BWF – CERTIFIRE certification validates these products suitable for use as fire doors and provides the means to independently authenticate the quality and performance of the doors to which this applies.

IVchord piano

The fourth scales step is F, which result in the F chord. The fourth note of a scale is also referred to as the subdominant. Whereas the fourth degree is major in the context of the Major scale, the fourth degree is minor in the Minor scale. For example, Fm (iv) in the C Minor scale. Another example is F#dim (iv#) in C Lydian mode.

IVchord guitar

C major key = F major C# major key = F# major D major key = G major D# major key = G# major E major key = A major F major key = A# major F# major key = B major G major key = C major G# major key = C# major A major key = D major A# major key = D# major B major key = E major

IVchord in C major

BWF – CERTIFIRE system involves rigorous type testing, audit testing and factory production control combined with current fire test evidence and ISO90001 Quality Assured production, ensuring that the fire doors supplied will provide the same level of performance as those tested.  The BWF-CERTIFIRE scheme is the authoritative voice in fire door safety and has widespread acceptance by the enforcement authorities – Building Control, the Fire Brigades and Trading Standards.

IIVV chord progression in C

Critical to the identification of these fire doors is the permanent tamper-evident label affixed to every door.  This label gives details of the door’s fire rating, certification number, details of the manufacturer or supplier and a unique number for each individual door.  All this provides specifiers, regulators and purchasers with the certainty that the fire doors will fulfil the standards expected of them.

As an independent scheme, in addition to awarding the certificates, CERTIFIRE undertakes regular factory inspections of fire doors and door sets in production to ensure the tested standards are consistently maintained.

We supply JB Kind interior and exterior doors throughout the UK. One of the most popular doors is an Oak finished door. As well as doors we have a full range of Karcher Handles, Karcher Knobs and Karcher Accessories to complement your door. Doors can be delivered throughout the UK, for carriage costs please use our calculator. You can also find a range of Eclisse Pocket Doors on this site, which are available in a range of UK standard doors sizes. All prices shown exclude VAT, unless otherwise stated.

A minor key = Dm A# minor key = D#m Bm minor key = Em Cm minor key = Fm C#m minor key = F#m Dm minor key = Gm D#m minor key = G#m Em minor key = Am Fm minor key = A#m F#m minor key = Bm G minor key = Cm G# minor key = C#m

Roman numerals in music refer to chords based on scale steps. The IV chord can mean different things depending on the actual musical key. In the key of C major, the IV chord is F.

The benefit with Roman numerals is that chord progressions can be transposed to other keys. One of the most played progressions of all is the I - IV - V progression with the tonic, the subdominant and the dominant degrees. A similar variation is I - V - IV, that is also extremely common. These can also include extended chords: Dmaj7 (Imaj7) - G6 (IV6) - A7 (V7); Emaj7 (Imaj7) - B11 (V11) - Amaj7 (IVmaj7). See also Chord theory | Music theory.