Internal or External moldings that are fitted around the timber window or door. Covering the space between the window or door jamb and the wall.

1. Timber Window and Door Glossary
• Accoya™ – Is modified timber. Uses patent technology called acetylation, to
give it long lasting life. 50-year Guarantee.
• Antique Glass – Glass produced by the old-age mouth-blown cylinder
method. The craftsman blows a glass cylinder which is annealed and cooled.
The cylinder is then scored lengthwise, separated, re-heated and folded out
into a flat sheet.
• Annealed Glass – is also known as a standard sheet of float glass. Annealing is
a process of slowly cooling glass to relieve internal stresses after it is formed.
• Architrave – Internal or External mouldings that are fitted around the timber
window or door. Covering the space between the window or door jamb and
the wall. Commonly known as trims.
• Argon – An inert gas used to fill the space between a double or triple glazed
unit, improving heat retention.

2. • Bay Window – a window built to project outwards from an outside wall.
Usually consisting of 2 or more windows, typically found in Victorian period
homes with timber box sash windows.
• Bead – is typically a rounded shape cut into a square edge to soften the edge
and provide some protection against splitting of the timber window or timber
door frame.

3. • Box Sash – (Sash Window) are the traditional up & down or vertical sliding
style of window, where a system of weights and pulleys counterbalance the
sash and enable easier movement of the window. The system would be
housed inside a box, built into the side of each window and hidden from
view. Traditional timber box sash windows are found in many old-style
properties. Now also available using spring balance systems.
• Butt Hinge – Also known as a Mortise hinge, are typically found on traditional
style timber casement windows, used to attach the sash to the frame.
• Casement Window – a traditional style of timber window that opens on
hinges. Can have one, two or more openers.
• Chamfered – The edges have been removed lengthwise at angles.
• D-Handle – A handle found on the top sash (external) of a timber box sash
window. Looks like a D ‘hence the name’.
• Drip Groove – A groove cut in the underside of a timber window or door sill
to prevent rainwater coming back to the frame.

4. • Engineered Wood – Is wood made by compressing layers of timber together
to improve its strength, dimensionally stable, meaning that it warps and flexes
less easily upon contact with moisture. All our standard softwood pine
windows and doors are made this way.
• Eye (Sash) – Sash eyes are used on timber box sash windows to pull the top
sash down by hand or pole.
• Fan Light – a window that is positioned above another window or door. Can
be opened or fixed.
• Fascia – a timber board covering the ends of rafters or other fittings.
• FENSA – Is an acronym that stands for Fenestration Self-Assessment Scheme.
FENSA Certification is for the installation of timber windows and doors to
certify the works meets building regulations.
• Finger Jointed – also known as a comb joint, is a timber window or door joint
made by cutting a set of complementary, interlocking fingers in two pieces of
wood, which are then glued together. Our timber frames and sashes are joined
this way.
• Fixed – A timber window that cannot be opened, sometimes referred to as a
‘fixed sash’.
• Flush Casement Window – Is a window where the sash face will sit flush with
the timber window frame when closed

5. • Glazing Bars – (Astragal / Georgian) – available as face mounted or solid bars.
Original Georgian bars in traditional timber windows would have been holding
individual glass panes in each square, now available as face mounted on
double and triple glazed timber windows.
• Glazing Beads – a length of timber moulded around the inside of a window
frame to hold the glass in place.
• Hardwood – Is wood from a broad leaf tree. We provide our timber windows
and doors in Oak, Meranti and Sapelle hardwoods.
• Head – The horizontal length of timber at the top of the timber frame.
• Head Drip – Head drips are extensions at the top of a timber window or door.
They are a means of channelling water away from the front face of the timber
window or door.
• Horns (Sash) – Small spurs of that project on a Timber Sash Window. Found
on the window sashes, projecting up from the bottom and down from the top
sash. Available in various styles. They were originally designed to strengthen
the mortice and tenon joints of the window and prevent the timber sashes
being opened too far

