Product Frequently Asked Questions

Product Frequently Asked Questions

How do I install Sure Cavity™ on a masonry or concrete backup wall?

In most applications, Sure Cavity™ (SC 5016, SC 5032) and ,10mm Sure Cavity™ (SCMM 2516, SCMM 2532) are sandwiched between a moisture resistant system on a structural backup wall (in this case CMU or concrete) and expanded metal lath that the scratch coat mortar is embedded into. Sure Cavity™ can be temporarily held in place with dabs of Sikaflex® AT-Connection (seewww.sika.com/dist-news-flex-at-connect). Immediately install expanded metal lath and fasten as to lath manufacturer’s specifications to meet code requirements (see ASTM C1063–06 and the Northwest Wall and Ceiling Bureau's Field Technical Information). 

For more information, visit HyperSpecs® Wall Details
If you have additional questions, call 1-800-879-3348. 

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What types of fasteners should I use for applying Sure Cavity™ to sheathing?

In most applications, Sure Cavity™ (SC 5016, SC 5032) and 10mm Sure Cavity™ (SCMM 2516, SCMM 2532) are sandwiched between a moisture resistant system on a structural backup wall (in this case a nailable sheathing) and expanded metal lath that the scratch coat mortar is embedded into. Sure Cavity can be temporarily held in place using a common hammer stapler with staples long enough to hold into sheathing. Remember, this is a temporary fastening only. Use as few fasteners as possible. Immediately install expanded metal lath and fasten as to lath manufacturer’s specifications and to meet code requirements (see ASTM C1063–06 and the Northwest Wall and Ceiling Bureau's Field Technical Information). 

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When installing Sure Cavity do I overlap courses or line up the channels?


No. End and course edge lapping of the corrugated plastic is not required. However, do lap the four inch fabric skirt on top of the course beneath it to stop the mortar from clogging the channels.

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How is Sure Cavity installed around corners?


Corners, both inside and outside, are recognized stress points. Good construction material application practices recommend that materials wrap around corners and extend onto wall surfaces to the nearest structural member in an alternating pattern every other course. (This statement does not apply to corners that are expansion joints or control joints.)

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Why are moisture control systems from MTI preferred over other systems? (Mesh systems, dimples, furring strips, etc).


The key word here is “systems.” Details make up systems. Masonry Technology Inc. is the only manufacturer of rainscreen drainage technology that designs, manufactures, and markets complete systems. Communication is another reason MTI’s moisture management systems are superior. MTI leads the industry in communication technologies with highly detailed wall drawings, installation animations, and online webinars.

Better technology with better detailing and better communication skills result in better moisture management systems.

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I see buildings with Tyvek and other housewrap installed. How are these different from MTI’s products?


The discipline of moisture management can be separated into two major categories: moisture resistance materials and drainage. MTI is in the drainage business. House wraps like Tyvek®, and in fact all moisture resistant systems, function better when installed in conjunction with a predictable drainage system.

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I don’t see a detail drawing that fits my project. Where can I find one?


Masonry Technology Inc. works with customers to create custom details on a daily basis. MTI has a in-house Graphic Design Department. Masonry Technology Inc. is the only rainscreen drainage plane manufacturer in the world that can actually interpret your moisture management detailing needs and create graphic art pages and animations, literally within hours of you communicating your needs.

Masonry Technology Inc. has a "Detail Hosting" service for specifiers. Here is an example of how it works: A customer calls with a moisture management detail on a project that they are working on. They have concerns about a particular detail that is critical to the overall performance of a moisture management system. MTI takes the customer's information about the detail, generates accurate graphic art in the form of detail pages, generates animations from the graphic art, hosts it on MTI’s website, and gives a link to the customer. The customer can take this link and share it with the people that are required to create the detail. The “trades people” are then required, as part of a specification, to view this animation before bidding or executing this work, and they are required to sign in to view this information. The result is a better informed installer and hopefully a better detail.

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The climate isn’t very wet where I live. Is it really worth the money to install Sure Cavity?


The moisture damage risk factor does vary with the amount of moisture that may be present. That is true from geographic location to geographic location. It is also true from within the same building, from detail to detail.

Risk from moisture intrusion damage varies. What is also true is that the amount of moisture and the amount of damage varies. Sometimes, a very small amount of water does a great deal of damage.

In most cases, the cost of managing risk costs less than damage from the actualization of risk.

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Why should I use the L & R Weep Screed from MTI instead of another weep screed?


