Adequate moisture/vapor protection below on-grade maple flooring
systems is essential to insuring problem-free installations. Typical
floor system constructions incorporate two moisture barriers; one
placed immediately below the concrete slab and the other placed directly
on the concrete surface, immediately below the floor system. All MFMA
(Maple Flooring Manufacturers Association) milling members recommend
a damproofing membrane (under-the-slab moisture barrier) and require
a surface vapor barrier (above-the-slab vapor barrier) to insure proper
protection from moisture infiltration.
Under-the-slab moisture barriers -- Concrete
subfloors shall have an adequate moisture barrier beneath and at the
of the slab. These barriers must be chosen on the
basis of the project site, building construction, soil type, etc.,
and shall be selected
and specified by the project architect/engineer.
Above-the-slab vapor barrier -- shall
be incorporated into maple flooring systems in addition
to any specific the specified
under-slab moisture barrier. Commonly specified surface
vapor barriers include; seam-sealed polyethylene
film and/or seam-sealed closed-cell
polyethylene foam underlayment. In parquet systems
utilizing adhesives adhered directly to the concrete,
an above-the-slab vapor barrier
is not applicable.
In practice, even after recommended
drying time, occasional residual moisture may remain.
Surface vapor barriers may assist in preventing
the ill effects of undetected moisture. The principal
purpose of above-the-slab vapor barrier is for
dew point condensation related
to slab temperature and environmental conditions.
Migration of this moisture into flooring system materials may result
related problems, e.g., cupping, compression ridging and, in more extreme situations, buckling, mold/mildew,
etc., even permanent irreparable
damage. These barriers are typically recommended
by the specified floor system manufacturer and shall be specified
the project architect.
1. Follow MFMA milling manufacturer's guidelines for proper surface
2. MFMA does not endorse "below-grade" maple systems installations
without the inclusion of adequate moisture protection.
you have additional questions, please contact MFMA's Technical
Director at 847-480-9138.
Rev. February 2005
© Copyright 2005