Roof Truss Timber Calculator 2026 — Wood Use & Cost

Structural timber use for a roof truss depends on the roof type and area. As a guide: gable roof approx. 0.045 m³/m², hip roof approx. 0.05 m³/m², pyramid roof approx. 0.055 m³/m². For a 150 m² gable roof the use is approx. 6.75 m³ of timber.

The price of structural timber (C24 pine/spruce) in Poland in 2026 is roughly PLN 1,200–1,800 per m³, depending on region and section. Kiln-dried and planed timber is more expensive. For a 150 m² truss (approx. 6.75 m³) the timber alone costs approx. PLN 8,000–12,000.

Carpentry labour for assembling a roof truss is roughly PLN 100–150/m² of roof area. For a 150 m² roof the labour cost is approx. PLN 18,000–22,500. The price depends on the complexity of the structure, crew availability and the region of Poland.

A gable truss (two slopes) is the simplest and cheapest — less timber and labour. A hip (multi-slope) truss has more slopes, valleys and ridges, which raises timber use by approx. 10–15% and increases labour cost. A pyramid roof (four slopes over a rectangle) is the most material-intensive.

The most common is C24 softwood (pine or spruce). It should be dried to 18–20% moisture and protected with anti-fungal and fire-retardant treatment. Glued laminated timber (KVH, BSH) is more expensive but more dimensionally stable and recommended for larger spans.

The calculator estimates the cost of structural timber and carpentry labour. It does not separately include the cost of impregnation (approx. PLN 15–30/m² of timber surface), battens and counter-battens under the covering, roof membrane or flashings. Add these for a full roof estimate.

Timber is bought and priced per m³ (cubic metre), while carpentry labour is usually per m² of roof area. That is why the calculator converts roof area into timber use in m³ and calculates labour directly from area. This split reflects market practice in Poland.

No. The roof slope area is larger than the building footprint, because the roof is inclined. The steeper the pitch, the larger the slope area. You should enter the actual roof slope area in the calculator, not the building footprint.

For a typical detached house with a 150 m² gable roof the total truss cost (timber + labour) is roughly PLN 26,000–34,000. For a hip or pyramid roof the cost rises by 10–20%. A full roof with covering and flashings costs 2–3 times more.

Yes. A roof truss is a structural element and should be designed by a certified structural engineer as part of the building design. DIY estimates (such as this calculator) serve only for preliminary budget planning — they do not replace the design and structural calculations.