DIY & Building Basics DIY Glossary

Date Published:

25/06/2008

Electricity

Earthing, electricity
Protective multiple earth is a system of electrical wiring in which the neutral part of the circuit takes earth-leakage current to earth. The earth wire gives a safe route for the current if the live wire touches the outer casing, as it’s connected to the metal casing and will blow the fuse.

PIR sensors

Passive Infra-Red sensors activate security lights when they detect heat emitted by the body, rather than by movement. Drawbacks are that some PIR sensors are over-sensitive, picking up the movement of small animals, and that the outside temperature affects them.

Problems

Dry rot
As the name suggests, this needs much less moisture than wet rot and is found instead in areas with poor ventilation. Fungal spores attack timbers (and sometimes masonry) and deterioration progresses at an alarming rate, meaning professional treatment is required urgently. Eliminate any source of moisture, ensure adequate ventilation (by installing airbricks if necessary), cut away any damaged timbers and treat with a chemical eradicator.

Efflorescence

A white powder deposited on walls, as soluble salts migrate to the surface of a wall or ceiling, often indicating dampness.

Penetrating damp

Water permeates the structure of the building, only during wet weather, drying out when the weather improves. More serious cases may mean the wall itself has become porous – more common in older, solid wall structures, it will need to be coated in a waterproofing liquid. Check gutters and down pipes aren’t overflowing. Check out How To Treat Damp for more info.

Rising damp

Water soaking up from the ground permeates the walls to a height of 1m. It may mean the DPC is damaged or missing, or that something – such as earth in a flowerbed – is bridging the barrier. There will be patches of damp or efflorescence. Repair or replace the DPC, remove any bridging materials and treat the interior wall with waterproofing solution (remember this alone will not solve the underlying problem).

Wet rot

Only occurs in timbers that have been exposed to high levels of moisture, often exterior doors and windows when the paint has been allowed to peel. Eliminating the cause of the moisture will stop any further deterioration. Timbers will need to be stripped, treated with a chemical wet rot treatment and repainted, or cut out and replaced in severe cases.

Building

Airbricks
Perforated bricks built into the outside walls of a building to ventilate the space between a suspended wooden floor. They should be positioned every 2m to avoid dry rot developing.

Cement

A fine grey powder made from limestone or chalk and clay that hardens and is often used as a binding material. Used for rendering and bricklaying.

Concrete

A mix of cement and aggregates (usually sand and pebbles). When mixed with water, the cement binds the aggregate into a hard material over the course of three to seven days.

Epoxy resin adhesive

A very strong, rapid-curing glue that binds most materials including metals, rigid plastics, wood and rubber. Often supplied in two tubes to mix immediately prior to use.

First fix

A stage in renovation or new builds when major works are begun on the interior. Builders and carpenters erect the walls, the majority of the plumbing and electrical systems are installed, including boilers and pipes.

Mortar

The adhesive used to bind bricks, usually a mix of cement, hydrated lime and sand mixed with enough water to make it pliable.

Sand and cement mix

To produce the correct mortar for the job, the ratio of soft and sharp sand to cement will vary. Lime and colouring can also be added.

Second fix

Now the location of plugs etc are fixed, the plasters can cover the walls. The electrician returns to connect light switches and sockets, test the system and connecting it to the mains. The plumber connects the sanitary ware, radiators and connects the boiler to the electrics, and tests the system is safe. The carpenter also returns to begin the decorative work.

Snagging

Identifying problems and faults with new-builds and correcting them before the property is handed over. This should be an on-going process during the whole build, but some snags will only come to light after the owner has moved in.

Windows

Aluminium windows
Usually requiring a wooden subframe, they are sold as complete units and require no maintenance.

Dormer windows

Extensions that protrude from a sloping roof to hold a vertical window, can either be gabled or flat roofed. Often found in loft conversions as they increase headroom.

Double-glazed windows

Each pane of glass comprises two (or more) sheets of glass with a hermetically sealed gap between to improve the thermal performance of the glass.

Hardwood windows

Timber-framed windows, often more expensive but offer more character. Maintenance is necessary every five to 10 years, depending on conditions.

Replacement windows

Required when the existing windows have deteriorated. Benefits include better sound and heat insulation, but care should be taken to choose a sympathetic option when replacing windows in older homes.

Sash windows

Vertically sliding windows, operated by weighted pulleys concealed within a box frame. When both top and bottom sashes move, they are called ‘double-hung’.

UPVC windows

Unplasticized polyvinyl chloride (uPVC) is a rigid plastic and is a low-maintenance, low-cost alternative to wood for window frames and sills. A range of colours and finishes are available.

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