View Full Version : Stucco lath vs. Diamond lath
Wusheng Hardware are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.
mctile
Just got done floating out a shower. All the tile stores were closed today and the home deep hole was out of diamond lath. Went ahead and used the stucco lath. It was about twenty times easier to install and handle and I noticed no difference in how it held my mud. My question is this-Is there anything wrong with using stucco lath for shower mud walls?
Sponsored Links
Ron
You mean 2x2 welded wire? Or self furring lath?
I like the 2x2 16 guage wire,especially the one with the bent wire that keeps it proud of the wall.I use it in mortar beds too.
mctile
Yea, the 2x2 on the roll. Inexpensive, easy to work with, and it may be the first installation I didn't add the the dried blood collection on my T-50.
Shaughnn
Matthew,
I don't think that 2-by-2 will provide adequate support for wall mortar. The reinforcement is too far apart. It's fine for shower pans and floors, where gravity is an aid in keeping in in place but for walls you need a finer mesh.
Shaughnn
bddog
I always have some Stucco Rite left in the yard and have been using it on tubs for years.It is welded and already has tar paper backing.It has another layer of brown perforated paper and the wire is bent . Believe me the mud sticks just fine.I put it right over the studs and go for it.
Cut it with Malco shears.The stuff is straight and a time saver. It makes for a real even mud job. Not for ceilings though--Steve
mctile
O.K.- I didn't notice any difference in how the mud stuck. In fact, it keyed in much easier. So Shawn, are you saying that it will not be as strong once it has cured?
Hamilton
I use the pre paperd stucco wire that looks like chicken wire sometimes.
Difference is the guage is alot heavier and the wire is wrapped closer
together then 2". I only use this when im doing a 2 step mud job.
Shaughnn
Mathew,
I've only got my opinion on this, but I think that the larger spacing will not give the mortar as much support and it may prove weaker because of it. I'm curious to know of there have been any tests of this?
Shaughnn
mctile
I would be interrested in that as well Shawn. If I could get away from the old razer wire, it would save me both time and money. Anyone out there have any knowledge of the effectiveness on this subject either way?
Ron
PCI Portland Cement Institute has a book on cement plaster.I bought it because I want to do a traditional stucco job on my house.The book says that 2x2 is good for that but that is the maximum size.
In Western Canada that's what most masons use to wrap a house with.The mortar walls become quite strong at 3/4" plus with that mesh.They use the one that has a "step" in the wire which sets it from the wall 3/16".I buy it here in Toronto and use it mostly for mortar beds but have used it for mud walls too.A few of thenm were exterior jobs.Good stuff.
Although for a shower ,over drywall, I use the lath.Easier to handle a few sheets than a big roll that's hard to unwind. :)
cx
Mark me down as one who's never seen that stuff.
We use the same type of expanded metal lath for stucco that's used for mud beds and such. Can get it in a self-furring style, just little dimples every six inches or so, and/or with black paper attached.
I still prefer to do the two layers of paper first and then add bare lath.
Most of the corners and trim we see has the heavier 3.4(?)lb lath.
I just don't see that 2" welded wire working real well on vertical surfaces, but, then, I ain't no real stucco guy, neither.
My opinion; worth price charged.
mctile
Ron, when you said that it was hard to unroll, it made me think and I went out to my shop to look a at my roll 'cause for me it was easy to unroll. This is a 1" octogon lath. It is twisted up in the long straight side of the octogon(kind of furs the stuff out and makes it easy to get tight like dimpled lath). Sorry to mislead all you guys, but I guess I'm talking about the SMALLER stucco lath roll. Anyong ever used it?
Hamilton
That would be the same stuff i use Matt. Its good stuff it is. It makes
for a super strong shower in fact. If you ever demo a shower constructed
this way (Ive demo'd alot of them) you will have 100% confidence in it.
Its alot more common than you may realize. In fact most of the so-cal
tracts i have worked on that are floated 2 step are all prepped like this.
In fact i only use 2.5# metal lath for floating 1 step showers. I have put
2.5 over studs and scratch coated but i prefer the paperd stucco wire...
its faster ;)
John K
If you want to learn more, please visit our website DIAMONE METAL LATH.
So is it chicken wire( a.k.a poultry netting)? Got a link? ;)
Hamilton
Its not chicken wire John. It looks like it but the gauge is alot heavier.
