- A wall running perpendicular to the floor span is the most likely to carry load.
- Deflection, not strength, usually determines the steel section — especially with masonry above.
- The bearing at each end is where things go wrong, not the beam.
- Load that was spread along a wall now lands on two points and must reach the foundation.
- Changing the structure means a permit for the technical building activity in almost every case.
"Can this wall come out?" is the question we are asked most often. Usually the answer is yes, but the interesting part is what has to happen for it to be a good idea. This guide explains how to recognise a structural wall, what the engineer actually calculates and where the risk really sits.
Recognising a load-bearing wall
| Indicator | What it suggests | Reliability |
|---|---|---|
| Archive drawings from the municipality | Definitive answer | Highest |
| Runs perpendicular to the floor beams or slab span | Likely load-bearing | High |
| Continues on the floor above and below | Likely load-bearing | High |
| Solid masonry rather than a light partition | Possible | Medium |
| Noticeably thicker than other internal walls | Possible | Medium |
| Sounds solid rather than hollow | Possible | Low |
Thickness alone proves nothing: plenty of thick walls carry no load, and some slim ones carry a great deal. Get it established rather than inferred.
In a typical Dutch terrace the party walls carry the floors, and the floor beams span between them. Internal walls running the same direction as those beams often carry nothing; walls crossing them usually do. But there are exceptions in every era, particularly in pre-war houses that have been altered.
What the structural engineer calculates
- Load take-down. Which floors, walls and roof elements transfer load onto this wall, and over what width. The direction of the floor span is decisive.
- Permanent and variable load. The self-weight of the structure against the changing load of occupants and furniture, each with its own safety factor.
- The beam section. Which steel profile can span the opening without failing.
- Deflection. Usually the governing criterion. A beam can be strong enough and still sag by a few millimetres, and masonry above the opening cracks at very small movements, so a stricter deflection limit applies there.
- The bearing. How the beam sits on the remaining masonry at each end, over what length, and whether a spreader plate is needed.
- The route downwards. Load previously spread along the whole wall now concentrates at two points. It has to reach the foundation.
That final item is the one most often skipped in a cheap calculation, and it is the one that matters most in a pre-war house on timber piles.
Required steel rises disproportionately with span, because deflection governs. Widening an opening by half a metre does not add ten per cent of steel; it can add considerably more. That is why the opening width has to be fixed before the calculation.
The beam and its bearing
Steel dominates because of height. Above an opening in an existing house there is rarely more than twenty or thirty centimetres before you meet the floor structure above. Steel offers the most capacity per centimetre of depth, which is exactly the constraint. Timber would work but needs far more depth; a precast concrete lintel is fine for small openings and inadequate for large ones.
Where things actually go wrong is the bearing:
- Too short a bearing length, concentrating load on too small an area of masonry.
- No load spreading where the masonry requires a plate or a padstone.
- Poor masonry beneath the bearing — old, soft or previously cut.
- An incomplete mortar bed, so the beam sits on high points rather than the full area.
- Not level, distributing load unevenly and pulling the finishes over time.
Ask your contractor how the bearing will be formed and over what length. Someone who answers immediately and specifically has read the drawing. That is a better signal than any quotation.
Propping and getting the steel in
Propping. Before a brick is removed, the load above must be supported: adjustable steel props on both sides of the wall, on a firm base, with a spreader beam so no single floor joist takes everything. Props on a floating screed or a tiled floor with a void beneath will sink, and then they are doing nothing. Almost every serious incident in this kind of work happens at this stage, not at the beam.
Access. A four-metre steel beam is heavy and does not bend. In a Rotterdam terrace with a turn in the hallway, or an upper-floor apartment, this is a real constraint. Routes used in practice: through the hallway if the turns allow, through a temporarily removed window with a hoist, through a straight stairwell, or in two lighter sections spliced on site — which must be designed that way in advance.
In an apartment, the owners' association also has to approve the change, because the structure is communal.
Full opening, partial opening or wide doorway
| Option | What it gives | Structural impact | Best for |
|---|---|---|---|
| Full opening | Maximum openness, one space | Heaviest: longest span, heaviest section | Genuinely using both rooms as one |
| Opening with a pier retained | Almost the same effect, natural zoning | Considerably lighter | Most Dutch terraces, most of the time |
| Wide doorway | Connection without merging | Light: short beam, simple bearing | Keeping acoustic and thermal separation |
| Moving the wall | A genuinely different plan | Heaviest and most complex: new load path | Full reconfiguration when floors are open anyway |
The middle option is the one most often overlooked, and in a narrow Dutch terrace it usually gives the best result per unit of intervention.
Practical point that only becomes obvious after the furniture arrives: a fully opened ground floor leaves very little wall to put anything against. A retained pier gives you somewhere for a tall cupboard, a television or the services you would otherwise have to reroute.
Permit, timeline and what to keep
Changing the load-bearing structure requires a permit for the technical building activity in almost all cases, regardless of how small the opening is. A doorway in a structural wall is a structural change just as a four-metre opening is; the beam is lighter and the procedure identical.
Realistic sequence: establish the structure and obtain archive drawings (days to weeks), fix the opening dimensions, structural calculation (weeks), permit application (eight weeks, extendable), then propping, demolition, beam installation and bearings (days), and finishing with drying time (weeks).
Keep afterwards: the calculation, the drawings, the permit, and photographs of the bearings before they are closed up. Those photographs cannot be taken later and they are the most valuable document in the file at resale.
Summary
A wall crossing the floor span, continuing above and below, is probably structural — but get it established from the archive drawings rather than inferred from thickness. The engineer sizes the beam mainly on deflection, not strength, which is why widening an opening costs disproportionately more. The real risk sits in the bearing at each end and in the load path down to the foundation, particularly in a pre-war house on timber piles. Consider retaining a pier: lighter structurally, easier to get through the process, and it leaves you wall space. And photograph the bearings before anything is closed up.
Next: foundations or renovation permits.