Builders > FAQs - MURUS EPS SIPs

Which foam type is better - Murus EPS foam or Murus Polyurethane foam?
Neither foam is necessarily better than the other; rather, each foam type has unique properties and may offer advantages in certain instances. The primary difference between the two is the density of the foam. EPS foam density is a nominal 1 pound per cubic foot, while Polyurethane density is 2.2 pounds per cubic foot. While Polyurethane SIPs provide a higher R-value per inch of thickness, EPS SIPs can be less expensive than Polyurethane SIPs, making them an affordable alternative to Polyurethane for the budget-conscious.

Why should I consider having my order factory pre-cut?
There are several reasons. Murus uses state-of-the-art precision CNC (Computer Numerical Control) equipment to cut your order accurately. Factory pre-cutting can markedly reduce installation labor, and greatly cut down on site construction scrap, saving disposal costs. Panel Pre-cut drawings are included as part of the Panel Pre-cutting service.

What does Murus need from me to get started on an order?
If you require Murus to figure your order, we’ll need a good set of architectural plans that include dimensions and elevations so we can estimate material quantities and service costs for you. Builder-specified orders will process more quickly.  Here's a list of what you'll need to supply to us:

Complete final dimensioned drawings, including

   Four (4) building elevations

   Floor plans - dimensioned

   Building cross-sections - dimensioned

   Complete structural and/or timber frame components

      - dimensioned

   Roof plan - dimensioned

   Window and door locations

   Window and door schedule listing rough opening

      sizes (unit dimensions alone are not acceptable)

Applicable Building Code and design loads (roof, floor,

      wind, snow, etc.)

Where should I send plans and documentation?

Send your plans and documentation to:

The Murus Company
PO Box 220 (for US Mail)
3234 Route 549 (for FedEx, UPS, etc.)
Mansfield, PA 16933

What is the average lead time on an order?
For Pre-cut Panel orders for standard OSB panels, plan on a minimum of six to eight weeks from the time Murus receives your signed order, deposit, and drawings. This time frame can vary, so check with your Murus representative for current lead times. Custom orders will take a minimum of two to three weeks longer.

Are there special storage considerations for the panels once they’re on site?
Murus SIPs are stacked in bundles and wrapped in heavy gauge black plastic prior to shipping. The plastic provides some protection; however, it is recommended that the SIPs be covered with proper protective tarping until ready for use. SIPs should be stored on level risers which elevate the panels high enough off the ground to create an air flow beneath the bundle. This will help inhibit ground moisture from condensing on the underside of the bundle. For extended storage of SIPs, Murus recommends placing the wrapped panel bundles in a fully enclosed structure that provides protection from exposure to wind, rain, moisture, and UV light. Do not stack bundles more than two high. For more information, refer to the Murus Panel Installation Manual.

How is wiring accomplished in Murus SIPs?
If ordered, Murus cuts horizontal electrical chase(s) into the panel cores in the center of the foam. Chases are typically located at standard horizontal heights for outlets, depending on how the panels are ordered. In some cases, you may have to do some pre-wiring before the panels are installed and during the installation process, but often the majority of the wiring can be accomplished after the panels are installed. For more information, refer to the Murus Panel Installation Manual.

How is plumbing accomplished in Murus SIPs?
Good building practices will keep plumbing out of exterior walls. Most SIP home designs incorporate plumbing into interior partition walls.

How are Murus EPS SIPs installed?
Where SIPs are load bearing, they are typically installed over a 2x plate that is attached to the sill or subfloor. The foam is removed from the bottom of the panel between the skins so the panel sits over the 2x and nails are driven through the skins into the 2x. Usually a double 2x top plate is installed in the same manner. There are many variations on these procedures. For more information, refer to the Murus Panel Installation Manual.

Is there an obvious bottom to a panel?
Yes. Factory pre-cut panels will have layout numbers written on the bottom of the exterior skin. For uncut wall panels, the wiring chases are usually near the panel bottom.

How do I cut the panels?
There are various tools and methods available. You'll find some options here:

SIP cutting tools

What about routing the panel edges?
Routing can be accomplished using either a hot wire cutting tool or with a mechanical panel router. The hot wire cutting tool or foam scoop is available from various sources, including Demand Products, Inc. in Alpharetta, GA. (800) 325-7540 Demand Products.You can also rent or purchase a Panel Router (a specialized power tool specifically designed for use on SIPs) from Murus. The panel router is a specially adapted tool and should not be mistaken for a traditional hand-held router. When just a little routing is required, a flat bar or the claw of a hammer works fairly well, followed by a putty knife or chisel to refine the rout.

Once installed, how long can the SIPs remain exposed to the elements?
Murus SIPs should be completely covered as quickly as possible upon installation with code approved weatherproof roofing, siding, and trim to prevent exposure of the OSB to the elements and to UV rays.

How are kitchen cabinets and other wall elements mounted?
Standard installation procedure of screwing the cabinets to the walls is usually acceptable, although you may want to use a few more screws. Excessively heavy items may require readily available specialty fasteners.

Do Murus SIPs require any other special considerations?
Murus SIPs essentially create an airtight, energy efficient building envelope. Mechanical ventilation is required in order to maintain acceptable humidity levels within a Murus structure. An air-to-air exchanger (often called a heat recovery ventilator (HRV) or an energy recovery ventilator (ERV)) is a mechanical device that draws fresh air from outside while simultaneously exhausting stale air from inside. During this process, the incoming fresh air is preheated or precooled with the outgoing stale air without allowing the two airstreams to mingle, thus recovering much of the heating or cooling energy from the stale air. Read more: Mechanical Ventilation

For technical questions or questions about a specific project, please give us a call: (800) 626-8787.

Murus Panel Installation Manual