It also comes 2 ways. With felt mounted to it and without. On the kind
that has felt attached already it has 3" of paper extending past the
wire for overlapping. If you envision running the wire horizontally
there is 3" of paper below the wire. Comes in real handy for overlapping
tub flanges and even protecting a tub while you work. I always leave
the paper heavy until my mud dries and cut off the excess at the face
of the mudwork. Maybe Matt can post up a pic? Got any scraps left matt?
mctile
I do but I have never been able to post a pic. They are all to big with my digital camera.
JoeC
I can remember one of my genral contractors making a negative remark about using K-lath ( 2x2" stucco wire and paper) but that was more than 25 years ago. I use both 2.5 diamond lath and K-lath or rolled stuc co net if it's a big job. Haven't ever had a problem with any one of them. If K- Lath will hold stucco for a 2 or 3 story building, I am thinking that it will hold tile just fine! All of the tile work I did here in So. Calif withstood the Northridge earthquake, so I guess that eitehr of the laths will be just fine.
Hey one other thing.... any recommendations on a good porcelain blade? I have a Felker TM 5 or 6 on my Target right now, but it didn't last long. Thanks for any replies JoeC
cx
Type "saw blades" into the Advanced Search, Joe, and you'll find enough discussion of diamond blades to keep you off the streets for a while.
vBulletin® v3.7.4, Copyright ©-, Jelsoft Enterprises Ltd.
Laths and Stone
Lath Integrity: You (May Not) Get What you Expect
Photos courtesy of Alabama Metal Industries Corp., Birmingham, Ala.Expanded metal lath has been a staple of the plastering industry for more than 100 years. From its beginnings in the s, the basic design of diamond mesh lath hasn&#;t changed a great deal. What has changed, however, is a growing segment of lath production that does not meet the building code. The problems, damages and associated responsibility of the installation of these inferior laths are allocated to the designer and/or the installer of record. The inherent risk of purchasing, selling and installing a non-compliant lath deserves discussion to avoid performance of the stucco cladding.
Characteristics of code-compliant expanded metal laths are defined in ASTM C-847-10 Physical Properties of Expanded Metal Lath. In this ASTM standard, the lath dimensions (length, width and expanded thickness), weights (expressed in pounds per square yard) and allowable tolerances are defined for the industry. A variety of ways exist to satisfy these criteria, such as selection of base thickness of galvanized steel; the configurations of the diamond cutters; and the amount of &#;stretch&#; the machine applies to the base galvanized coil. U.S. lath producers configure manufacturing protocols differently, but share a common objective to produce lath sheets that satisfy the required weight and dimensions within the allowable tolerances.
The machinery used to produce expanded metal lath are huge mechanical machines &#; typically more than 100 feet in length. The machines can be configured to apply Grade D asphalt building paper from jumbo rolls during lath production and packaging. The automated machinery may only require one or two men to run the lath and can produce up to 1,000 sheets per shift.
The head of the machine houses the Galvanized Coil Spooler, where the seven- to eight-inch-wide, G-60 pre-galvanized coils, weighing more than 10,000 pounds, unwind. This yields up to 3,000 sheets. The process is continuous; with unwound coil is fed into the cutting rollers that apply 20,000 pounds of pressure to cut through the solid sheet. Then, stretcher-arms attach to the coil to literally stretch the compacted diamonds out about 27 inches, as the sheet continuously runs. The machine has a sheet length cut-off that is set to the required length, typically (not less than) 97 inches, as required by ASTM C-847-10. After a period, the &#;cutters&#; must be re-tooled, to make clean cuts into the solid coil. Worn cutters yield undesirable effects of unexpanded diamonds, or diamonds that are sheared or fractured in their configuration.
The process described above produces flat-expanded lath sheets. For those flat sheets to become &#;self-furred,&#; they continue through an additional process, where either one-quarter-inch dimples or v-grooves are embossed into the face of the lath sheet. These dimples or v-grooves provide one-quarter inch of furring, measured from the back of the metal dimple or v-groove, to the face of the lath strands. This furring process also is rolled in line with the equipment and wears over time, requiring the lath manufacturer to monitor the wear. Over time, this wear can result in furring falling below the one-quarter inch that is required in ASTM C-, Table 3, footnote C.
