Drying Conditions
Before, during and after installation of a Maxxon® underlayment, building interior shall be enclosed and maintained at a temperature above 50 ºF (10 ºC) until structure and subfloor temperatures are stabilized.
Maxxon gypsum underlayments are inorganic and provide no source of nutrients to sustain mold growth. Prolonged contact of moisture with other construction materials, however, can result in mold growth. To avoid growth of mold on construction materials such as wallboard, drywall compound and even dust, it is vital to maintain a low relative humidity both before and after placement of Maxxon gypsum underlayments.
The general contractor must provide and maintain correct environmental conditions to keep the building clean and dry, and protect against infestation of moisture from a variety of potential sources. Moisture can be introduced by other trades through spillage, tracked in mud and rain, plumbing leaks, etc. Often stored in damp conditions, building products may arrive on site laden with moisture that releases after installation. Outside sources such as rain, snow, wind, etc. can also increase moisture levels.
Controlling moisture levels in the building, through appropriate trade sequencing and prevention of potential damage by other trades, is the responsibility of the general contractor. The general contractor must supply mechanical ventilation and heat if necessary. These controls fall under the scope of work of the general contractor — not Maxxon Corporation or the Maxxon underlayment installer.
Limitations
During construction, general contractor must place temporary wood planking over underlayment wherever it will be subjected to heavy wheeled or concentrated loadings. Maxxon underlayments are not to be used on or below grade, except over well-drained structural substrates as determined by the general contractor. They should also not be used in areas that have prolonged contact with water. The typical maximum depth for gypsum underlayments is 3" (76 mm). For depths greater than 3" (76 mm), contact your Maxxon dealer.
Notes
- Maxxon underlayments cannot resist stresses caused by sudden structural movement.
- The structural subfloor must comply with APA maximum span/joist criteria and be adequate to withstand design loads with a deflection limitation of L/360.
- Expansion joints in all types of work shall be brought through the underlayment.
- Maxxon underlayments require a floor covering. Contact your Maxxon dealer for recommendations for adhering floor goods. Call or write for a copy of the brochure Procedures for Attaching Finished Floor Goods to Maxxon Underlayments. It is the responsibility of the floor goods installer to determine the compatibility of their product with a particular floor underlayment.
- Concrete moisture or vapor emission must be eliminated by others prior to a Maxxon underlayment application for below grade, on grade or suspended slabs.