How to Measure for a Sectional Garage Door
Measure the width and height of the structural opening of the garage in several places, taking note of the smallest width and height. These dimensions are the most important details when pricing and ordering your door.
Ignore the existing sub-frame when measuring the structural opening, unless you intend to reuse it (which is very rare and generally not recommended when fitting Sectional doors).
Most manufacturers design Sectional doors to be installed to the inside face (Behind) of the garage opening. This is the preferred method as it maximises your drive-through width and height, whilst hiding the frame behind the brickwork. Alternatively, doors can be fitted in-between the opening to maximise the internal length of the garage, though this requires additional bracketry and fascia sections to conceal the frame.
- Measuring for IN-BETWEEN (Reveal) installation
- Measuring for INSIDE (Face-Fit) installation
- Additional information
Crucial Things to Look Out For
Tracking Depth: A Sectional Door opens into the garage horizontally on ceiling rails. You must have clear room equivalent to the height of the door PLUS a further 350mm - 750mm extending into the garage and the tracks are nearly always higher than the door height itself.
Check for Obstacles: Because the door tracks along the ceiling, always check your internal space for standard UK garage obstacles. Look out for gas or electric meters, low hanging strip lights, loft hatches, boiler pipes, or internal pedestrian doors that open inwards.
General Rule of Thumb: The standard ordering size for a sectional garage door is always the in between daylight frame opening size. You must always allow for the surrounding fixing frame, head section, and springs in your calculations!
Sectional Garage Doors In Action
1. Measuring for installing IN-BETWEEN (Reveal) a Garage opening
Note: Do not order a 14' x 7' (4267 x 2125) sectional door and expect it to fit IN-BETWEEN your 14' x 7' garage opening. You must accommodate the fixing sub-frame in your size calculations!
- Measure the Width of your opening from left to right in several places.
- Measure the Height of your opening from the floor to the underside of the lintel in several places.
- Measure the Depth of your garage from the opening to the back wall at ceiling height.
Take the smallest measurements. These structural dimensions will dictate your door ordering size, once you deduct the frame legs and required headroom.
Calculation Example:
- Your structural opening: 2480mm (W) x 2250mm (H)
- Minus side frames: 90mm per side (180mm total)
- Minus head frame (with motor): 115mm total
- Required Door Size: 2300mm (W) x 2135mm (H)
Result: A standard ordering size of 2286mm x 2125mm (7'6" x 7'0") would fit this opening perfectly with a small tolerance. You will need an 'in-between installation kit' and frame leg fascia covers to bridge the remaining gaps.
Please also refer to the 'measuring tab' shown in the online shop when placing any order.
2. Measuring for installing INSIDE (Face-Fit / Behind) a Garage opening
Sectional Garage Doors that are fitted INSIDE the garage (behind the brickwork) are the most popular choice as they maximise your drive-through dimensions and hide the steel frame from the outside.
- Internal Width Space: You need the structural opening width + approx 90mm each side of clear brickwork for the frame legs.
- Internal Headroom: You need the lintel height + between 100mm to 210mm of clear space above it (check individual manufacturer specs carefully).
- Depth: Ensure the headroom space is consistent all the way back into the garage (Order height + 350mm - 750mm).
Take the largest measurements as the ones to use when installing behind an opening. This ensures the frame is completely hidden behind the pillars and the opening dimensions are used to their absolute full potential.
Note: It doesn't matter if the frame does show slightly on one or both sides if it enables the use of a standard sectional door ordering size rather than a bespoke custom build.
Please also refer to the 'measuring tab' shown in the online shop when placing an order.
3. Additional information
Sectional garage doors are quite simply one of the best all-round garage doors on the market for insulation, practicality, security, and general build quality, providing many years of trouble-free use.
The double-skinned steel panels are incredibly strong, whilst the operating gear offers exceptionally smooth, vertical operation. This design means you can park right up to the door inside and out. When fitted with a premium electric operator, some doors even achieve 'Secured by Design' certification, providing genuinely excellent resistance to forced entry.
Due to the immense strength in the door panels, sectional doors can be manufactured up to a massive 8000mm wide by 3000mm high in domestic specifications (utilising heavier-duty commercial operating gear). There is an endless range of designs, colours, materials, and patterns—including stylish window options—meaning there is bound to be a sectional door that suits your property perfectly.
A sectional door really is a 'door for life', so making sure you measure and order correctly is vital. For any assistance or expert recommendations, please email or call us directly on (01926) 463888.
