Thursday, May 28, 2015

Working With Concrete Subfloors and Luan Underlayment




Working With Concrete Subfloor and Luan Underlayment

New and existing concrete subfloors will have to reach or exceed the minimum requirements of the latest
edition of ASTM F 710

Introduction to the new requirements can be found here along with all relevant information.

“Standard Practice for Preparing Concrete Floors to
Receive Resilient Flooring” available from the American Society for Testing
and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428;
610-832-9500; http://www.astm.org.



Depending of the type of concrete used or which cement material used
as a base for resilient flooring, in the event of underlayment failure, the
responsibility for warranties and/or performance guarantees rests with
the concrete or cement-like material manufacturer and not with the
manufacturer of resilient flooring.


1. Concrete Floors and Moisture

As usual concrete subfloors can be a source of moisture-related flooring
failures, which sometimes include concrete subfloors themselves. By its very nature,
concrete starts as a water-saturated mass which must cure and then dry
sufficiently to allow the installation of flooring.

Above-grade floors normally have only the mix water to contend with although rain, spills and
water leaks can add more water. Roughly one-half of the mix water is
consumed by hydration of the cement during the curing period, with the
rest being slowly reduced by evaporation.

Once dry enough for installation, there is little chance of future moisture related problems on
above-grade concrete slabs when used with luan plywood flooring. Concrete floors-on-ground, or below ground, have not only the mix water to consume and dissipate, they also have a
potentially inexhaustible source of moisture from the ground as well as transfer to the underlayment regardless of type.

When covered with resilient flooring as well as luan underlayment, a concrete subflooring that has been constructed on top of thesubgrade soil will become approximately as moist as the soil on which
it was installed.

Uses Of Plywood (Luan Wood) 


   What are the uses of Plywood in your home? This is a casual question that most people ask. So, here are some answers for what you can do with these pre-fabricated wooden panels. Uses of Plywood are primarily found as a building and construction material, and depending on its finish it can be used as an external piece for your home and hardware projects. On this blog in which I mainly discuss Luan, as a use of plywood, the primary use for plywood is as an underlayment for vinyl, laminate and ceramic flooring. This use is basically to ensure that the top floor appears even and has a buffer between it and the subfloor.

Other Uses of Plywood include in furniture and cabinet making, for kitchens and other household items. Plywood is a very useful material and is constructed as such to be durable and resistant to damage.

How is Plywood Made? 
CDX Plywood

  Plywood is made through the use of wood panel made from thin sheets of Luan wood veneer. It is one of the most widely used wood products.

 It is very useful as well as, inexpensive, workable, and re-usable, and usually can be manufactured locally. Plywood is used instead of plain wood because of plywood's resistance to cracking, shrinkage, splitting, and twisting/warping, and because of its generally high strength.

 Layers of Wood, which are called Vaneers,are glued together, with adjacent plies having their wood grain at right angles to each other, to form a composite material. This alternation of the grain is called cross-graining and has several important benefits: Plywood Vaneers reduce the tendency of wood to split when nailed at the edges, this is a benefit for many do it yourself jobs, especially when you consider that most "do-it-yourself'ers" are novices in jobs for the first time.

Another advantage of Plywood Vaneers is that they reduce expansion and shrinkage, providing improved dimensional stability; and it makes the strength of the panel consistent across both directions. There is usually an odd number of plies, so that the sheet is balanced—this reduces warping. Because plywood is bonded with grains running against one another and with an odd number of composite parts, it is very hard to bend it perpendicular to the grain direction. Plywood is a manufactured wood panel made from thin sheets of Luan wood veneer. It is one of the most widely used wood products.





Using Marine Plywood in Kitchens and Baths
Applications for Marine Grade Plywood
What are the Differences in Marine Grade Plywood
Is Dynea Plywood Considered Marine Grade Plywood?
Do you Need to Waterproof Marine Grade Plywood?
How to Install Marine Grade Plywood
Installing Marine Grade Plywood for Boat Building
Boat Building Plans Available Online 
Luan and Marine Grade Plywood?
What is Marine Grade Plywood

Here are a few ways of attaching plywood Subfloor to Concrete 

There are three ways of attaching the plywood to the concrete floor. They are:


 • Screws – Concrete screws are very good for secure fastening. This requires the use of a hammer drill to create a pilot hole for the Tapcons to go into and an impact driver to seat the screws. When installed, the heads of the screws must be at or below-flush, as compared to the surface of the plywood. Screws should be installed every few inches.


 • Powder Actuated Fasteners – Con-crete nails, shot into the floor work well, if you can get them to install with the heads flush or slightly below flush. They cannot be re-set or driven deeper once they have been driven-in by the powder actuated tool, so run a test before they are used. Like the screws, these should be 16″ apart.

 • Adhesive Mastic – Newer adhesives are providing an excellent alternative to more traditional methods of in-stallation. When using an adhesive mastic, the vapor barrier is not used, pro-viding some savings. However, these adhesives are expensive, making for a higher overall cost. The mastic itself is troweled in place, providing somewhat of a moisture barrier.



Once the plywood sub-flooring is installed, check the edges for any ridges caused by the sheets of plywood not laying flat or being of different thickness. Any ridges found require filling with a flooring grade wood putty and then sanding to provide a smooth, continuous surface for the wood floor to be mounted to.

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