EXTERNAL FEATURE DEFINITIONS OF BUILDINGS
CHIMNEYS AND ROOFS

Party Structures . - Party Wall Act Etc. 1996
A structure which both parties enjoy the use of or benefit from. An example of this would be where both parties gain support from a wall or utilise a common chimney or chimneys with respective flues in either side. In terraced housing the wall between the two properties is the party wall.
Any work to party structures, such as party walls or party chimney stacks, require agreement under the Party Wall Act.
Tile on Edge
A tile sitting sideways, bedded in cement mortar which is being utilised as a flashing, this is not an ideal material. We would always recommend the use of lead flashings.
Flaunchings
A low, wide cement mortar fillet surrounding the flue terminal on top of the chimney stack to throw off rainwater.
Flashings
Flashings prevent dampness from entering the property, usually at junctions where materials change. Such a junction is the one between the chimney and the roof. Flashings in this area are traditionally made from lead.
Flashband
Flashband is a sticky backed thin flashing which is best used for temporary repairs only.
Soakers
Soakers are the upstand below the flashings and direct rainwater away from the tile or slate edge
Spalling
Spalling occurs to brick or stone when water penetrates the surface and via freezing and thawing starts to cause deterioration to the surface. This in turn allows further water penetration and the surface breaks up further. This ultimately can lead to water damage or structural damage to the area.
Re-Pointing
Re-pointing is carried out where the existing mortar has failed and broken away to stop damp penetration and further deterioration. The mortar should be raked out to approximately 20mm and then replaced with a mortar of a similar type, therefore, stopping damp penetration occurring.
Capping
Capping is a practice used when chimneys are no longer in use to prevent moisture from entering the structure in the form of rainwater via the chimney. This usually involves the closing of the chimney with a tile or slab positioned across. It should include vents to allow air circulation.
Parapet Walls .
These walls are usually above the roof line and often sit on the boundary of the property. Due to their position they are relatively exposed and suffer from deterioration due to the elements.
Blinding .
On a roof this is where a mortar is used to bed slate or tile.
Polycarbonate
Transparent, extremely tough plastic sheet, used for security glazing. It may also be an insulating light panel, double walled or triple walled, or 10 or 16mm thick. It is not a fire hazard as it has low ignitability and low flame spread, and releases little heat and little smoke if burnt. It can be coated to resist damage from ultraviolet.
Proprietary Flashings
These are usually supplied by the manufacturer of the roof covering and will be specially made to fit the profile of the roof covering. Typically they are aluminium.
Cement Fillets/Cement Flashings
This is where cement has been used to cover up or fill the junctions between two areas, for example between a roof and a wall to help prevent dampness. Cement is a brittle material and prone to cracking which in turn allows dampness into the structure. we would always recommend they are replaced with lead.
Torching
Usually lime mortar dabs (but can be moss) which the slates sit upon. These are used to reduce the wind traveling through the building therefore reducing the risk of wind damage.
Nail Sickness .
The weakening of the nails which fix slates or tiles to the roof battens rusting. This is normally attributed to problems with slate roofs.
Lead Tingles or Lead Slaps
These are strips of lead usually about 25mm wide which are used to secure slates where they have slipped.
Turnerising
"Turnerising" is a process used usually when roofs have started to deteriorate or leak and it involves the covering of a roof with a mesh and coating in bitumen. It is almost impossible to economically save or re-use materials which have been treated in this manner.
Nibbed Clay Tiles
A nibbed tile is one which has raised areas known as nibs, usually two in number, at the top of the tile to enable the tile to be fixed to the roof batten which, in turn, fixes to the roof structure.
Delamination
This occurs in items built up of layers. It simply refers to the layers breaking down.

