Insulating sunroom decks in less time with SIPs

What are SIPs?

SIP is an acronym for Structural Insulated Panel. SIP’s are building panels that can be used to build walls, roofs, and floors. They come in many different sizes and thicknesses to provide the best combination of strength and insulation required for the task at hand.

Using SIPs to build a house

SIP facings are typically metal (aluminum or steel) or wood (OSB or plywood) but other materials are used as well. SIP’s are incredibly strong. They are made with two structural facings bonded to core material. This assembly is also referred to as a sandwich panel or stressed skin panel. The sandwich panel acts like an ‘I’ beam, where the faces carry the bending loads (compression and tension) and the core carries the shear loads.

Comparing SIP to Steel Beam

In this article, we discuss OSB SIPs with EPS (Expanded Polystyrene Cores). These cores are also referred to as foam cores. Our PanelCraft™ sunroom and patio cover panels are also SIP’s, albeit with aluminum facings with foam or honeycomb core.

Thermal Deck Panels for Sunrooms

OSB SIP panels used in construction are extremely efficient, carrying more load than conventional framing and weighing less while benefiting from increased insulation values compared to regular batt insulation. These reasons alone make SIP’s a good idea for your sunroom floor, but there are even more benefits. When framing a sunroom deck there is the issue of how to insulate it. Often a plywood sheet is installed on the bottom of the joists to keep batt insulation from falling out, and vapour barrier is installed between the upper plywood sheet and the joists. When insulating a conventionally framed sunroom floor you must pay attention to air leakage, vapour penetration, and proper filling of the cavity with insulation. OSB SIPs with EPS core do not have these concerns. The foam actually serves as a vapour barrier, the insulation is maximized throughout the entire thickness, and the solid foam core essentially eliminates any air leakage.

Craft-Bilt distributes Structural Insulated Panels made by Thermapan. Thermapan SIP’s are made in a factory-controlled environment and they have been extensively tested. The panels are always 4′ wide. Our stock panel lengths and thicknesses have been determined to meet the needs of common deck sizes, but other sizes are available. The foam core is recessed along the perimeter to allow for rim joists and splines between the panels. Panels can be easily cut on the job site if necessary, although the easiest method to recess the foam is with a hot wire tool.

Using SIP panels for sunroom floorUsing SIP panels for sunroom floorUsing SIP panels for sunroom floor






ThicknessLengthThermal Resistance
6½ inches8 feetR37.1
6½ inches10 feetR37.1
6½ inches12 feetR37.1
6½ inches16 feetrequires mid beamR37.1
8½ inches14 feetR48.8
10¼ inches16 feetspecial orderR62.1

Benefits of a SIP Sunroom Floor

  • Install your insulated decks in less time
  • No need for vapour barrier
  • Greater strength
  • Greater insulation values

Visit our Where-To -Buy page to find a contractor near you who can provide sunrooms made by Craft-Bilt.