Troubleshooting Guide

5
C oncrete Subfloors Continued
Remember:
A "DRY" SLAB, AS DEFINED BY THESE TESTS CAN BE WET AT OTHER TIMES OF THE YEAR. THESE TESTS
D O NOT GUARANTEE A “CONTINOUS” DRY SLAB. ALL CONCRETE SLABS SHOULD HAVE A MINIMUM OF
6-MIL POLY FILM MOISTURE BARRIERS BETWEEN THE GROUND AND THE CONCRETE.
Grind high spots or use a Portland-cement based leveling material (minimum compressive strength 3000
psi) to fill all low spots to a maximum height variation of 1/8” in a 6’ radius or a 3/16” in a 10’ radius.
Follow the leveling compound manufacturer’s instructions. Leveling compounds must be allowed to
thoroughly cure and dry prior to installation of wood flooring.
Aspen Flooring engineered hardwood flooring can be installed on, above, or below grade. In addition, it
can be installed over above-ground, suspended concrete floors. The suspended concrete must be a
minimum of 1-1/2” thick and must be structurally sound. The exception to this is lightweight concrete
(which usually contains high amounts of gypsum) having a density of 100 pounds or less per cubic foot.
Test for lightweight concrete by using a nail to scratch the surface of the concrete. If the concrete
crumbles or turns to powder, it is not sound and you should NOT glue down the hardwood flooring.
This subfloor needs to be corrected/replaced prior to installation.
Wood Subfloors
Wood flooring, by design, is not to be used to strengthen/stiffen a subfloor and will not do so. If
movement and/or squeaking of the subfloor occurs prior to installation and is not corrected, such
movement and/or squeaking is likely to remain after the installation. ASPEN FLOORING WILL
NOT BE RESPONSIBLE FOR SUCH MOVEMENT AND/OR SQUEAKING.
Test wood sub floors and wood flooring for moisture content using a pin-type moisture meter. Take
readings of the subfloor – minimum of 20 readings per 1000 sq. ft. and average the results.
In most regions, a “dry” subfloor that is ready to work on has a moisture content of 12% or less and the
wood should be within 4% of the subfloor moisture content for engineered floors, 2% for solid hardwood
floors.
Basements and crawl spaces must be dry. Use of a 6 mil black
polyethylene is required to cover 100% of the crawl space earth.
Crawl space clearance from ground to underside of joist to be no
less than 18” and perimeter vent spacing should be equal to 1.5%
of the total square footage of the crawl space area to provide cross
ventilation.
The subfloor must be flat, meeting a maximum height variation of 1/8” in a 6’ radius or 3/16” in a 10’
radius. All subfloors and subfloor systems must be structurally sound and must be installed following
local building codes. Keep in mind that local building codes may only establish minimum structural
requirements of the subflooring system and may not provide adequate rigidity and support for proper
installation and performance of a hardwood floor. Check the subfloor for any loose areas and secure
them down to minimize the chance for squeaking. Whenever possible install the planks perpendicular to
the floor joists for maximum stability. The Aspen Flooring warranties DO NOT cover any problems
caused by inadequate substructures or improper installation over said substructures.