Eurocode 6 Masonry Wall Design Calculator (EN 1996-1-1)

Check unreinforced masonry walls in compression to Eurocode 6: vertical resistance, slenderness, eccentricity and utilisation.

Eurocode 6 Masonry Wall Design

1. Masonry material

N/mm²

If unknown, estimate from unit and mortar using EN 1996-1-1 Table 3.3 / NA.

–

Check value in your National Annex (typ. 2.0–2.7).

2. Wall geometry & supports

mm
mm
mm

Effective height per EN 1996-1-1 5.5.1 / NA.

3. Axial load & eccentricity

kN
mm
mm
mm

Often taken as t/20 or 20 mm, whichever is greater (check NA).

Eurocode 6 masonry wall design – theory and formulas

This calculator helps you check an unreinforced masonry wall in compression according to Eurocode 6 – EN 1996-1-1. It focuses on vertical resistance of walls subject to axial load with eccentricity, including the effects of slenderness.

1. Design compressive strength of masonry

The characteristic compressive strength of masonry fk is usually obtained from EN 1996-1-1 Table 3.3 (or the National Annex) based on unit and mortar strength, or from tests / manufacturer data.

Design compressive strength:

$$ f_d = \frac{f_k}{\gamma_M} $$

where:

  • \( f_k \) = characteristic compressive strength of masonry (N/mm²)
  • \( \gamma_M \) = partial factor for masonry (typically 2.0–2.7)
  • \( f_d \) = design compressive strength (N/mm²)

2. Effective height, thickness and slenderness

The effective height \( h_\text{eff} \) depends on the support conditions at top and bottom (clamped, pinned, cantilever, etc.) as defined in EN 1996-1-1 5.5.1 and the National Annex. This tool uses typical factors:

  • Fixed–fixed: \( h_\text{eff} = 0.75 h \)
  • Pinned–pinned: \( h_\text{eff} = h \)
  • Cantilever: \( h_\text{eff} = 2 h \)

For a single-leaf wall, the effective thickness is usually equal to the actual thickness \( t \).

Slenderness ratio:

$$ \lambda = \frac{h_\text{eff}}{t_\text{eff}} $$

Eurocode 6 limits the slenderness of walls (e.g. \( \lambda \leq 27 \) for many cases, but check the National Annex and specific clauses for your wall type and loading).

3. Eccentricity and minimum eccentricity

Masonry walls are rarely loaded in perfect axial compression. Eurocode 6 accounts for eccentricity of the axial load at the top and bottom of the wall.

The design eccentricity at mid-height is often taken as:

$$ e_m = \max\left( \frac{e_t + e_b}{2},\ e_\text{min} \right) $$

where:

  • \( e_t, e_b \) = eccentricity at top and bottom
  • \( e_\text{min} \) = minimum eccentricity (e.g. \( t/20 \) or 20 mm, whichever is greater)

4. Reduction factor for slenderness and eccentricity

The design compressive resistance of a slender wall is reduced by a factor \( \phi \) that accounts for second-order effects and eccentricity. Eurocode 6 provides several methods. This calculator uses a simplified interaction:

$$ \phi = \left( 1 - \alpha \left( \frac{\lambda}{\lambda_\text{lim}} \right)^2 \right) \left( 1 - \beta \frac{e_m}{t/2} \right) $$

with \( \phi \) limited to the range 0 < \( \phi \) ≤ 1.

Here \( \lambda_\text{lim} \), \( \alpha \) and \( \beta \) are calibration parameters chosen to give conservative results compared with the full Eurocode 6 interaction curves. They are not a substitute for the exact code expressions and should be used for preliminary checks only.

5. Design compressive resistance of the wall

The design compressive resistance of the wall is then:

$$ N_\text{Rd} = \phi \, f_d \, A $$

where:

  • \( A = t \times l \) = cross-sectional area of the wall (mm²)
  • \( f_d \) = design compressive strength (N/mm²)
  • \( \phi \) = reduction factor (slenderness & eccentricity)

The wall is adequate in compression if:

$$ \eta = \frac{N_\text{Ed}}{N_\text{Rd}} \leq 1.0 $$

6. Limitations and scope

  • Unreinforced masonry walls in compression only.
  • No check of in-plane shear, out-of-plane bending, concentrated loads or openings.
  • No fire, robustness, or detailed detailing checks.
  • National Annex parameters (γM, emin, slenderness limits) must be verified.

For final design, always refer to the full text of EN 1996-1-1, EN 1996-1-2 and the relevant National Annex, and have calculations checked by a qualified structural engineer.

Frequently asked questions

What inputs do I need for Eurocode 6 masonry wall design?

You need the characteristic compressive strength of masonry \( f_k \), the partial factor \( \gamma_M \), wall thickness and height, support conditions, design axial load \( N_\text{Ed} \), and the eccentricities at top and bottom (or a minimum eccentricity).

How do I get the characteristic compressive strength fk?

Use EN 1996-1-1 Table 3.3 (or your National Annex) based on unit strength and mortar class, or use tested values or manufacturer data. Many brick and block suppliers provide fk values for their products.

What is a typical partial factor γM for masonry?

A common value is γM = 2.0 for masonry in buildings, but some National Annexes specify 2.3 or 2.7 depending on the execution control class and material. Always check the National Annex for your country.

Can I use this calculator for reinforced masonry?

No. Reinforced masonry design requires additional checks for reinforcement, bond, cracking, and interaction of axial load and bending that are not included here.

Is second-order (P–Δ) effect fully covered?

The calculator includes a simplified reduction factor for slenderness and eccentricity. For very slender walls or high utilisation, a more rigorous second-order analysis in accordance with Eurocode 6 should be performed.