Steel BeamInstallers
Rear wall opened for wide doors with a galvanised steel beam and props, garden beyond

Bi-fold & sliding door openings · Bordon

Bi-fold & sliding door openings in Bordon

Bi-fold & sliding door openings for homes in GU35, designed by a structural engineer.

  • Price fixed in writing once scope is agreed
  • Building control arranged
  • Temporary works and making good included

Free survey in Bordon

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  • Free survey visit
  • Engineer's calculations arranged
  • Building control handled
  • Fixed written price once scope is agreed
  • England, Wales, mainland Scotland & NI

Bi-fold & sliding door openings in Bordon: how it works

Bordon has a mix of housing, and bi-fold & sliding door openings need a slightly different approach in each. We also work in nearby Basingstoke, roughly 14.2 miles away. Whatever the age of the property, the steel goes in on proper bearings with temporary support in place throughout.

Replacing a window or narrow patio door with a full run of bi-fold or sliding doors opens a room to the garden. Because it is an external wall, the opening usually carries the first floor, the wall above and sometimes roof loads, and the new steel has to work with the doors as well as hold the house up.

Worth knowing before you start

  • Very wide openings, or ones that run close to the corner of the house, may leave too little wall for the beam to bear on. In that case the engineer may specify steel columns or a goalpost frame standing on its own foundations.
  • Glazed doors need a stiffer beam than a plain opening of the same width. If the steel bends even slightly under load, folding panels can bind, sliders can stick and glass can be stressed, so the engineer sets a tighter deflection limit for door openings.
  • External walls can have gas meters, boiler flues, soil pipes, outside taps or cables near the new opening. These are found at survey and moved by the right trade, with any gas pipework done by a Gas Safe registered engineer as the law requires.
  • Door suppliers quote a structural opening size, which allows for the frame and fixing tolerances. Agreeing that size before the steel is designed avoids reveals that are too tight or gaps that have to be packed out later.
  • Both leaves of a cavity wall need support over the opening. Depending on the design, the outer brickwork may sit on a plate fixed to the beam or on a separate external lintel, and the engineer specifies which suits the loads and the look.

What happens, step by step

  1. Look and measure

    We check the wall, the span you want and what the wall is carrying, and photograph anything the engineer needs to see.

  2. Design and price

    Calculations come back from the engineer and we confirm your fixed written price, line by line.

  3. Building control

    We submit a building notice or full plans application to the local council's building control team, so approval is in place before the wall is touched.

  4. Fit, inspect, finish

    The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.

What do bi-fold & sliding door openings cost in Bordon?

As a guide, budget £2,800–£7,850 including VAT for rear wall opening for bi-fold or sliding doors in Bordon, based on published UK cost guides adjusted for prices in the South East (+12%).

JobTypical guide rangeWhat it usually covers
Rear wall opening for bi-fold or sliding doors£2,800–£7,850External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately)
Opening into a rear extension£2,800–£7,850Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build
Steel goalpost frame£2,250–£6,700Two posts and a beam bolted as a frame, pad foundations, base plates and fitting
Lintel replacement£450–£1,340 per lintelPropping, removing the old lintel, new lintel set on beds and brickwork made good

Figures include our approximate regional adjustment for prices in the South East (+12%) and are rounded. How these figures are worked out.

Approvals in Bordon

Structural openings in English homes need building regulations approval before work starts. The local council's building control team can deal with it, or you can use a registered building control approver. Either way the steel is inspected before it is covered, and a completion certificate is issued at the end. Keep it safe for when you sell.

If the beam bears into a wall you share with a neighbour, the Party Wall etc. Act 1996 applies, and a party structure notice must be served at least two months before that work starts. We arrange this through a party wall surveyor.

Building rules in England

Bi-fold & sliding door openings near Bordon

Questions about bi-fold & sliding door openings in Bordon

How soon can bi-fold & sliding door openings start in Bordon?

Start dates depend on the engineer's calculations, the building control approval and, where needed, party wall notice periods. We give you a realistic timetable after the survey and keep you updated as each approval comes through.

Do you also work near Bordon?

Yes. We also cover nearby towns including Farnham, Aldershot, Fleet and Godalming.

Why does the beam need to be stiffer for glazed doors?

Because glazed doors tolerate very little movement. Every beam bends slightly under load, and with bi-folds or sliders that movement can make panels bind, tracks drag or glass crack. The engineer sets a stricter deflection limit for these openings, which often means a heavier section than strength alone would need.

Can I have a level threshold with bi-fold doors?

Often yes, but it has to be designed. The inside floor, outside paving and drainage all need to work together so water cannot run in, usually with a drainage channel outside and the right damp-proof detail under the door frame. We look at levels at the survey and plan the threshold with the door supplier.

Do I need a steel beam for bi-fold doors?

Usually, yes. Bi-fold and sliding doors need wide openings, and in a load-bearing external wall that span is normally carried on steel. The engineer designs it for strength and stiffness, because glazed doors can stick or be damaged if the beam deflects. A small opening under light loads might only need a lintel, but that is the engineer's call.

Can you work on older or listed homes in Bordon?

Yes. Older homes often have lime mortar, timber lintels or shallow footings, which the engineer allows for. Listed buildings need listed building consent for internal structural changes as well as building regulations approval, and that must be in place first.

Planning to take a wall out?

Book a free survey visit. You get an itemised written quote covering calculations, building control, steel and making good.