One of the most common questions we get regarding installation is centered on the type of mortar mixes that we recommend using with our products. Currently, we recommend using either Type N or Type S mortar. Let’s look at some basic information about mortar and the differences between these two mixes.

There are actually quite a few types of mortar mixes. The most common type that is currently used today is a Portland cement and lime based masonry mortar mix. This type of mix includes Portland cement, lime, and an aggregate or sand with water. The ratios of cement, lime and sand used in each mix will affect the characteristics for that particular mix.

Portland cement is the workhorse of a good mortar mix. Portland cement contributes to the compressive strength of the mortar mix. Lime provides “workability” and elasticity to the mortar mix, allowing the mortar to easily be applied to masonry veneer and ensure water retention of the mix. Portland cement and lime together creates the bond strength of the mix, or how well the mortar mix bonds the stone to the wall. Sand or aggregate is used as filler in the mix and allows the mortar to maintain its shape during installation.

The American Society for Testing and Materials (ASTM) recognizes 5 formulations, with each formulation designated by a specific letter: M, S, N, O, and K. Type M mortar mixes have the highest strength and Type K is the weakest.

Generally speaking, a Type S mortar mix will have a higher percentage of Portland cement than a Type N mortar mix. Type N tends to utilize a higher percentage of lime, allowing a Type N mortar mix to have better water retention properties and better workability. However, the lower amount of Portland Cement used in a Type N mix reduces the strength and freeze-thaw resistance of the Type N mortar mix in comparison to a Type S mortar mix.

Another type of mortar mix that is gaining popularity is a polymer cement mortar mix, or polymer-modified mortar mix. Polymer cement mortar mixes utilize polymeric admixtures that help to increase the compressive strength and bond strength of the mortar mix. While polymer-modified mortar mixes may be slightly more expensive than Type N or Type S mortar mixes, they provide many enhanced characteristics that may be valuable for many types of applications.

One type of installation that can benefit from the use of polymer-modified mortar mixes are installations performed in cold weather climates. The issue of freeze/thaw cycles is a common concern among masons, contractors, homeowners, and architects. Polymer-modified mortar mixes provide an added bond strength that will help to prevent detachment of the stone from the wall due to damage of the mortar setting bed from the freezing and thawing of moisture in the mortar.

Another excellent use for polymer-modified mortar is with dry stack (groutless) installations. Unlike Type N or S mortars, stones applied with polymer-modified mortars can be shifted or moved for a period of time after the application. Once a stone if seated with conventional mortar, any subsequent movement of the stone will weaken the bond. This is important when one considers the potential to bump a previously applied stone when installing dry stack in which stones are purposely in contact with each other. Type N mortars provide the least performance when installing stone in a dry stack application. Any installer should elect to avoid Type N for dry stack applications.

Mortar mixes can also include items such as various admixtures, bonding agents, and color additives. Most admixtures or bonding agents are used to increase the bond strength of the mortar mix and are typically used in Type N or Type S mixes where enhanced bond strength may be required for local building codes or for extreme climates. Color additives, such as iron oxide pigments, can be used to adjust and change the color of the mortar mix. Colored mortar mixes provide personalization of any installation and can greatly heighten the appeal of the stone installation. For Eldorado Stone, admixtures, bonding agents, or color additives are not required, but may be used in cases that require certain properties from the mortar mix in use. It is important to note that the addition of pigments has the unintended consequence of reducing the strength of the mortar. The reduction is proportional to the amount of pigment used. Therefore, it might be a wise choice to graduate from a Type N to a Type S mortar or from Type S to polymer modified in order to compensate for the lower bond strength.

When considering the addition of bonding agents, choose one that is recommended by the mortar manufacturer or the bonding agent manufacturer that is appropriate for addition to wet mixes. Many bonding agents (white liquids known as “milk” due to their resemblance to milk) are common in the industry. However, these products are designed to be applied to a cure concrete surface to enhance the bond of wet concrete to that cured concrete surface; they are not designed to be mixed into concrete or mortars.

Mortar mixes have been used for hundreds of years and have been through many formulation changes. Manufactured stone produced from lightweight concrete, such as Eldorado Stone, qualifies as an adhered veneer cladding system under building codes, which requires bond strengths of 50 PSI or greater. For most applications, Type N, Type S, or polymer-modified mortar mixes are more than adequate to get the job done. In some cases, the use of Type S or polymer-modified mortar mixes may be an industry “best practice” that should be considered.

