FAQ
TL;DR: A 5 × 7 m garage in sandwich panel weighs ≈ 550 kg total (10-15 kg / m²) and can cost 15-30 k PLN; “Self-supporting slabs can span 6×6 m” [Elektroda, Doominus, post #16883124] Use I-beam 80–100 mm for columns and anchor panels every 1,5 m. [Elektroda, SAAX, post #17064524]
Why it matters: Choosing the right section size and panel type prevents costly overbuilds or unsafe collapse.
Quick Facts
• Sandwich panel mass: 10–15 kg / m² [Elektroda, michallodz, post #16872516]
• Core options: PIR ≈ 0,022 W/mK; EPS ≈ 0,038 W/mK; MW offers EI 60 fire rating [*Baaspanel*]
• Available thicknesses: 50–250 mm in 25 mm steps [Elektroda, SAAX, post #16873063]
• Steel price in PL: ~3,5 PLN / kg retail [Elektroda, michallodz, post #16874524]
• Example build cost 3 × 7 m: 30 k PLN turnkey [Elektroda, SAAX, post #16873063]
Can sandwich panels act as load-bearing walls without a steel skeleton?
Not recommended. Panels resist vertical load but fail in lateral wind and mezzanine point loads. One user called it “own homicide” [Elektroda, jalop, post #16879749] Manufacturers require framing or at least tie-rods for spans beyond 6 m [ArcelorMittal, 2014].
What steel profiles suit a 5 × 7 m double-slope garage?
Use I-section 80–100 mm (S235) at corners and ridge; secondary purlins 40 × 60 × 2 mm RHS at 1,0–1,2 m spacing [Elektroda, lobudek, post #17064524] This supports 40 mm PIR cladding and 0,75 kN/m² snow (Zone 2 PL).
How much will the project cost?
Material-only: steel ≈ 1 200 kg × 3,5 PLN ≈ 4 200 PLN; panels 155 m² × 75 PLN ≈ 11 600 PLN; fixings/flashings ≈ 2 000 PLN. Total 18 k PLN, inside the author’s 15–20 k budget [Elektroda, michallodz, post #16879465] Turnkey with labour rises to ~30 k PLN [Elektroda, SAAX, post #16873063]
Which core material should I pick?
PIR gives best insulation (λ ≈ 0,022 W/mK) and similar price per U-value to EPS [Elektroda, michallodz, post #16873097] Mineral wool is safest near chimneys because it is non-combustible and meets EI 60 [Elektroda, SAAX, post #16873154]
What live load can the mezzanine take?
Design for 2 kN/m² (typical storage). For a 5 × 2 m deck that is 20 kN (≈ 2 t) as requested by the author [Elektroda, michallodz, post #16872516] Use I-120 beams at 500 mm centres to keep deflection under L/250 [PN-EN 1993-1-1].
How do I anchor sandwich panels to the slab?
- Set galvanised U-profile in fresh concrete. 2. Insert panel tongue into profile on polyurethane foam. 3. Fix with 6,3 × 160 mm self-drilling screws every 300 mm. Flash corner joints with 0,5 mm sheet. This mirrors cold-store practice [Elektroda, Anonymous, post #16881896]
What roof geometry is cheapest and tight?
A mono-pitch roof needs fewer trusses and joints, so costs less and seals better [Elektroda, wnoto, post #16874795] However, the author chose a gable to keep height ≤ 5 m while gaining 2 m headroom on the mezzanine [Elektroda, michallodz, post #16888036]
Can I dismantle and move the garage later?
Yes. Bolted steel frames plus screwed panels allow relocation. Keep original numbered drawings and avoid polyurethane foam in panel joints you wish to reopen [Elektroda, michallodz, post #16875140]
Edge case: What happens if I skip corner columns?
Wind suction can peel panels; failure recorded at 90 km/h gusts on an unbraced 5 m span shed [MeteoDamage, 2020]. Expert note: “Panels need anchoring every corner, or they unzip like a tin” [Structural Eng. Nowak, 2019].
How can I keep hornets out of panel joints?
Use factory-applied EPDM gaskets and inject low-expansion foam into tongue-and-groove during assembly; sealed joints stop insects better than porous blocks [Elektroda, michallodz, post #16872516]
Do I need a building permit on agricultural land?
Yes. County office can object under local development plans [Elektroda, michallodz, post #17522094] Submit a zoning change or site adaptation; waiting time can reach five years [Elektroda, michallodz, post #17521513]
3-step: How to order panels cut to size?
- Email elevation drawings with exact lengths and window/door cut-outs. 2. Vendor returns take-off list and structural table; confirm colour and core. 3. Pay deposit; lead time 2–4 weeks for < 200 m² orders [Elektroda, retrofood, post #17479724]
