Frequently Asked Questions on Garage Doors

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Our full list of Questions and Answers is shown below, click on the more link to see the detailed answers to some of the questions.


When measuring for any garage door always remember there is a fixing sub frame to include in all calculations, below is a guide on how to measure for an up and over door. When measuring for an up and over door it is important to start by measuring the width and the height in several places from the top to bottom and left to right to find the smallest dimensions which become the key measurements you work with.

Measuring when reusing an existing timber sub frame
Most up and over garage doors we supply have factory fitted steel sub frames, providing better security and stability overall. However, sometimes it is easier to replace the existing garage door and mechanism but leave the old timber sub frame in place. (You cannot reuse an old steel sub frame as they all vary so much and have different anchor points depending on the year of manufacture and the door model so always replace a steel framed door completely). So, if you are leaving the timer sub frame in place then the easiest way to get your measurements to actually order the up and over door is to measure the internal timber frame dimensions only. As long as the timber sub frame is not less than 70mm wide on the inside face all round then most up and over doors will install directly back onto this frame. Measure your existing frame and for example if you have a 2134mm wide (7'0") and 2134mm (7'0") high internal frame size then the new door ordering size will be 7'0" x 7'0". Most up and over standard sized garage doors are ordered in imperial dimensions and don't always necessarily tie up exactly with the metric sizes and are different by a few millimetres. There is some tolerance built into the door panel itself (about 10mm in the width and height).

Measuring for installing INBETWEEN a garage opening
When installing a complete new door, gear and sub frame in-between a garage opening then all you need to focus on is the width and height in-between the garage opening as everything ordered will fit in-between this opening. Be aware of checking whether the opening is square in the measuring process as this can be a huge problem when installing if it is not square. Take notice of the OVERALL dimensions of your chosen manufacturer and model and make sure they are smaller than your measured opening sizes. (You always need a tolerance when fitting anything in-between a structural opening. Never order exactly the same size as the opening or you will not be able to get the door and frame into the opening!) N.B. Take note of any potential obstructions internally - A canopy type door will protrude into the garage about a third of its height and a retractable type door will have horizontal tracks coming into the garage about the same height as the door ordered. Important: ALL up and over garage doors require a fixing subframe for installation and this must be taken into consideration when measuring, ordering and installing.

Measuring for installing BEHIND a garage openingdoor and frame behind opening
When installing a complete new door, mechanism and sub frame behind a garage opening then all you have to be aware of is making sure the garage opening is wider and higher than your chosen door ordering sizes, but ideally not wider or higher than the overall door and frame dimensions. simple. The sub frame will fit to the back of the opening, so whether the opening is square or not is also not quite so important if there is enough tolerance.

Ordering a New Up and Over Door
Up and over garage doors are always ordered by their internal fixing subframe dimensions in the U.K. - in other words the internal width and height of the sub frame opening which is usually either timber or steel box section. The exceptions are the available purpose made up and over doors, where both measurements are always best if ordering with a steel fixing subframe. Tell us the overall width and height required with the frame and the opening size inside the sub frame, this way we know it has been understood before manufacturing. For pricing purposes the ordering size refers to the dimensions in between the sub frame.

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Further Information:



Sectional garage doors are available in a far wider range of sizes, including purpose made sizes up to 8000mm, so measuring and ordering is relatively easy once you understand the additional dimensions over and above the door ordering sizes.
ALL sectional garage doors are ordered by the internal dimensions of the steel fixing frame opening and all sectional doors have a steel framework for installation, this must always be taken into account.
Do not order a 14' x 7' (4267 x 2134) sectional door and expect it to fit INBETWEEN your 14' x 7' garage opening, there is always a fixing sub frame to accomodate as with almost all other garage doors!
Ideally, a sectional garage door is installed BEHIND the structural opening and therefore ideally the ordering size is the smallest measurements taken for the width and the height, however more and more sectional doors are being fitted INBETWEEN the opening and we can accomodate all our sectional doors to fit this way as well.
i.e. Measure your opening at 2286mm wide and 2125mm high and this is the ordering size for the sectional door. You must measure the inside faces of the structural opening including the internal headroom above the lintel/RSJ and also measure into the garage as a sectional door will some a lot further into the garage than an up and over door. You can download our sectional door ordering form to assist in this process. (see bottom of page)

The tracks that the door slides up in will curve a full 90 degrees and enter the garage horizontally so you require headroom for this and depth for the tracks.
The headroom required will also vary from different manufacturers and sizes of door. Most sectional garage doors are installed behind (inside) the garage opening to maximise drive through dimensions and most have quite large space requirements for the frame legs and the height required for the curved part of the track the door panels move in. However, because a sectional garage door does not go through the opening it is possible to install sizes larger and smaller than your actual opening on the width and height. Very rarely will a standard size sectional door be the exact size when replacing an old door.  A lot of sectional doors have to be installed IN-BETWEEN the structural opening for various reasons and most leading manufacturers will now offer an additional fitting kit of braces to make this possible with the added option of trimming sections to help match the door frame and finish.
Generally, most sectional domestic garage doors require 90mm each side for installation and between 100 and 210mm of headroom above the top panel of the door for the headroom. (Check each manufacturer carefully before committing). A sectional door will also come into your garage a lot further on the horizontal rails, so it is essential you have clear room at least the height of the door plus a further 350 - 600mm (on average) into the garage.

Summary for Ordering: The ordering size for sectional garage doors is always the daylight frame opening size (allow for the fixing frame dimnsions and springs in your calculations)
Please also refer to the 'measuring tab' shown in our online shop for each sectional door when specifying and placing your order. If you have any doubts please contact us for verification.
Our online ordering system will also provide you with a confirmation order and drawing to check before we actually order your sectional door.

A timber sub frame can also used to create a reveal structure if you do not have piers to install behind.
Hormann, Garador, GDO, Seceuroglide and Carteck do offer an inbetween fitting kit for this purpose as well with additional cover profiles to close up any gaps and trim up the sides and head section.

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