Studio Matrx Monthly · Volume 1 · Issue 1 · June 2026
Amogh N P
 In loving memory of Amogh N P — Architect · Designer · Visionary 
Door Gap Foam Calculator

Door Gap Foam Calculator

Enter the frame perimeter (or a door size), the packing-gap width and how many doors — and get the PU foam cans, sealant tubes and all-in material cost with 18% GST. Indicative India 2026 figures; always confirm on site.

Your gap

Gap run ≈ 2 jambs + head (5.1 m per door). One 750ml PU foam can fills ~2-3 door perimeters at a 10mm gap; coverage drops as the gap widens. Sealant is the optional finishing bead over the foam. Indicative India 2026 — varies by brand and site.

PU foam cans needed (750ml)

0 can

1 door · 5.1 m of gap · 708 material (incl. GST)

Foam cans

1

750ml each

Sealant tubes

1

cartridges

All-in cost

₹708

material

  • Foam380
  • Sealant220
  • GST108

Material cost split. Indicative — confirm with your fitter and brand.

How the gap width changes the foam you need

Cans of 750ml PU foam for 5.1 m of total gap (1 door) at different gap widths. Your gap width is highlighted — wider gaps burn through foam faster, so pack with timber slips first.

Get the sealing detail right

DesignAI advises on foam vs grout, acrylic caulk vs silicone, and the damp-proofing detail at the frame base — and sense-checks your material list.

Assumptions & notes

  • • Coverage benchmark: one 750ml PU expanding-foam can fills about 2-3 door-frame perimeters (≈ 12.5 m of a 10mm gap); a 900 × 2100 frame is ~5 m of gap run.
  • • Foam more than doubles in volume — overfill is wasteful and bows the frame. Pack gaps over ~12mm with timber slips first, then foam in light beads.
  • • Sealant is the optional finishing bead: acrylic caulk internally, silicone for external/wet joints. Foam must be trimmed and covered, never left exposed to sun.
  • • The frame must be set plumb, level and square before foaming — foam holds, it does not align. In India add a DPC / anti-termite detail at the frame base.
  • • Costs are material only and include 18% GST where shown; they exclude labour, packers and architrave. Rates are indicative India 2026 and vary by brand and city.
  • Indicative only — confirm with your carpenter/fitter on site; measure twice, foam once.