Masonry Magazine August 2016 Page. 41
DEWALT Introduces the FLEXVOLT
struction is simply a veneer material, sepa�
Battery System
rated by an airspace, sometimes insulated,
On June 21, 2016, DEWALT introduced its new
and usually with an air and/or vapor barrier.
FLEXVOLT system, featuring the world's first batteries that
Flashings usually round out the base of the
automatically change voltage when a user changes tools. walls and at the masonry opening locations, The FLEXVOLT battery system gives users ''the power of
corded, the freedom of cordless."
extending from the substrate beyond the face
The company hosted an invite-only event for the con�
of the veneer. In cavity walls, moisture that en�
struction media at the Four Seasons Hotel in Baltimore,
ters the cavity has two preferred paths to keep
Md., to unveil this innovative product. Masonry Magazine the substrate dry: either it is moved by gravity was among the guests. to the flashing level before exiting the cavity, or The 6.0Ah battery will be available in the fall of 2016,
and the 9.0Ah battery in early 2017. The batteries power
it can become a vapor and evaporate through
DEWALT's brushless 60V MAX* and 120V MAX* FLEXVOLT tools. Batteries and tools are al�
the face ofthe veneer by means of weeps, soffit
ready being pre-sold through various outlets. vents or (in the case ofterra cotta veneers) the The key to the new batteries is their ability to switch between DEWALT tools. With pat�
ent-pending technology, FLEXVOLT batteries automatically change voltage depending on
mortar joints.
whether they're being used in a 20V MAX* or 60V MAX* tool. Two FLEXVOLT batteries (of
Cavity walls connect the exterior veneer
the same amp hour) together power the new DEWALT 120V MAX* tools. In other words,
to the substrate with wall ties that span
high-power applications that previously required corded tools can now be tackled using across the cavity. The individual ties have FLEXVOLT cordless tools. Both the 6.0Ah and 9.0Ah FLEXVOLT batteries extend the runtime of existing DEWALT 20V
many shapes and can be installed between
MAX* tools. They also power five new 60V MAX* tools and two new 120V MAX* tools (with two
courses of concrete masonry units ( CMU)
batteries). Among the new 60V MAX* FLEXVOLT brushless tools is a 7 1/4-inch circular saw.
or attached directly to the substrate, which
FLEXVOLT batteries are backward-compatible with most existing DEWALT 20V MAX* could create moisture contact directly with tools and chargers. The FLEXVOLT battery has more than3X the power than the DEWALT 18V NiCad.
the substrate wall. Using hot-dipped galva�
Several new 20V MAX* tools also operate off the FLEXVOLT system. These include a
nized or stainless steel connectors will help
portable power station and a Bluetooth LED area light. In addition to the tools, FLEXVOLT
prevent corrosion because they will be a
High-Efficiency Accessories are engineered to maximize runtime.
likely path for water to follow; however, the
For complete details, visit www.dewalt.com.
principles of a well-functioning cavity air�space will control a majority of the surplus moisture. In the past, rainscreen was a general term, usually used to
In comparison, the same basic principles exist for cav�refer to a fa~de material However, the term now typically de�ity walls and pressure-equalized walls: we attempt to man�fines the entire system of either hat channel, girt or rails, air age the water that enters the air gap between the substrate's barrier or structurally fastened insulation systems where the protective weather barrier and the veneer or fastened veneer fa~ade material is secured to a framework independently from material, and keep the inner and outer wythe drier, thereby the attachment to the substrate wall. The joints between the preventing such problems. individual units that comprise the fa~de are either sealed using
So, what is the difference between most cavity walls and gaskets or left open. Open joints can often have a semi-sealed, a rainscreen wall? In many cases, the cavity of a cavity wall, three-dimensional mesh with a backer material placed against which is typically much larger than a rainscreen air gap, will the back of the fa~de ifinsulation is not present; this allows air deflect due to external atmospheric forces and material di�and vapor to access the air gap. mensional changes. Thermal exposure will form negative When discussing open joints, we are not talking about a pressures within the cavity, possibly leading to vapor and head or bed joint that is 3/8 inch wide, left completely open. moisture penetration beyond the air barrier into the wall in�We are talking about a joint that can be configured several terior. In short, a cavity wall is not usually a rainscreen wall, ways. One of the most common is to use a slightly open ship and a rainscreen wall that has a small cavity (a.k.a. an air lap joint. The open joint is designed to allow only air into gap) is not typically referred to as a cavity wall. the air gap, and this happens when the material-to-material
Pressure-equalized walls are the basis for one type of joint, whether horizontal or vertical, fits over the lower unit rainscreen wall. The open material-to-material joints found or adjacent unit, thus preventing the passage of wind-driven in many rainscreen systems will experience pressure equal�rain. This will also work with the rainwater that runs down ization when the external wall pressures are applied to the the building because ofgravitational forces. Due to the joint face of the wall and the open joints allow the air gap pres�in the fa~ade material, water typically does not find its way sure to nearly equalize with the external pressure. It is not back up and into the wall through the ship lap joint. logical to believe that the pressures will ever be exactly the Another feature of rainscreens in pressure-equalized same. Equalization principles, or normal air movement, walls is the placement of limiters or dividers to create chan�prevent pressures found in the cavity from becoming nega�nels within the air gap to compartmentalize air movement. tive. These negative pressures, ifpresent, would force mois�This involves simply installing stainless steel, composite, ture into the substrate walls, gaps in electrical and plumbing rubber or foam strips that fit snugly in the air gap and are intersections, and areas that have exhibited displacement taller than they are wide to limit air movement to a localized (either large or very small) during or after construction. area within the wall. Pressures in the air gap (wall cavity)
www.masonrymagazine.com August 2016 � MASONRY I 39