Vertical Support of Stone Veneer - Defl. Limit
Vertical Support of Stone Veneer - Defl. Limit
(OP)
I have a 32 ft opening (L/600=0.64"), where i am supporting stone veneer.
Per the Indiana Limestone handbook, they reference the lesser of L/600 or 1/4" for vertical deflection limits.
The 1/4" seems very stringent. Does anyone have a way I can justify not using the 1/4" limit?
Thoughts?
Per the Indiana Limestone handbook, they reference the lesser of L/600 or 1/4" for vertical deflection limits.
The 1/4" seems very stringent. Does anyone have a way I can justify not using the 1/4" limit?
Thoughts?






RE: Vertical Support of Stone Veneer - Defl. Limit
Dik
RE: Vertical Support of Stone Veneer - Defl. Limit
We've struggled over the 0.3" limit in the past. The questions that seem to arise:
1. Does the "total load" include the self-weight of the stone/masonry? We think technically it does but realistically the upper portions of the wall don't see the same stresses as the first courses do. We've tended to use about 50% of the wall weight because of this.
2. Can you preload the beam downward and as the masonry/stone is installed reduce the load so the masonry sees no net difference in deflection under self-weight? This is true but perhaps impractical to actual do in the field.
3. Can you add expansion joints in the masonry/stone such that the accumulation of deflection across long spans is minimized - essentially avoiding tensile and compressive stresses by panelizing the masonry/stone? I think this is a valid approach.
RE: Vertical Support of Stone Veneer - Defl. Limit
The absolute statement of maximum deflection is a complementary one that of course if more stringent it is also preventing the formation of cracks (you enter a higher protection mode), but everyone can understand that the main intent is aesthetic in this case in the sense of that it is thought that above such visible deflection the bottom of the supporting element becomes unsightly. It may also mean an expected degree of maximum deflection from a tolerance viewpoint for windowmakers.
The question is if stated as enforceable, or you can subject the design to your own different criterium.
If enforceable, read with attention the code searching about:
1. Are the total loads dead and live to be considered? for example in spanish CTE typically one would only need to enter half of the live intervening loads (if you assume connection that would show even in a lintel item from cemented behaviour).
2. Typically in CTE when considering the integrity of the elements, for the more stringent serviceability check a 1/500 only DL+SDL+0.5LL hypothesis in which the loads to be entered are only those incurred AFTER the construction of the element is to be considered. Is there any clause in this intent in your code? CTE is seeking what will add to the initial status, the "live deflection", such way it is specified.
Note there are other different applicable deflection limits in CTE. I only bring these comments here to show how small caps may produce a difference.
RE: Vertical Support of Stone Veneer - Defl. Limit
RE: Vertical Support of Stone Veneer - Defl. Limit
RE: Vertical Support of Stone Veneer - Defl. Limit
RE: Vertical Support of Stone Veneer - Defl. Limit
Thanks again.
RE: Vertical Support of Stone Veneer - Defl. Limit
Im still a little skeptical of the 1/4" requirement from the ILI.