Although mortar can be prepared from cement, lime and sand, it is wise to choose a product that is pre-packaged and has the designation “Meets or Exceeds ASTM C270” or "Meets or Exceeds ANSI A118.1A”.

Recreating old spaces into new oases is kind of our thing. One space that often gets overlooked is your own backyard. With Eldorado Outdoor, you can easily create kitchens, fireplaces, firepits, and seating areas that will transform your bland backyard into a truly inviting space!

Here is one great project that turned from "blah" into a tropical oasis, featuring Eldorado Outdoor's Gas-burning Outdoor Fireplace, Straight Cabinets, and Columns. The fireplace was finished with a natural stone veneer. The columns for the pergola were finished with a custom color Coastal Ledge.

Eldorado is proud to have a showcase presence in the 2012 Sunset Idea House, a Blu Home Breezehouse in Healdsburg, California. Set in the heart of California wine country, the Breezehouse would not be complete without a wine cellar—the perfect place to feature the clean lines and elegant design of Eldorado Stone® Oyster Cut Coarse Stone.

The Breezehouse is no ordinary home. It is an affordable yet upscale modular home that is not only beautiful, but environmentally friendly. With a variety of modules available, it is highly customizable and can be transported in a standard cargo container, dropped on site and unfolded into its chosen placement in as little as one day. Built in a state-of-the-art facility using proprietary steel framing technology, the homes require lower maintenance, and are much stronger than conventional construction. Eldorado Stone® is a wonderful complement to Blu Homes, sharing the goals of affordability, adaptability and ease of construction.

As sponsors for this wonderful home, we are also featured in an "Ask the Expert" article on Sunset's website. You can check out our answers HERE.

Considering what our company does for a living, we consider ourselves to be fairly cutting edge on all things design and color related. Every now and then, we are blown away. This website, Houzz.com, blew us away! This website caters to thousands of users who range from manufacturers to designers to end users, offering millions of photos for design inspiration.

Check out just a sampling of what we currently have posted:

Eldorado Stone Featured on Houzz

Houzz- Kitchen Remodel, Bathroom Remodel and More »

Browse Accessories And Decor on Houzz- For Example:

Books · Fireplace Accessories · Frames · Home Electronics · Indoor Fountains · Indoor Pots And Planters · Pillows · Rugs ·

Specifying the type and thickness of sheathing to be used for building construction is typically the responsibility of the building designer or architect. Sheathing’s principle purpose is to provide restraint from racking of the structure.

Sheathing that has been specified by the designer becomes of interest to the Masonry Stone Veneer installation. Indeed, masonry stone can be installed over a wood or metal stud wall even if no sheathing is required for building design purposes. However, the presence of sheathing provides significant benefit to the completed installation as well as the installation process. For example, sheathing provides a firm surface or back‐up when applying scratch‐coat or pressing stone into place. Once the stone is installed, the wall can withstand impact much better if sheathing is present.

Fortunately, buildings are infrequently designed with no sheathing requirement. The most frequent sheathings are OSB and plywood. Again, the choice and the thickness are in the hands of the designer. It is important to note that the sheets of sheathing should never be butted together when installing. Instead, a gap of 1/16” to 1/8” is preferred to accommodate the typical expansion wood products experience. Construction crews commonly use a 16‐penny nail as a gap device when installing wood sheathing.

The presence of a wood sheathing simplifies the installation of WRB since stapling to attach WRB can be performed directly into the sheathing. NOTE: It is important to note at this point that lath MUST NOT be fastened into sheathing… lath must be fastened into studs beneath the sheathing.

Other sheathings are also acceptable for use when installing Masonry Stone Veneer. Among these alternatives are cement board type of sheathings. The same installation guidelines apply… install WRB, lath and scratch coat as usual. For EXTERIOR applications, it is not acceptable in the view of MVMA to attach Masonry Stone Veneer directly to the cement board. Some cement board producers promote this direct bond approach for exterior applications, however, MVMA has not tested nor has MVMA received test results that prove such an installation is not subject to cracking at the cement board sheathing joints. There is concern that as a result of temperature fluctuations, the sheathing will shrink/expand that thereby created stress at the sheeting joints. This is not a concern when WRB, lath and scratch are employed since the stone is applied to the scratch coat which is not intimately attached to the sheathing directly.

Regarding direct attach of stone to cement board, the ONLY exception that is allotted is for INTERIOR applications. For interior installations involving cement board type sheathing, direct attachment of the stone is allowed. Since the wide temperature fluctuations will not be experienced with interior situations, direct attach to cement board is acceptable.