6. • In Check – Referring to the positioning of a window ‘In Check’ describes when
a window is sat behind the external wall of the property, positioned behind the
wall instead of in the opening, which is referred to as being ‘Flush’.
• Jambs – The sides of a timber window or door frame.
• Lambs Tongue – a type of moulding profile used on timber windows and
doors
• Laminated Glass – is a type of safety glass that holds together when
shattered. In the event of breaking, there is a sheet of laminate that holds the
glass together, between its two or more layers of glass
• Lifts (Sash) – Located at the bottom of timber box sash windows. Used to lift
the bottom sash
• Meeting Rail – the part of a timber sash window where the two sashes meet
and create a weather barrier in the middle of the timber window.
• Mullion – Vertical length of timber, internal of timber window frame. This
separates different sections of a timber casement window giving strength to
larger frames.
• Obscure Glass – (Opaque) is textured glass designed to separate spaces and
“obscure” visibility between the spaces. Different designs have different levels
of Obscurity.

7. • Opener – is the opening part to a timber casement window.
• Ovolo – a type of moulding profile used on timber windows and doors
• Pane – a single sheet of glass in a timber window or door.
• Parting Bead – Is a thin length of timber let into the pulley stile to keep the
timber sashes apart.
• Pulley (Sash) – Found at the top of timber sash window frames, ironmongery
used to hang sash cords to open and close a cord hung timber sash window.
• Preservative Treatment – a coating applied to timber windows and doors as
a protection against decay, weather and insects.
• Rebate – A cut in a timber frame designed to allow a door or window to close
against it.
• Reveal – the area around where the timber window or door has been fitted.
• Sash – the internal framings of a timber window. Timber casement windows
and timber sash windows both can have sashes. These are usually the opening
parts to the windows, but ‘Dummy’ sashes are also produced that look the
same for fixed areas.

8. • Sash Cords – The cords found on traditional timber sash windows that use
‘Cords & Weights’ system. Used to attach the weights to the timber sashes
using pulleys in between.
• Sash Weights – the weights used to counterbalance the sashes in a timber
sash window.
• Sash Windows – (Box Sash) are the traditional up & down or vertical sliding
style of window, where a system of weights and pulleys counterbalance the
sash and enable easier movement of the window. The system would be
housed inside a box, built into the side of each window and hidden from view.
Traditional timber box sash windows are found in many old-style properties.
Now also available using spring balance systems.
• Secondary Glazing – Is the installation of a fully independent window frame
on the inside of an existing timber window.
• Secured-By-Design (SBD) – is a flagship initiative by the Police Force in the UK
to support the designing out of crime. The criteria focus on the prevention of
crime through a few different methods. This includes the design of timber
windows and doors.
• Sill – a ledge or sill forming the bottom part of a timber window, enabling
water to run away from the face of the building.
• Soffit – the underside of a building such as an arch, a balcony, or overhanging
eaves
• Softwood – the wood from a conifer (such as pine, fir, or spruce). Our
standard timber windows and door are made from European pine.
• Spacer Bar – is the continuous hollow Aluminium frame that separates the
two glass panes in a double-glazing or triple glazed timber window. The spacer
bar is bonded to the glass panes via a primary and secondary seal, creating an
airtight cavity which is filled with air or gas. Warm edge spacer bars are
available that help improve the Uvalue of a sealed unit.

9. • Spacia Glass – In Pilkington Spacia ™, the air between the two panes of glass
is extracted, creating a vacuum. Giving unbeatable U-values and very slim
frames. Can be used in timber conservation windows and doors.
• Spiral Balance – a modern alternative to the classic Cords & Weights system,
the spiral mechanism allows a timber sash window to open and close. By
tensioning a spring to counterbalance the weight of the sashes.
• Staff Bead – the moulded timber beading that holds the timber sashes in
place.
• Stained Glass – coloured glass used to form decorative designs. Typically, by
setting contrasting pieces in a lead framework like a mosaic and used
traditionally in timber front doors.
• Stormproof Casement Window – Is a timber window where the sash
overlaps the frame to create a tight seal when the timber window is closed.
• Transom – Is the horizontal length of timber within a timber window or door
frame.

10. • Toughened Glass – (Tempered) Is a type of safety glass processed by
controlled thermal or chemical treatments to increase its strength compared
with normal glass.
• U-Value – Is the rate of transfer of heat through a structure (which can be a
single material or a composite), divided by the difference in temperature
across that structure. The units of measurement are W/m²K.
• Window Board Groove – Is a horizontal grove cut along the bottom of a
timber sash window frame. Allows window boards to be joined to the timber
sash window.