About Mold

Why SIPs are the best building system to reduce mold in your structure

Mold in residences and offices is a BIG deal right now.  Over 20,000 litigation cases are currently open in the United States claiming health damage from various forms of mold.  Although there is no medical backing for health claims other than allergic reaction (8-10% of people have a reaction in a skin test for mold allergies) and certain immune deficiency conditions, there is as much hysteria over health concerns regarding mold as there was regarding asbestos a few years back.

Although residential mold has probably been around forever (it's referred to in Leviticus 13-14), recent changes in building materials, methods, and goals have increased the likelihood of mold issues.  Four things are required for mold to grow and propigate:


Mold Spores

Temperate air


Since mold spores are ubiquitous (ever present), temperate conditions are a primary building goal, and nutrients are nearly impossible to eliminate, the only thing we can really deal with is moisture.  According to Joseph Lstiburek at Building Science Corporation www.buildingscience.com , a forensic engineer that specializes in mold and moisture problems in structures, the issue is control of the wet rate of the environment or the dry rate of the materials.

This brings us to why there are more problems in new structures being built than in the past.  The premium placed on tight, well insulated homes has required materials that are less responsive to moisture- they have a low dry rate.   In addition, we build tighter and use moisture barriers, which means that any moisture that breaches the moisture barrier is trapped - the building also has a low dry rate.  Porous insulation- fiberglass and cellulose, will hold new moisture like a spnge, assuring a long term supply of moisture for mold growth. 

Since any breach will cause the problem (window or dood drain pan failure, window leaks, weatherstripping failure, penetration for telephone or cable installation, poor construction practices), stick frame construction, as it gets tighter, experiences more moisture and mold related problems.

Structural Insulated Panels (SIPs) avoid these problems a number of ways:

Since the prodect has no cavities, there is nowhere for moisture or mold to form, even if breaches are created.

Since the foam is not porous, water runs off to the low point, where it can be channeled away ("drain the rain from the plane"), even if there is a failure in the window or door drainage systems.

Since panels cover such large dimensions in uninterrupted sheets (as large as 8' x 24'), there are few joints to seal.

The splining systems are designed with sealants in mind.

The preplanning required to pre-cut SIPs gives a VERY tight, exact fit for windows and doors and no where for the drain pans to drain but out.

The tolerances for fit greatly exceed most construction standards and are generated in a factory setting, where conditions are favorable for strict quality control.

Although other building systems have similar advantages over stick frame for walls, SIPs can also be used for the rest of the building envelope, making them the most-recommended system by forensic engineers.

Just one more reason that stick framing becomes a smaller piece of the construction pie each year.


This article was written by Butch Johnson, Panel Marketing Director for General Panel Corporation.  General Panel's main page is at www.generalpanel.com .  If you have comments, please send them to bjohnson@generalpanel.com .