Builders> FAQs - MURUS PUR SIPs
How is Murus Polyurethane different than other manufacturers’ foams?
The properties and characteristics of Murus Polyurethane are superior to Isocyanurate and Polyisocyanurate foams typically produced by other SIP manufacturers. Murus’ proprietary manufacturing method, Uniform Dispersion Molding (UDM) is key to creating Murus SIPs’ superior characteristics. Each panel is manufactured (molded) independently. Liquid foam is dispersed uniformly throughout the panel mold. The foam expands, exerting up to 14 psi of pressure which is contained by the mold. During the expansion and containment process, the foam permanently bonds to the panel skins. Each SIP is allowed to cure for 20 to 45 minutes, depending upon the desired SIP thickness. The spherical cells produced by the UDM method provide uniform foam density throughout the panel, thus giving the foam superior and uniform strength, unlike the elongated, rice-shaped cells produced by Isocyanurate and Polyisocyanurate foams which are typically produced on continuous lamination lines that run much faster. Murus’ UDM manufacturing takes a lot longer, but the quality of the panel is worth the wait.
Which foam type is better – Murus Polyurethane foam or Murus EPS foam?
Neither foam is necesarily 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 nominally 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 accurately cut your order. Factory pre-cutting can markedly reduce installation time, and greatly cut down on site construction scrap disposal. 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 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, plan on a minimum of six to eight weeks from the time Murus receives your signed order, deposit, and drawings for standard OSB panels. 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 can mold horizontal electrical chase(s) through the panels during the manufacturing process. These chases are centered in the foam and are typically 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 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 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.
Regarding the cam-locks, what if one gets broken?
The cams are not relied upon as a structural element, so a broken cam is not an issue. The cams are intended to assist in connecting and aligning the panels.
The cam wrench won’t go into the access hole. What do I do?
Try tapping the panel near the wrench with a hammer while slowly turning it. If this is unsuccessful it is usually not an issue, but we’d still like to hear about it so we can inform our production and quality control departments.
What if the cams refuse to lock?
Make sure the cam halves are lining up, and check the male cams to insure they’re working. If the problem persists and you’re still struggling, please call Murus. There may be a less obvious issue that we can help pinpoint.
How do I cut the panels?
There are various tools and methods available. You'll find some options here: SIP cutting tools
There’s a cam in the way of a cut I need to make.
If you are cutting across a panel, you can cut through a cam. If ripping an edge you can still cut through them, but it may prove simpler to just remove the cam beforehand with a claw hammer or crowbar.
What about routing the panel edges?
If the panels require a large amount of routing (removal of the foam from between the skins), you can 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 virtually 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.
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