Beam

What is a beam in a family house?

A beam is a horizontal structural member that carries loads across a gap and passes them to supports at its ends. In a family house the word covers three groups of members. The first is the short beam over a door or window opening, the preklad, which is a lintel in English. The second is the longer beam that spans a room or takes over from a removed wall. Builders make it from steel, timber or reinforced concrete. The third is the concrete band around a masonry wall, known as a ring beam or stužujúci veniec. The Slovak word nosník covers all of them, and designers name each member by where it sits and what it carries.

How does a beam carry its load?

A beam carries load by bending between its supports. The load reaches it from the joists, slabs or rafters that bear on it, and the beam passes that load to its two ends. In a reinforced concrete beam the designer measures the effective depth d from the most compressed fibre to the centre of the tensile force. See JRC Eurocode 2 worked examples, section 1.5.1.1.

A beam must also stay stiff enough. For concrete beams and slabs Eurocode 2 gives a deemed-to-satisfy rule for deflection. It limits the ratio of the effective span to the effective depth d, so a longer span needs a deeper section. The permitted ratio depends on the support conditions and on the reinforcement. The engineer reads it from the code, not from a rule of thumb (JRC worked examples, section 1.5.1.1, citing Eurocode 2 clause 7.4.2).

The ends matter as much as the section. Each support must take the reaction of the beam, and the structure below must carry it down to the foundation. The designer of the static part answers for this under Building Act 25/2025 § 9 ods. 8, and the static calculation must be verifiable.

Which materials are beams made from?

Reinforced concrete, steel and timber cover most beams in Slovak houses. Timber beams are either solid timber or glued laminated timber (glulam). The table gives what the sources say about each material.

Beam type	Typical use in a house	What the sources say	Main constraint
Reinforced concrete	Floor and roof edges, beams over wide openings, ring beams	Eurocode 2 sets the minimum concrete cover over the reinforcement by exposure class, and EN 1992-1-2 covers fire design	The cover must stay intact so the steel stays protected
Steel I-section	Long spans, opening up a wall in an existing house	Exposed steel weakens at high temperatures, so protection materials insulate it for the required fire resistance period	Corrosion needs moisture and oxygen. In a dry heated interior the risk is insignificant
Glued laminated timber (glulam)	Exposed beams in timber houses and open-plan rooms	EN 1995 covers glued laminated timber along with solid and sawn timber	Fungal decay needs a moisture content of about 20 % to 60 %, so keep the beam dry
Solid timber	Ceiling and roof beams in traditional and timber houses	EN 1995 covers solid and sawn timber	The same moisture limit applies as for glulam

The structural designer chooses the material. The same opening in steel or in glulam needs a different section, connection and protection. Changing material late is rarely a small change.

How does a beam replace a load-bearing wall?

A load-bearing wall removal moves the wall's job onto a beam. The beam collects the floor or roof load that the wall carried and passes it to new supports at its ends. Those supports are usually new columns or enlarged sections of the remaining walls. The beam is only part of the solution, because the design must also show where every load goes and that the foundations can take it.

Until the beam and its supports take over, the wall carries that load. Design the beam before anyone opens the wall. A structural engineer decides after inspection whether a wall is load-bearing, because appearance, thickness and position do not settle the question.

How is a beam different from a lintel?

A lintel is a short beam over a single opening in a wall. It spans the opening and passes the load above it to the wall on each side. A beam is usually longer and carries floor or roof loads across a room or a removed wall. Both are structural members that need design. The difference lies in span, load and support, not in whether a calculation is needed.

Feature	Lintel (preklad)	Beam (nosník)
Position	Over a door or window opening	Across a room or a removed wall
What it carries	The load above the opening	Floor or roof loads, and any wall above it
Supports	The wall on each side of the opening	Walls or columns at both ends

Who designs a beam and which rules apply?

Only the Eurocodes apply to designing building structures in Slovakia from April 2010, according to the standards office ÚNMS. EN 1992 covers concrete, EN 1993 steel and EN 1995 timber, so the engineer checks a beam against the part that matches its material.

Act 138/1992 § 5 ods. 4 lists the design of load-bearing structures among the services of an authorised engineer for building statics (inžinier pre statiku stavieb). Building Act 25/2025 § 9 ods. 8 makes the designer of the static part answer for the load-bearing structures.

The Building Act also sets the permit side. Under § 18 ods. 2, a change of a completed building needs a decision on building intent, unless the act says otherwise. Under § 18 ods. 3 písm. h), an alteration needs notification when the works may endanger mechanical resistance and stability. The exemption for repair and replacement covers only non-essential structural elements such as interior partitions (§ 18 ods. 5 písm. a) bod 2). A beam is a load-bearing element, so this exemption does not cover it.

The execution design is a detailed elaboration of the verified building project (§ 9 ods. 5). The act makes it compulsory for a reserved building (vyhradená stavba). Draw the beam and its supports in the documentation before the wall comes out.

What should be checked before a beam goes in?

Before the crew sets the beam, check these points on site and against the design:

• The bearing at each end matches the drawing, and the material there is sound.
• The designer sized the supports below each end, including the foundations, for the new reactions.
• Steel has the fire and corrosion protection that the design specifies.
• Timber stays dry from delivery to installation.
• The as-built documentation shows the beam, its connections and its supports. Under § 10 ods. 4 of the Building Act this documentation is a basis for final approval (kolaudácia).