Thermapan FAQ
13 Frequently Asked Questions about SIPs

1. HOW MUCH DOES A SIP WEIGH?
A 4x8x4½" SIP weighs about 100 lbs. Refer to our Weight Tables (12k pdf) for the exact weight of different panel sizes.

2. ARE THE PANELS STRUCTURAL?
Yes. And tests indicate Thermapan SIPs are significantly stronger than conventional 2x4 or 2x6 walls.In fact, houses built with Thermapan SIPs have withstood the force of Class 6 hurricanes, such as Andrew, Hugo and Mitch.

3. WHAT IS THE R-VALUE OF A SIP?
The 4½" inch thick SIP has a rating of R-20. However, it is important to note that SIPs are much more efficient than conventional types of insulation with the same R-Value. A home built with SIPs will use about 25% less energy than a typical stick-framed house. The solid, air-tight construction of these panels is what gives them their superior thermal performance.

4. DO SIPs NEED A VAPOUR BARRIER?
No, as long as the panel joints and connections are protected against moisture exfiltration as detailed in Thermapan's installation manual, a vapour barrier is not needed.

5. HOW MUCH DO SIPs COST COMPARED WITH TRADITIONAL STICK FRAMING?
As a rule of thumb, SIPs add approximately 1% to the overall cost of a home built with traditional building materials. However, the resulting energy savings of the Thermapan system can quickly make up the difference. Due to ease of installation, SIPs also dramatically reduce framing labour costs.

6. DO SIPs COME PRE-FRAMED WITH WINDOWS AND DOORS?
No. Thermapan SIPs use a standard system that makes them easy to assemble and extremely cost effective. One of the key benefits of the Thermapan system is its design flexibility. SIPs can work with any number of window and door combinations. Thermapan's reference manual also makes the installation of windows and doors straightforward and simple. Or watch our short Door & Window Openings Installation Video and see how easy it really is.

7. WHAT TOOLS DO I NEED TO INSTALL SIPs?
You will need regular carpentry tools plus a hot knife and expanding foam. A hot knife is a tool for holing out grooves in the EPS, and is needed whenever SIPs must be cut to size. Hot knives are easy to use and can be purchased or rented from Thermapan. Expanding foam is used to seal all connections between individual SIPs and top and bottom plates thus ensuring the structural integrity of the system. For a full list of SIP tools that Thermapan can supply, visit our Accessories page.

8. HOW DO YOU INSTALL WIRING?
Thermapan SIPs are both simple and easy for electricians to wire. Two 1½" diameter horizontal wiring chases at 12" and 18" are standard in all wall panels. These chases can be easily accessed from interior partition walls or from beneath the floor deck. Visit our Installation Photos page for some detailed shots of electrical installation.

9. HOW DO THERMAPAN PANELS CONNECT?
SIPs are fastened over a bottom plate and connected at the sides with EPS splines that are supplied with the Thermapan system. Two top plates are fastened to complete the process. Thermapan offers a complimentary reference manual covering all major installation details such as walls, floors, roofs and foundations. Our series of Installation Videos also demonstrate a wide range of connections for different Thermapan SIP applications.

10. HOW DO I FINISH SIPs?
You can do this by siding or straping the SIP walls directly. A moisture membrane is needed on the outside of the panel. After that, it's just a matter of following the installation details from the siding or finishing manufacturer. Thermapan offers a line of SIPs with pre-finished wood siding, replacing one of the oriented strand board (OSB) sides. Thermapan roof panels can also be finished with any standard material such as shingles or metal roofing.

11. WHAT IS THE FIRE RATING OF A SIP?
With 1/2" gypsum board, SIPs have a 15-minute fire rating which meet residential fire code regulations. Thermapan SIPs also meet the National Building Code of Canada. As with any fire resistance issue, however, requirements vary by region, occupancy and building classification. You should contact your local building or fire departments to determine the necessary requirements and ensure compliance with local fire codes.

12. DO SIPs CONTAIN FORMALDEHYDE ?
The answer to this question is while technically yes, effectively they do not. This is because the amount of formaldehyde emitted by the oriented strand board (OSB) used in SIPs is less than 0.1 PPM (parts per million). This is well below accepted levels established by the U.S. Department of Housing and Urban Development (HUD). Additional details and test results can be found in this Technical Document.

13. WHAT IS THE WARRANTY ON THERMAPAN SIPs?
Thermapan offers a 7-year structural warranty. We have been manufacturing SIPs since 1981 and in that time, we have never experienced a claim. Thermapan SIPs are approved by the Canadian Mortgage & Housing Corporation.