EXTERNAL JOINERY

Over Lights (or fan lights)
This is a window above the door allowing light into the hallway area. Sometimes also known as fanlights
Secondary Glazing
This is where a secondary window has been added, usually to prevent draughts. We would also draw to your attention that these type of windows can be restrictive in the case of the emergency when, for example, a fire has occurred in the property.
Trickle Vents
Small vents to the windows to allow air movement inside the property to stop a build up of fumes or humidity.

GUTTERS AND DOWNPIPES

Surcharging
This term is usually used in relation to valley gutters and is where there is too much rain for the valley gutter to cope with.

WALLS

Cornice (external)
This is the top course of bricks where the house meets the roof.
Efflorescence
This is where salts appear on the surface of the brickwork, render or plaster in a white dust or crystal formation
Lime Mortar
mix used to bed bricks upon; its characteristics being that it flexes and moves with the structure. It was used up to the War years.
Cement Mortar
sand cement mix used commonly in brick houses from about the First World War onwards and is relatively strong and brittle and therefore does not allow much movement.
Re-Pointing 
Re-pointing is carried out where the existing mortar has failed and broken away to stop damp penetration and further deterioration. The mortar should be raked out to approximately 20mm and then replaced with a mortar of a similar type, therefore, stopping damp occurring.
Engineering Brick
A clay brick of high compressive strength and low absorption, eg Staffordshire blue bricks and some reds. Class A bricks are stronger than 70 N/mm² and have an absorption below 4.5%. Class B have a 50 N/mm² compressive strength and maximum 7% water absorption.
Fletton Brick 
A low cost pale red brick made from Oxford clay with traces of coal that burn during firing, saving energy. It is pressed like many clay bricks and can be sand faced, pigmented, or textured for use as facings.
Bonding Timbers
These are timbers used in construction of walls usually using a lime mortar construction. Bonding timbers are used horizontally and add strength to the wall enabling additional lifts of brickwork.
Render
A sand and cement coating applied in two or three coats or layers.
Bell-Mouths
A bell-mouth is a curve usually formed by use of a metal bead, at the base of a wall which throws the water away from the structure therefore preventing dampness.
Pier
This can be the load bearing brickwork in a wall between openings, or a short buttress on one or both sides of a wall, bonded to it for stability.
Cavity Wall Ties
A fastener across a cavity wall to hold the two leaves together. Now usually made of stainless or galvanised steel wire or strip, sometimes plastic, and has a twist or bend near the middle to form a drip so that water cannot pass. Wall ties are built into the brickwork bed joints as work proceeds and may have a large plastic washer to hold cavity insulation in place. In the early days of wall ties they were manufactured from a low grade steel or iron which was prone to decay causing them to expand. This is characteristically identified by horizontal cracking through brickwork courses and in extreme cases a gap clear through the wall revealing daylight from the inside.
Recessed Joint
A mortar joint set back about 6mm from the face of the wall, either a raked-out joint or one made by tooling. It is used for brickwork, and for stonework to prevent flushing, and is strongly shadowed.
Influencing Distance
This is the distance in which a tree may be able to cause damage to the subject property.

DEFINITIONS OF OUTSIDE AREAS

Bund Wall
A lined wall around oil tanks designed to catch l oil that leaks from it. It therefore should have the capacity to retain the volume of oil held within the oil tank and also be oil tight.
Back Siphonage
The sucking back of dirty water from within a building leading to backflow into a water main if its pressure drops. All water authorities have regulations to prevent this pollution of the main, eg. by having an air gap under the draw-off taps of sinks or drinking fountains, or ballvalves of cisterns. A ballvalve with a silencing pipe must have an anti-siphon hole
Benching
Concrete in the base of an inspection chamber, cast to form a deep channel sloping gently up to the walls each side. It ensures that no solids are left after flooding and is stood on when rodding.
Manholes
As part of the current Building Regulations, you are required to have a manhole (or in some instances a rodding eye is allowed) at each change of direction of the drains or where new drains join an existing run.
Rodding Eye
This is a small access hatch that is used for rodding the drains should they block.