MGO Fire Door BOM v3

Total Order Material

MGO Board

—

sheets total

MR Ply 5.2

—

sheets · 4'×8'

MR Ply 3.6

—

sheets

Rock Wool

—

pcs · 25×600×1200

🔥 Fire Seal

—

metres · 12×2mm

Door Type	W × H (mm)	Qty	MGO 6×4'×8'	MGO 6×3'×7'	MR Ply 5.2	MR Ply 3.6 (3×7)	MR Ply 3.6 (4×8)	Rock Wool	🔥 Fire Seal

Purchase Order Summary

Example: 900 × 2400 mm door
The door skeleton is built from MGO and MR5.2 strips cut from standard 4'×8' boards (2438mm long). We calculate how much of each board is consumed per door, then add fixed face panels and rock wool fill.

A · MGO Board 6×4'×8' — How many sheets per door?

The skeleton uses strips from 3 zones (A, B, C). For each zone we calculate: what % of one sheet does this door use? Then multiply by the number of skeleton pieces needed.

Zone A & B — Vertical edge strips (left + right sides)

Metre needed	4.8 m	2400mm ÷ 1000 × 2 sides
Can-get per sheet	36 strips (A) / 10 strips (B)	from AutoCAD nesting
Total metre per sheet	87.77 m (A) / 24.38 m (B)	can-get × 2.438m
% of sheet used	0.0547 (A) / 0.1969 (B)	4.8 ÷ 87.77 / 4.8 ÷ 24.38
MGO skeleton pcs	6 (A) / 4 (B)	fixed per door design
Sheets used	0.328 + 0.787	0.0547×6 + 0.1969×4

Zone C — Internal horizontal strips

Metre needed	5.7 m	0.009 × 900 − 2.4 (width-dependent)
Can-get per sheet	20 strips	from AutoCAD nesting
Total metre per sheet	48.76 m	20 × 2.438m
% of sheet used	0.1169	5.7 ÷ 48.76
MGO skeleton pcs	4	fixed per door design
Sheets used	0.468	0.1169 × 4

Face Panels (fixed)

Front + back face

2 sheets

always fixed, regardless of size

MGO total = 0.328 + 0.787 + 0.468 + 2 = 3.583 sheets

900 × 2400 door needs ≈ 3.58 sheets MGO

B · MR Plywood 5.2 × 4'×8' — Same zone logic, fewer pieces

Exactly the same zone A / B / C method as MGO, but MR5.2 uses fewer skeleton pieces: A=3, B=1, C=1. No face panels.

Zone A (0.0547 × 3)	0.164
Zone B (0.1969 × 1)	0.197
Zone C (0.1169 × 1)	0.117

MR52 total = 0.164 + 0.197 + 0.117 = 0.478 sheets

900 × 2400 door needs ≈ 0.48 sheets MR5.2

C · MR Plywood 3.6 — Fixed 2 sheets, size depends on door dimensions

MR3.6 is the outer skin layer. Always 2 sheets per door. The sheet size chosen depends on door width and height to avoid waste.

Rule	Width < 950mm AND Height ≤ 2134mm → use 3×7 sheet
	Either condition exceeds limit → use 4×8 sheet
900 × 2400 example	Width 900 < 950 ✓	but Height 2400 > 2134 ✗
Result	→ use 4×8	because height fails the check

If door is 900 × 2100: both conditions pass → 3×7 sheet
If door is 900 × 2400: height > 2134 → 4×8 sheet

Any door needs 2 sheets MR3.6 (3×7 or 4×8)

D · Rock Wool 25×600×1200mm — Fill the inner panel area

Rock wool fills the inside of the door. Subtract the frame thickness (300mm width, 450mm height) to get the inner fill area, then divide by one piece size.

Inner width	600 mm	900 − 300 (frame offset)
Inner height	1950 mm	2400 − 450 (frame offset)
Inner area	1,170,000 mm²	600 × 1950
One RW piece area	720,000 mm²	600 × 1200

Rock Wool = (900−300) × (2400−450) ÷ (600×1200) = 1,170,000 ÷ 720,000 = 1.625 pcs

900 × 2400 door needs 1.625 pcs Rock Wool

Summary — 900 × 2400mm door

MGO Board

3.58

sheets / door

MR Ply 5.2

0.48

sheets / door

MR Ply 3.6

2 (4×8)

sheets / door

Rock Wool

1.625

pieces / door