Steel BeamInstallers
Basement conversion with steel beams and a steel column on a concrete floor

Basement & cellar steels · Antrim

Basement & cellar steels in Antrim

Basement & cellar steels for homes in BT41, 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 Antrim

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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

About our basement & cellar steels service in Antrim

We carry out basement & cellar steels in Antrim, covering the BT41 postcode district. The wider Antrim and Newtownabbey area is covered as well. The job starts with a free survey visit so the engineer's calculations are based on your actual walls, floors and loads.

Underpinning and waterproofing are specialist trades, and we coordinate the steelwork with them rather than replacing them. Our part is the engineer's steel design, building control, temporary propping, and fitting the beams, columns and base plates at the right point in the dig, so the structure is sound before finishes go in.

Worth knowing before you start

  • Below-ground rooms need a waterproofing design, often a cavity drain membrane, a tanking system or both. Column bases and beam bearings that pass through the waterproofing are detailed so they do not become a route for water.
  • Underpinning deepens the existing foundations so walls can go lower, and a specialist carries it out in a strict bay-by-bay sequence. Steelwork has to fit around that sequence, which is why the engineer plans the two together from the start.
  • A basement room needs a safe way out in a fire, which affects the stair, the doors and sometimes an escape window into a lightwell. Steel in the basement ceiling also commonly needs fire protection to the standard building control asks for.
  • Cellars often house gas meters, the incoming water main, the electricity supply and old drainage. These are mapped before work starts, gas work must by law be done by a Gas Safe registered engineer, and the electricity network operator may need to move a supply.
  • Basement steel frames often rely on columns because there is nowhere else to land the load. Each column sits on its own foundation or a thickened part of the slab, and its position needs agreeing early so it does not end up in the middle of a room.

From survey to sign-off in Antrim

  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

    A full plans application or building notice goes to Antrim and Newtownabbey Borough Council under the Building Regulations (Northern Ireland) 2012 before work begins.

  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.

How much should I budget in Antrim?

As a guide, budget £2,150–£5,600 including VAT for basement or cellar steelwork in Antrim, based on published UK cost guides adjusted for prices in Northern Ireland (-14%).

JobTypical guide rangeWhat it usually covers
Basement or cellar steelwork£2,150–£5,600Beams and columns with pad foundations under the floor above (excavation and waterproofing extra)
Building control fees£220–£560Building notice or full plans fee and inspections; varies by council or approver
Structural calculations for a beam£220–£640Site measure or photos, beam and padstone design and calculations for building control
Fire protection to a steel beam£130–£520 per beamFire-rated board boxing or an intumescent coating system as specified

Figures include our approximate regional adjustment for prices in Northern Ireland (-14%) and are rounded. How these figures are worked out.

Building rules for Antrim

Removing a load-bearing wall in Northern Ireland needs building control approval from the council. Antrim and Newtownabbey Borough Council covers Antrim. The engineer's calculations support the application, and a completion certificate is issued after the final inspection.

Northern Ireland has no Party Wall Act, so there is no statutory notice to serve. Where the steel bears into a shared wall, the title deeds and the general law apply, and agreeing the work with your neighbour in writing first is good practice.

Building rules in Northern Ireland

Basement & cellar steels near Antrim

Questions about basement & cellar steels in Antrim

Who approves basement & cellar steels in Antrim?

Structural work in Antrim needs a full plans application or building notice to Antrim and Newtownabbey Borough Council. We prepare and submit it with the structural engineer's calculations and arrange the inspections, so the completion paperwork follows the job.

Can I stay at home while the work is done in Antrim?

Usually, yes. The work area is screened and floors are protected. The rooms either side of the opening are out of action for a few days, and there is some noise and dust while the masonry comes out.

How is steel protected from damp in a basement?

Steel below ground is protected against corrosion as the engineer specifies, which may mean a heavier-duty paint system or galvanising. It is also kept on the dry side of the waterproofing where possible, and fixings through the waterproofing are detailed so they do not let water in.

Do you do the underpinning for a basement?

Underpinning is specialist work, and we coordinate the steelwork with the underpinning contractor rather than carrying it out ourselves. The engineer designs the steel and the underpinning sequence together, so beams, columns and new foundations fit the order in which the walls are deepened.

Will columns be needed in my basement?

Quite often. Below ground there may be no suitable wall to support the end of a beam, so a column carries the load down to a foundation. The position can usually be agreed with you at design stage so the column sits within a wall line, a kitchen island or a storage area.

Do I need a party wall agreement for basement & cellar steels in Antrim?

There is no Party Wall Act in Northern Ireland. Your title deeds and the general law apply instead, so agree the work with your neighbour in writing before it starts.

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.