For those applications that include no sheathing, paper backed lath is heartily endorsed. Although installations of the stone for jobs involving sheathing can begin after 24 hours of scratch coat cure, it is advisable to allow the scratch to cure for at least 48 hours when no sheathing is present. The scratch must be stronger/stiffer to withstand the vertical forces exerted when the stones are installed. Other “sheathing” surfaces to be considered are insulation board, for example. The introduction of a foam insulation layer provides unique challenges but these are addressed depending on the thickness or foam and the type of design involved. Each of these potential scenarios can be handled, but it is best to discuss each design with your Eldorado Stone technical representative. Surely, there is no direct‐attach possible with a foam surface. In general, the type of fastener used to install that lath is affected based on the thickness of the foam insulation layer. Eldorado Stone technical support can direct you to the best information for fastener selection. When dealing with foam layers, there are opportunities for WRB changes, as well.

Eldorado Stone was recently certified by UL (Underwriters Laboratories) Air Quality Services as a Greenguard Certified product and suitable for achieving credit for LEED under Indoor Environmental Quality. Greenguard Environmental Institute is a third-party organization that assists with setting standards and certifies products and materials for low chemical emissions and is widely accepted by sustainable building programs, such as LEED. This means that using our products can help earn additional credits in several subcategories under Indoor Environmental Quality and is very important for certification of buildings under LEED for Schools and many other LEED building programs.

Eldorado Stone is a part of a handful of manufactured stone veneer companies who have this certification.

We updated our Technical Data Sheet with new test results.  Eldorado Stone is designed to meet or exceed building code requirements. Independent testing confirms compliance with ICC-ES Acceptance Criteria 51 for Precast Stone Veneer.  

See our technical data sheet for more information.

By Rick Garagliano

When installing Adhered Concrete Masonry Veneer, the issue of Expansion Joints and Control Joints must be taken into consideration.

First, we must understand the purpose of a joint and difference between an Expansion Joint and a Control Joint. In either case, the purpose of the Joint is to accommodate relative movement of the large, homogenous areas. Expansion and Control Joints provide for the unavoidable movement in a wall that will occur. These designed splits provide a location for the inevitable cracks to form such that they will be less noticeable. After all, cementitious materials are subject to dimensional change caused by thermal changes. In addition to thermal changes, shifting and settling effects can cause movement in the vertical surfaces/walls.

An Expansion Joint is a split or joint that is designed into the structure and extends through the entire width of the wall. Great examples are the joints that form when two tilt-up panels are butted together. In this case, the joint extends completely through the wall. A Control Joint is a separation that is designed into the outer layer only of the wall such as the façade layer. Control Joints are required by code for stucco coatings so that the location of the inevitable cracks is controlled, hence the name “Control Joints”. The code and the designer say “crack here and not anywhere”. Since much of the code requirements for Adhered Concrete Masonry Veneer (ACMV) were initially based on codes for stucco, the Control Joint issue would seem to apply to ACMV. However, recently, a study was commissioned that investigated the need for Control Joints when installing ACMV. The study and report (published on the MVMA website-masonryveneer.org) maintains that when it comes to thermally induced movement, stucco and ACMV do not behave alike. Stucco is a monolithic, vertical panel whereas an ACMV wall is a vertical array of individual stones. Whether grouted or not, the stone wall contains a control joint between every stone. If thermal or mechanical movement is induced, the stone won’t crack but the grout joint of dry joint would “absorb” the movement. Of course, stucco will show the crack if movement occurs. In short, Control Joints are NOT needed for ACMV.

Although Control Joints are not needed for ACMV, Expansion Joints are designed into the job by architects and are needed for the building, not the facade selection. Do not install stone across Expansion joints such that they bridge the Expansion Joint (even if the joint is filled flush to the surface). Eventually, there will be movement at this joint (as designed) and any stones which bridge the joint will crack. The best solution is to terminate stone at each site of the joint, thereby leaving the joint open and uncovered. Sometimes, the stone is installed across the joint and a saw is used to cut the stone on each side of the joint. This method provides a straight, clean cut on each side of the joint. Otherwise, the stones are cut and installed individually along each side of the joint.

Eldorado Stone is pleased to be attending the Architectural Digest Home Design Show in New York beginning March 22nd – 25th at Pier 94. With an expected attendance of over 40,000 people; ranging from designers, builders, architects and homeowners it looks to be a very promising event. Eldorado Stone will be displaying its contemporary Birch LedgeCut33 and debuting The Giada, a hand-crafted contemporary fireplace surround from Eldorado’s New Fireplace Surround Collection. If you are in New York during the show, please stop by our booth.