Installation of Windows and Doors Help Guide
Installation Help Guide
This page explains the recommended process for surveying, measuring, installing, sealing, glazing and commissioning aluminium windows and doors.
Following these guidelines helps ensure your products are installed safely, perform correctly and provide long-term durability.
1. Site Survey
A proper site survey is the foundation of a successful installation. The survey confirms the customer’s requirements, assesses the structural opening, identifies any special conditions and ensures accurate measurements are taken before manufacturing or installation begins. Installation Help Guide
During the survey, the installer should confirm whether windows or doors open inward or outward, along with hardware requirements, handing and configuration. The existing installation should be recorded, including opening sizes, mullion and transom positions, and the overall style of the current window or door.
The structural opening must be checked for defects such as cracks, damp issues or structural weaknesses. If problems are discovered, responsibility for repairs should be agreed before installation begins.
The survey should also identify any cables, aerial wires, telephone lines, curtain tracks or other services around the opening that may interfere with installation. Any required brickwork removal, cavity closure or additional preparation should be discussed and agreed in advance.
2. Measuring the Opening
Accurate measurements are essential to ensure that the correct frame size is manufactured to suit the constructed opening.
Surveyors should take three measurements for both width and height, using the smallest measurement to determine the tightest point – diagonal measurements should also be taken to check the squareness of the opening.
Where a projection cill is required, the nose of the cill should project between 25mm and 40mm beyond the external face of the building to provide the correct deflection of rain water.
External finishes should be verified to ensure that opening sashes will clear render or cladding finishes in the reveal area and/or that framework is not excessively covered. In some cases, wider frame profiles may be needed to overcome external finishes and this consideration also applies to heavy plaster work and tiling on the inside that may impact frame cover.
For some projects, manufacturing dimensions can be agreed during the design stage between the architect and builder who will sometimes construct around formers to ensure opening accuracy.
FOR MORE MEASURING ADVICE READ OUR DEDICATED GUIDE
3. Preparation & Removal of Existing Windows or Doors
Before installation begins, installers should confirm all documentation, drawings and survey information are correct and that the products match the required sizes and specifications.
The property must be protected during the installation process – floors, decorations, nearby furniture and patio/garden areas should be covered or items moved to prevent damage.
Existing windows and doors should be removed carefully to avoid unnecessary damage to surrounding structures. Where possible, removal and installation should take place on the same day to maintain security and weather protection.
If electrical cables or other services are present near the opening, they should be safely rerouted around the frame rather than through it wherever possible.
Installers must follow safe working practices at all times, including the use of appropriate personal protective equipment and safe handling of glass and power tools
4. Installing Aluminum Windows and Doors
Aluminium frames must be installed plumb, level and square to ensure perfect operation – incorrect positioning may cause function problems, distortion or poor sealing. Where possible, frames should be secured on all four sides.
Typical fixing guidelines include:
- Starter fixings positioned 150 mm in from each corner
- Intermediate fixings spaced no more than 600 mm apart
- Fixings placed at least 100 mm away from mullion or transom centre lines
- At least two fixings on each jamb
- Additional head and sill fixings for units wider than 1800 mm
Installation packers should be used directly next to fixing points to prevent distortion of the frame – packers must be strong, durable and resistant to compression or corrosion.
All frames should bridge the damp proof membrane where present – open cavities should be insulated and properly sealed while maintaining the integrity of the damp proof barrier.
5. Fixing Methods
Two main fixing methods are commonly used to install windows and doors:
Through-frame fixing – where fixings pass directly through the frame into the perimeter structure.
Lug/strap fixing – where metal brackets attached to the frame are internally fixed into the surrounding structure.
The correct method depends on wall construction, frame location, reveal design and load requirements.
Fixings must be capable of resisting wind pressure, operating loads, gravity forces, accidental impacts and potential intruder attempts.
Expanding foam must never be used to secure frames in place and should only be used as a last resort to aid as a gap filler.
All in all an excellent job well done. The new bi-fold doors look really good!
6. Glazing
Windows and doors may arrive pre-glazed or may require glazing on site.
All insulating glass units should be inspected before installation. Damaged glass must never be installed.
Correct glazing procedures include installing:
- Setting blocks
- Location blocks
- Gaskets or glazing tapes
- Glazing beads
- Sealants where required
Safety glass must always be positioned correctly according to regulations, with visible safety markings.
Low-emissivity coated glass units must also be installed in the correct orientation to ensure thermal performance is maintained.
7. Sealing
Perimeter sealing prevents water penetration and reduces air leakage between the frame and the building structure.
Sealants should be selected based on the frame material, substrate, joint size and expected movement. Most installations require low-modulus, high-elasticity sealants designed to accommodate building movement.
Sealants must be compatible with both the frame and surrounding materials. Any existing mastics or contaminants should be removed before applying new sealant.
Backing materials should be used where required to ensure proper sealant depth and adhesion.
Where trims or pressings are used, they should be colour matched and suitable for external weather exposure.
8. Finishing and Making Good
Once installation is complete, the surrounding area should be cleaned and all debris removed. Drainage paths should be checked to ensure they are clear.
Internal reveals should be finished as agreed with the customer and prepared for redecoration if required.
Protective tapes applied during manufacturing should be removed promptly to prevent adhesive residue from damaging the frame finish.
In most cases, sand and cement should not be used to fill the gap between the frame and wall unless specifically required for specialist installations.
9. Commissioning and Handover
After installation, a final inspection should be carried out with the customer where possible.
The installer should demonstrate how to correctly operate the windows or doors, including:
- Opening and closing
- Locking systems
- Restrictors
- Emergency escape functions where applicable
Customers should receive operating and maintenance instructions, along with information about replacement keys and future servicing if required.
Ideally, the customer or their representative should confirm that the installation meets expectations before the project is signed off.
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Frequently Asked Questions
If you require any support, please don’t hesitate to review our FAQ’s below or drop us a message on our contact form here
When should windows and doors be installed during a build?
Installation should be scheduled as late as possible in the build process to reduce the risk of damage to factory-finished products.
What checks should be done before installation begins?
Before installation, installers should:
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Verify sizes and types against survey details
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Check aperture dimensions
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Ensure all documentation and equipment are available
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Inspect products for damage
Why are packers used during installation?
Packers are used to:
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Keep the frame square and level
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Prevent distortion when tightening fixings
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Provide support at key fixing points
How energy efficient are your windows & doors?
All of our products are very thermally efficient; they meet and exceed all current building regulations.
Our aluminium profiles are thermally broken and benefit from high performance double glazing with a centre pane U Value of 1.2 W/m2 as standard. The maximum overall U value of any of our products is 1.6 W/m2, with many of our door and window products offering even lower U Values.
What information must be provided in order to get an accurate quotation?
We will ask you to provide the following information:
- Approximate dimensions (width x height)
- Basic design/layout
- Project location
How long will my quotation take?
We aim to return all quotations within 24 hours however large projects may take longer.
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Aluminium Bi-fold Doors, Sliding Doors, Contemporary Glazing, Aluminium Heritage Windows and Traditional Steel Replacement Doors
