyors who specialised in Party Walls. Its website states: "The Club seeks to advance knowledge of party wall legislation and procedure and to promote best professional practice in its application." 

Thermal Movement

Thermal Movement describes the effects of a change in temperature whereby a material contracts or expands. Technically, every substance is affected by Thermal Movement although the degree to which they are affected varies greatly. Another factor affecting the magnitude of Thermal Movement is, as...

Timber Infestation

A Timber Infestation occurs when the larvae or grubs of certain insects, particularly the Lyctidae and Bostrychidae beetle, inhabit the Timber of a building. The pests derive nourishment from the cells of the wood. A Timber Infestation visibly manifests in the form of tiny holes made by these wood...


A roof Valley occurs where a 'V' shape is formed from the meeting of two sloping roofs.

Valley Gutter

A Valley Gutter (sometimes known as a 'Valley Flashing') are waterproof joined lining pieces used in the intersection between roof surfaces that are not parallel.


A Verge is the side of a pitched roof on a building fitted where the roof tiles protrude beyond the gable end.

Wet Rot

Wet Rot is the most common form of wood rot, accounting for the majority of fungi that infest timber and cause it to decay. It occurs when water has penetrated timber. Any dampness that has penetrated timber creates nourishment for fungal spores to grow. For this reason its growth is restricted to...

Wood Boring Insects

A variety of Insects can tunnel into timber. The most famous culprits are various types of Wood-Boring beetles, but weevils and other Insects are also known to infest wood. Although the effects of each species vary in their minutiae, general symptoms include visible flight holes between 1-3mm in...

Wood Rot

Wood Rot is the occurrence of fungal decay in timber.  Broadly speaking, there are two kinds of wood rot: wet rot and dry rot. Wood Rot can be deeply distressing - it blights timber aesthetically and structurally. If it is not treated in its early stages then the costs can be astronomical:...


Woodworm is not a particular type of creature. It is in fact the larval stage of certain beetles' lives. However in general, or slang, the term is used to describe a variety of wood boring insects that infest timber, creating all sorts of nightmares for home owners. Woodworm can be difficult to...

Zinc Roofing

Zinc is sometimes used as a roofing material.  Cheaper than other metal roof coverings (such as Lead or Copper) it more limited as it is harder to work with.