Where XPS Foam Board Is Used in North American Manufacturing

Extruded polystyrene board is a hardware store material with a closed cell, no water uptake, and a price the small builder already knows; it is cut and glued into aluminum and small fiberglass boats far more often than any specification admits

Extruded polystyrene holds its R-value and compressive strength while wet, which is why it is the specification against foundation walls, under slabs, under inverted roof membranes, and in freezer floors; the closed extruded cell does not wick, and the board comes in 25 to 100 psi grades

XPS goes above the membrane in protected-membrane and vegetative roofs because polyiso cannot sit in water; a small, specified slice of the roof board market

XPS is the continuous insulation choice where the wall will see moisture or where the designer wants a board with no facer to delaminate; it is the residential CI default in cold climates and holds a share of commercial CI on the same NFPA 285 basis

Coated and unfaced XPS sheathing is the alternative where the builder wants a vapor-open assembly or expects the board to see water during construction; it is the incumbent in the northern tier and losing share to polyiso on R per dollar

XPS-core SIPs are sold for below-grade and high-moisture panels where EPS would wick; a small share and shrinking since the HFO reformulation raised XPS cost

Closed-cell XPS resists moisture and compression, so it wins below grade, under slabs, and in inverted roofs

Extruded polystyrene board is cut and bonded in as panel core where the geometry is flat and regular and pouring is not worth the tooling, which describes a lot of bus and vocational body panel work

XPS board skinned with hardboard or thermofoil-wrapped MDF face sheets makes a lightweight cabinet door at half the weight of solid MDF; the same board the wall uses, offcut-friendly, and it holds a screw with an insert

Extruded polystyrene board is the laminated wall on most towables: it comes in the 1.5 to 2 inch thicknesses that match the aluminum tube frame, holds a flat face under the pinch roller so the FRP skin does not telegraph, does not absorb water when the skin eventually leaks, and carries an R-value the sales sticker can quote; Foamular, Styrofoam, and GreenGuard board are cut to the frame cavity on the lamination line

XPS board across the roof trusses gives a walkable deck between the membrane and the ceiling panel and keeps its thickness under a rooftop air conditioner that weighs a hundred pounds; the same supplier and cut as the sidewall, which is why it wins

The slide-out box is the same XPS-cored sandwich as the sidewall at a smaller size, and it is where the core matters most: the edges carry the seal compression every time the room moves and a soft core lets the seal go slack and leak

XPS board in a laminated floor deck between a wood or thermoplastic composite top and a corrugated or Darco underbelly sheet insulates from road temperature and holds up to point loads from slide rollers and furniture feet

Extruded polystyrene board as a lightweight core in stacking walls and demountable partitions, where the panel has to be carried and set by one installer and the acoustic duty is modest; stiffness per pound is the whole argument