Other &#;alternative&#; laths, like pure zinc alloy (a softer metal versus galvanized steel) and non-metallic scrims, are being advertised as acceptable laths for stucco and stone as well. While alternative products may carry a third-party evaluation report, they are not necessarily recognized by the local building code. Moreover, these laths may not be recognized by the ASTM C- as acceptable materials for installation of Portland cement-based plaster systems. Without this documentation, the selection and installation of these laths present designers and installers with an assumed risk, in terms of liability for long-term performance.
Unfortunately, contractors across North America may be installing sheets that fall short of current ASTM standards in terms of weight, length, width and/or metal galvanization. This sub-standard quality is being produced and marketed as &#;utility&#; or &#;nominal&#; lath, without intention to meet current ASTM C-847-10 standard. Examples of &#;utility&#; or &#;nominal&#; lath include G-40 galvanizing, (versus required G-60), lath sheet lengths of 96 inches (versus the minimum of 97 inches) and lath sheet weights that fall below the advertised 2.5 pounds to a 2.1 pounds per square yard. The production of utility lath offers manufacturers raw material savings that, in turn, is offered as a reduced price that attracts consumers. To further complicate the lath dealer&#;s purchase process, some manufacturers offer a &#;code compliant lath,&#; but only when specifically requested and sold at a premium price.
Yet, contractors who install stucco or stone systems according to ASTM standards depend on the dealer to provide lath products meeting industry standards. This product expectation typically is not questioned, but should be. There are various ways lath manufacturers can assure the lath dealer and installer of producing and supplying quality products. One method is requiring the lath manufacturer to submit to third-party testing reports, demonstrating compliance to ASTM C-847-10, defined under ICC&#;s Acceptance Criteria 191. This third-party testing can be performed by an IES accredited laboratory, or another third-party testing laboratory. Typically, these tags are attached to the pallet during manufacturing.
One manufacturer has developed a packaging method to take the third-party identification all the way down to individual bundles that are supplied to the jobsite; each bundle has the lath weight. Whatever the method chosen, the intent is to provide full disclosure to the dealer and contractor purchasing lath sheets produced to proper dimensions and weights as defined in the ASTM C-847-10 standard.
The Expanded Metal Lath Association (EMLA) Division of NAAMM -National Association of Architectural Metal Manufacturers is a trade association formed back in the s. EMLA&#;s goal is to promote the use of expanded metal lath in building construction by providing technical data to support the architect or engineer&#;s design needs to for lath and framing design.
In , EMLA members performed an exhaustive edit to the original EML/SFA-920, first published in . This renamed document &#;EMLA-920-09,&#; sub-titled &#;Specifications for Lathing & Plastering of Steel Framing Systems,&#; was updated with new terminology, installation details, etc. That revised document is available as a free download at www.naamm.org/technical. More recently, EMLA saw the need to publish quantitative values on transverse loading, using expanded metal lath on three-coat stucco. So, EMLA developed an RFQ for running transverse load testing on six framed wall scenarios, following the criteria outlined in ICC&#;s -AC191 (Acceptance Criteria for Evaluating Expanded Metal Lath). EMLA hired an IES accredited lab in Los Angeles, and asked the Technical Services Information Bureau (TSIB, a division of the Western Wall and Ceiling Conference) to assist by having the local union build the four- X 4-foot test frames of the six separate wall systems. The AC 191 requires six tests of each wall system, requiring 36 panels to be tested.
These systems include:
Test results are being evaluated now, and will be published for the design industry to access.
In conclusion, expanded metal lath, like many other building materials, is under extreme pricing competition in the marketplace. This competition has resulted in the production, promotion and marketing of laths that do not comply with industry standards or the building code. With these laths offered at discounts to the code-compliant laths, dealers and contractors often choose these products, because they assist with offering a bid with a lower overall cost.
To be certain you are receiving a code-compliant expanded metal lath, have your dealer send a certification from the manufacturer that the metal lath being supplied to your project has been made to the ASTM C-847-10 standard. This also can be noted on markings and or tags on each bundle shipped to your project. This provides additional assurance of installing code-compliant lath.
Contact us to discuss your requirements of metal corner bead. Our experienced sales team can help you identify the options that best suit your needs.