Brick and Block Wall Self-Weight (kN/m² Table)

Brick and block wall self-weight in kN/m² by thickness and stated density, from 0.6 kN/m² for aircrete to 4.3 kN/m² for 215 mm dense block.

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A 100 mm masonry leaf weighs anywhere from about 0.6 kN/m² (aircrete) to 2.0 kN/m² (dense concrete block), and a 215 mm solid brick wall about 4.1 kN/m². Self-weight is simply thickness × density, so the answer depends on the density. A typical plastered brick and block cavity wall comes to roughly 3.6 kN/m² of elevation.

Published figures for "the same wall" run from under 2 to over 4.5 kN/m² because the source rarely says which density it assumed. This page states the density behind every number, so you can see why two answers differ and pick the one that matches your product.

What does a brick or block wall weigh per m²?

Self-weight in kN/m² of wall face is thickness (m) × density (kN/m³). The table uses typical densities for the wall as built (units plus mortar joints). The three block densities are examples within a wide range: check the manufacturer's data for the block you are actually specifying.

These are bare masonry with no plaster, render or finishes. Typical values: they must be checked by a competent engineer for design.

Why do published values disagree?

Because the density behind them is rarely stated. The densities in the table are typical, but real products span a wide range:

• Aircrete (autoclaved aerated concrete): about 4 to 8 kN/m³ depending on strength grade. Standard grades sit around 6.
• Medium dense concrete block: about 12 to 16 kN/m³, often with lightweight aggregate.
• Dense concrete block: about 19 to 22 kN/m³. Solid dense blocks can be heavier than the 20 used above.
• Clay brick: about 17 to 21 kN/m³ for the wall as built. Perforated and lightweight units are lighter.

So a 215 mm solid brick wall is 3.7 kN/m² at 17 kN/m³ and 4.5 kN/m² at 21 kN/m³. Both are "correct" for their product. A 100 mm leaf can be anywhere from 0.6 to over 2 kN/m² depending on the block, which is a factor of three.

If you do not know the product yet, take a sensible middle value and say so on the calculation. If the block choice might change later, say which way you have erred.

How much does a cavity wall weigh?

For a cavity wall, add the leaves and ignore the cavity (wall ties and insulation are negligible next to the masonry). Plaster and render are included in the right-hand column below, using the allowances in the next section.

The brick and 100 mm medium dense block wall at 3.6 kN/m² is the usual starting point for a two-storey house. It agrees with the "about 3.5 kN/m²" rule of thumb in the manual load takedown article.

What allowance for plaster and render?

Finishes are small next to the masonry but not nothing. These are round allowances, based on the thickness and a typical density for each finish:

Wet plaster allowances vary a little with the mix, so 0.25 is a round figure that errs slightly high. Add the allowance for each face that actually has the finish. A wall with plaster on one side only gets one allowance. Brickwork left as exposed face on both sides gets none.

How do I convert kN/m² to kN/m on a wall line?

A load takedown works in kN/m along the wall, because the foundation is a strip. Multiply the area weight by the height of wall it represents:

Wall line load (kN/m) = self-weight (kN/m²) × wall height (m)

The height is normally the storey height, floor to floor, because that is the wall that sits on the element below. Keep the same convention at every level so nothing is counted twice or dropped.

For a first-pass takedown you can ignore openings and take the full height. That is conservative and quick. For a more economical result, deduct openings: take the net wall area (gross area less windows and doors), multiply by kN/m², then divide by the wall length to get an average kN/m. Remember the load above an opening does not vanish, it goes into the lintel and then into the masonry either side. If you average along the whole wall you are smearing it, which is fine for a strip foundation but wrong for a pier. The foundation loads from a wall article shows how the wall load is carried down to the footing.

Worked example: 2.4 m storey of cavity wall

Take a ground floor external wall: 102.5 mm brick, 100 mm medium dense block, plastered inside. From the table, 3.6 kN/m².

Solid length, no openings. Storey height 2.4 m:

3.6 × 2.4 = 8.6 kN/m

Same wall, 4.0 m long with a 1.2 m × 1.2 m window.

• Gross area: 4.0 × 2.4 = 9.6 m²
• Window: 1.2 × 1.2 = 1.44 m²
• Net area: 8.16 m²
• Total weight: 8.16 × 3.6 = 29.4 kN
• Average over 4.0 m: 29.4 / 4.0 = 7.3 kN/m

So deducting the opening saves about 15 per cent on that wall. The glazing weighs something too (a few tenths of a kN/m²), but over 1.44 m² it adds roughly 0.5 kN, which is lost in the rounding.

On a real job this 8.6 kN/m is the masonry self-weight at that level only. You then add it to the floor and roof reactions, then pick up the wall above in the same way. The worked example takes a full two-storey house through that process.

Where do these densities come from?

There are two sources, and you need both:

• BS EN 1991-1-1, Annex A. It gives nominal densities for building materials, including masonry units and mortar, as ranges by material. Use it when you have no product data. It is also the reference to cite on a calculation sheet.
• Manufacturer data sheets. Block and brick suppliers publish the dry density of each product, and often the mass of a finished wall in kg/m². Multiply kg/m² by 0.00981 to get kN/m². For a known product this is better than any generic table.

Plaster and render allowances are standard UK practice rather than code values. Check them against the product if the finish is unusual (thick insulated render, for example).

Two practical points. Moisture adds a little weight, which the nominal densities already cover. And a wall that is partly filled, for example with concrete in cavity foundations or solid cores, is a different build-up: calculate it separately.

FAQ

What is the self-weight of a brick wall in kN/m²?

A 102.5 mm clay brick leaf is about 1.95 kN/m² at 19 kN/m³, and a 215 mm solid brick wall is about 4.1 kN/m². The usual range for clay brickwork is 17 to 21 kN/m³, so a 215 mm wall can be anywhere from about 3.7 to 4.5 kN/m². Check the brick supplier's density.

What is the weight of a 100 mm block wall per m²?

It depends on the block: about 0.6 kN/m² for aircrete at 6 kN/m³, 1.4 kN/m² for medium dense concrete at 14 kN/m³, and 2.0 kN/m² for dense concrete at 20 kN/m³. Add roughly 0.25 kN/m² for each plastered face. Use the manufacturer's data once the block is chosen.

What is the weight of a 225 mm brick wall in kN/m?

A nominal 225 mm wall at 19 kN/m³ is about 4.3 kN/m², so about 10.3 kN/m over a 2.4 m storey (4.3 × 2.4). Most solid brick walls are actually 215 mm, which gives about 4.1 kN/m² or 9.8 kN/m per 2.4 m. Always multiply by the real wall height.

Should I deduct openings from wall self-weight?

For a quick takedown you can leave them in, which is conservative. For a tighter result, deduct window and door areas and average the load over the wall length. Do not do that for a pier or short length of wall beside an opening, because the load above the opening is carried there. Calculate those separately.

Is block density the same as block weight?

No. Density is in kN/m³ (or kg/m³) and is what you multiply by thickness. Suppliers often quote the weight of a single block in kg. To convert to a wall, divide by the block's face area to get kg/m² of wall, or use the dry density directly. Make sure you know which figure you are looking at.

Do the whole building in LoadTakedown: pick the wall type once and the self-weight is carried through every level automatically. For a free starting point, there is also a spreadsheet template.