Installation Guide

APPLICATIONS FOR AQUABAR
®
“B”
UNDERLAYMENT MEMBRANE
THE DETAILS SHOWN HERE REFER TO GENERALLY ACCEPTED
WOOD FLOOR INSTALLATION PRACTICES
Aquabar “B” is an extremely effective moisture vapor retarder for use under wood flooring. It is a cleaner and easier
handling product than roofing felt and poly film. Aquabar “B” slows moisture migration and is a superior vapor
retarder. It is not a waterproof membrane.
Under wood floors, Aquabar “B” serves as a moisture and
vapor retarder, reducing or preventing moisture migration from
below the floor system, allowing the wood flooring to acclimate
gradually. As a semi-permeable material, Aquabar “B” is also
much less likely than poly film to trap moisture condensation
between it and the sub-floor. Installed under wood floors as a
“slip sheet”, Aquabar “B” helps keep down dust and reduces
squeaks.
This application guide provides examples of typical wood
flooring installations using Aquabar “B”. The descriptions are
brief and do not cover all circumstances that the installer may
encounter during installation. It is the responsibility of the
installer to read and follow the flooring manufacturer’s complete
instructions for proper installation of their flooring. Aquabar “B”
may be used in applications over a wood or concrete sub-floor.
JOB SITE CONDITIONS
• Building must be completely enclosed
• Site drainage directs water away from foundation
• All other interior work should be completed
• Interior environmental conditions must be at occupied
levels
• Basements and crawl spaces must be dry
• Acclimate flooring per manufacturer’s recommendation
SUB-FLOOR PREPARATION
• All surface debris and protrusions must be removed
• Check sub-floor for squeaks and repair
• Sweep and vacuum prior to filling or repairing voids
• Fill voids and level high spots, sweep again
WOOD SUB-FLOORS – NAILED
Always read and follow the floor manufacturer’s installation
instructions. For installations over wood joist construction be
sure, if above a crawl space, the ground is covered by a vapor
retarder with a perm rating of ≤0.1, such as Fortifiber’s Moistop
Ultra, and crawl space is properly ventilated. Cut Aquabar “B”
to length and position over sub-floor as needed for proper
coverage. Overlap edge seams a minimum of 4 inches. Once
Aquabar “B” is installed, snap chalk lines to desired layout.
CONCRETE SUB-FLOORS – FLOATED & NAILED
For on-grade slabs, the following conditions must be met:
• An underslab vapor retarder has been properly installed,
such as Fortifiber’s Moistop Ultra family of products.
• The slab is thoroughly dry before installation of wood
flooring. Generally, slabs must be 60 days old. Test for
moisture, following flooring manufacturer’s
recommendations.
• To be certain normal slab moisture does not reach the
wood flooring, install a vapor retarder with a perm rating of
≤0.1 – such as Fortifiber’s Moistop Ultra – over the slab.
Then follow wood floor manufacturer’s recommendation for
placement of plywood. Cut and install Aquabar “B” over
plywood as above.
CONCRETE SUB-FLOORS – SCREED SYSTEM
Install flat, dry, preservative treated 2x4s, cut 18-24" long, laid
flat at right angles to finished floor, spaced 12" o.c. and embed
in adhesive. Then lay a vapor retarder with a perm rating of
≤0.1 over screeds, install plywood and cover with Aquabar “B”
as above.
HARDWOOD FLOORS
*The Moistop Ultra
®
family of underslab vapor retarders are critical for Wood and Tile floors placed on concrete slabs.