Any body have any good articles on expansion and contraction joints? Especially on this type of rock. From what I understand it should have been designed by the designer, architect or engineer. But what are the guidelines?
since each design is unique, the a/e really needs to design the joints. more and more they just write in “where required” and shift responsibility to the contractor who may or may not be equipped to design the proper joint.
typically they are located at the steel column lines.
if your situation is “cultured” stone, try looking at owen cornings site. i think they are the largest mnfctr of cultured stone & may have some guidelines.
Is that a stone veneer over a wood-framed wall? Or a solid stone wall?
Rules of thumb for control joints in masonry are that they should be located at no more than approximately 30 foot centers, but also that they should divide the sections into rectangles which have a 2:1 ratio of width to height. Thus, for example, a nine-foot high wall should have control joints located every 18 feet, more or less. I don’t know of any articles about the subject. What I’ve written is what I was taught by an architect who knew about such things.
I have found an article which discusses spacing of control joints in concrete masonry, and which differs slightly from the rules of thumb I’ve quoted:
It is important to understand the difference between a control joint and an expansion joint. Control joints function mainly to control cracking, and may be completely independent of the building structure. Expansion joints in a masonry finish generally coincide with expansion joints in an entire building.
James, the picture you supplied seems to indicate more of a faux stone veneer than what one would expect it to be of a rumble stone pattern of field stone.
The crack would be indicative of both field rumble stone and/or faux stone on wire lath. Both would crack in the joint from expansion/contraction and/or movement of unknown possibilities.
We need to start and understand the definitions of the trade;
Provision for the dimensional change of different parts of a structure due to shrinkage, expansion, temperature variation, or other causes so as to avoid the development of high stresses. (Expansion/Contraction Joint)
**This includes all stone cut or machined to given sizes, dimensions or shapes, and produced in accordance with working or shop drawings which have been developed from structural drawings. (Dimensional Stone, Dimensioned Stone, Sized Slab, Sized Stone, Trim Stone).
**Stone that is selected, trimmed, or cut to specified shapes and sizes. Face and edge finish is as specified.
**A product term applied to dimensional stone used for building purposes, mainly walls and foundations, and consisting of irregularly shaped pieces, partly trimmed or squared, generally with one split or finished face, and selected and specified within a size range.
Is an assembly designed to safely absorb the heat-induced expansion and contraction of various construction materials.
Natural Thin Veneer (NTV) - superior to man-made stone, and lighter and easier for masons to install than full veneer - has been produced by Buechel Stone’s master stonecutters for over 25 years. Cut at thicknesses ranging from three quarters of one inch to one and one quarter inches, NTV is a lightweight alternative to full veneer and is more beautiful and durable than man-made stone, yet still remains cost competitive.
There are different qualities of “fake” stone (I call them “rocks in a box”). You want a high enough tensile strength so that the stone will not crack when the mortar bed shrinks and a strong enough flexural strength so that it can take some wall movement.
I agree with you Larry, and all I was trying to point out are all the variables to the original question James brought about that the possibilities could be endless unless the product can be clearly identified.
Whether thin natural stones, Faux Stones, real size rumble stone, brick, and whatever, the installations are all different and the reactions on most are the same, if you know what I mean. These products all use something in commen. = cementous base product for the installations.
Following the Manufacturers installation guide on faux stone would be the best insurance, but if a real natural stone masonry, their are variables that no one can control other than the Mechanic himself.
Very intricate and hard to control trade.
Good link by the way.
At 30 cents a pound for real stuff, I would go with the Faux stuff too. ha. ha.
…or been reinforced at openings with steel in the mortar joints, especially at the corners, but probably should have had control joints at the building corners, at least, and if a very long wall, control joints dividing the wall into approximately 2:1 panels. The method of anchorage to the wood framing also affects the ability of the stone to withstand differential movement. Control joint placement is more an art than a science, because the technical requirements should be balanced with the visual requirements.
James, I have read and been told about expansive soils and slabs on grade in your area and not familiar with it, so it might be even more reason to have had some control/expansion joints in the facade of the building for that purpose.
Up here, we have 8’ foundation walls that would support the weight of a stone veneer and would not have to provide to many control joints, because movements are minimal.
My only thought would be a comparison with Norther Maine where one would build a structural slab due to ledge encounters or what not, and design it to float with the frost actions of this area. Similar stresses would occurs as with expansive soils, but would have to be structurally design to obsorb such movement.
I that case, as above, control joints would have to be strategically located to serve that purpose and also be somewhat aesthetically pleasing. If you know what I mean.