Standard thicknesses for the EPS foam core of PorterSIPs are 3 5/8”,
5 5/8”. 7 3/8”, 9 3/8” and 11 3/8” These sizes allow for the use of standard dimensional lumber wherever required in the plans.

Panel lengths of 8’, 9’, 10’, 12’ and 16’ are common, however panels are available up to 8’ X 24’ or any size that can be cut from 8’ X 24’ or 4’ X 24’ sheet of Oriented Strand Board. Panels with custom angles and/or cut-outs are also available.

One important decision to be made is whether to have panels pre-cut at the factory or cut at the site. This decision depends upon the individual job, the panel shape and other factors. The best solution is often a combination of factory AND site cut panels. Typically, site-made cuts might be made at the last panel in a section of wall where the foundation dimensions and the dimensional tolerance in the panels’ width may vary. Onsite-cutting the last panel in a sequence allows for an exact fit. When large window openings and notches may affect the strength of a panel, it is often better to cut them on the site after they’re erected.

Pre-cut panels can be provided with a numbering system that relates to the position of the panels on the plan. In such a case the structure can be assembled like a pre-numbered jigsaw puzzle with the answers and instructions already provided.

There are two basic panel types of PORTER SIPs, Type A & C

Type "A” panels are basic structural panels having a 7/16” thick Oriented Strand Board (OSB) skin on both faces of the panel. Type "A” panel sizes range from 4’ X 8’ to 8” X 24’. Overall thicknesses can be 4 1/2”, 6 1/2”, 8 1/4”, 10 1/4” and 12 1/8”.  Type “A” panels combine structure and insulation economy and versatility and are the common commodity type.

Type “A” panels can carry loads in many directions when properly installed. They can withstand transverse, axial, racking, and combination loads within the load limits defined in the tables of NER 467.Type “A” panels require covering on both interior and exterior surfaces after installation as follows:

All major building codes require that the interior surface must be covered with 1/2” regular wallboard to act as a thermal barrier.

The exterior surface must be covered with a drainage plan and using weather resistant siding and roofing. The covering may include a layer of felt roofing or equivalent between the covering and the panel skin. See siding or roofing manufacturer’s recommendation, and best practices by SIPA.

Type “C” panels are structural panels with face sheathing that is equivalent to or exceeds the strength specification of 7/16” rated structural sheathing on one surface and 19/32’ Roseburg reverse board (RRB) and batten fir plywood on the opposite surface. These panels are used without sheathing for exterior walls. The RRB must be coated with a weather resistant coating. Rated structural sheathing meets or exceeds the requirements of NER-108 (7/16” Structural I, Exposure I. span index 24/16).