You would think the term “weep screed” meant a screed that can weep out water. Unfortunately, that is not true. Some of the major weep screed manufacturers actually say so in their literature. In literature for their weep screed, Alabama Metal Industries Corporation states “The holes in the 'V' stop act primarily as a keying mechanisms and also offer minor moisture weeping capabilities. As stucco cures it will shrink slightly away from the “V” stop allowing moisture to flow down the building paper and exit down the sloped surface.”

The draining capacity of three-coat stucco without a rainscreen drainage plane is virtually non-existent, so it really doesn’t make much difference if a weep screed works or not. But when a high quality drainage plane is installed, moisture will move from a high point in a wall, where it enters, to a low point quickly. If the weep screed provides inadequate drainage, it will be a real problem. The L & R Weep Screed really does weep. The L & R Weep Screed was designed to weep, and that is the difference.

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Why are MTI’s weep systems better than weep tubes or ropes?


There are people that believe weep tubes and sash core ropes efficiently drain or wick moisture out of cores and cavities of masonry walls. They are wrong. The only time these devices work is when you do not need them. Water does not drain out of the tubes or wick through the ropes. What actually happens when moisture does drain out of walls at these points is when the tube or rope forms the bottom side of the bed joint and voids are created at the 5:00 and 7:00 position. Why would moisture rise up to run out a tube? And as far as ropes wicking moisture out of cores or cavities or masonry walls, I have one recommendation: do not get in a wicking contest with masonry.

MTI weep systems work, because they form the bottom side of the bed joint of mortar creating 4 (¼” x ¼” holes) every 9 ½” at the lowest point of the core or cavity of the masonry wall. Weeps work when there are a lot of them and when they are all at the lowest point of the core of cavity. It’s a math thing (more works better).

Weeps do not work until the moisture gets to them, so do not forget the rainscreen drainage plane portion of your moisture management system.

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Where can I buy Sure Cavity, Cavity Weep, Wall Opening Weeps, or other MTI products?


Call MTI at 1-800-879-3348 or email us at info@mtidry.com and we will direct you to the nearest product source.

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Can I get a sample box?


Yes! Call MTI at 1-800-879-3348 or email us at info@mtidry.com and we will be happy to serve you.

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When should I use 10mm Sure Cavity™ instead of the 3/16” version?


Masonry Technology Inc. recommends 10mm Sure Cavity™ whenever existing wall details (window trim, mounting flanges, etc.) are compatible with the depth of the product. Coastal areas of Canada require 10mm by code. Most full stone and full brick veneers should use 10mm Sure Cavity™ (SCMM 2516, SCMM 2532).

Most thin veneers (stucco, thin brick, thin fully-adhered stone) and wood cladding systems will use 3/16” Sure Cavity™ (SC 5016, SC 5032).

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What is Gravity Cavity™ and why should I use it?

Gravity Cavity™ (GC 1816, GC 1832) is MTI's economy drainage plane.  It is similar to 3/16” Sure Cavity™ (SC 5016, SC 5032) but it is only 1/8" in depth.  When your project is on a tight budget or when you can get by with the minimal depth that will still provide a pressure break, MTI's Gravity Cavity drainage plane should be your choice.  Gravity Cavity™ also comes in a "no-fabric" version for use behind siding.  Gravity Cavity™ from MTI, the economy choice for drainage in the thin veneer rainscreen building envelope!

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Where can I find product installation information?

Product installation instructions can be found in our Prodiuct section of our website.  They can also be found in HyperSpecs.  Many of our HyperSpec details have an installation animation on the main detail page.  We also have installation videos for many of our most popular porducts on our youtube channel - youtube.com/mtidry.

MTi products are generally very easy to install.  In thin veneer applications our Sure Cavity and Gravity Cavity drainage planes are simply rolled out over the WRB on the backup wall an temporarily tacked in place.  Once the thin veneer (stucco, manmade brick, manmade stone, etc. is applied, the drainage plane is permanently held in place.  Most of our weeps are rolled out onto the footing and the bed joint of mortar is placed on top of them. Simple and straight forward stuff. 

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What discounts are available when ordering product?


Call MTI at 1-800-879-3348 or email us at info@mtidry.com and we will be happy to give you a quote.

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Lath Attachment Instructions


For lath attachment instructions please reference ASTM C1063–06 and the Northwest Wall and Ceiling Bureau's Field Technical Information.

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For more information, visit "HyperSpecs® Wall Details. If you have additional questions, call 1-800-879-3348.

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