What Happens During Composite Door Installation?
Written by Cornwall Composite DoorsReviewed by Cornwall Composite Doors installersLast updated July 20265 minute read
Short answer
A professional installer removes the old door and frame, checks and prepares the aperture, fits the new composite door frame square and level, seals and insulates around it, hangs the door, fits hardware, and tests operation. A single door typically takes 3-5 hours.
Knowing what happens on installation day helps you plan around it and spot good workmanship. Whether you're replacing a tired uPVC door or upgrading from timber, the process is broadly similar and should leave you with a snug, properly sealed door by the end of the day.
Protecting your home and removing the old door
Fitters lay dust sheets across the hallway and porch before starting. The old door and frame are then removed carefully, particularly around brick or stone reveals where chasing out old fixings needs a steady hand to avoid damaging the surrounding wall.
Checking and preparing the aperture
With the old frame out, the installer checks the aperture for square, level, and any damage to brickwork or old timber sub-frames. Cornish granite and stone openings sometimes need extra care, as they're rarely perfectly true even on older properties.
Want a quick price?
Free survey, no salesman, no obligation.
Fitting the new frame
The new composite door frame is offered into the opening, packed and shimmed until it's plumb, level, and square, then fixed through the frame into sound brick or timber. Getting this stage right is what stops draughts and sticking doors later.
Sealing and insulating
Gaps between the frame and the wall are filled with low-expansion foam and finished internally and externally with silicone sealant. This keeps the installation weathertight and helps the door perform as intended against Cornwall's driving rain and coastal winds.
Hanging the door and fitting hardware
The door slab is hung on its hinges, and the handle, cylinder, and multi-point locking mechanism are fitted and adjusted. Letterbox and spy hole, if ordered, are cut and fitted at this stage too.
Final checks and handover
The installer tests the door opens, closes, and locks smoothly from both sides, checks weather seals are compressing evenly, and clears away all old materials and packaging. You'll be shown how to operate the locking mechanism and given your guarantee paperwork.
Frequently asked questions
Will installation make a mess?
There's inevitably some dust and debris from removing the old frame, but reputable installers use dust sheets and clear away all waste before leaving. Ask your installer about their process if you're concerned about a particular area of the house.
Do I need to be home during installation?
Yes, someone needs to be present to give access and sign off the finished work. Most homeowners stay in another part of the house while fitters work, popping in for the final walkthrough and demonstration.
What if the aperture isn't square?
It's common, especially in older Cornish properties. Installers pack and shim the frame to compensate, and in some cases minor remedial work to the reveal is needed. A proper survey beforehand should flag anything unusual.
Is a building regulations certificate provided?
Yes, a CERTASS-registered installer self-certifies the work against Building Regulations, covering thermal performance and safety glazing, and issues a compliance certificate once the job is complete and signed off.
More installation advice
- How Long Does Installation Take?A single composite door install is usually a same-day job — here's what affects the timing.
- Preparing for Door InstallationA little preparation before the fitters arrive makes installation day quicker and smoother.
- What to Expect After InstallationOnce the fitters leave, a little aftercare and know-how keeps your new door performing well.
