Bisbee_Structural
Structural
What do you typically do about frost protection for architectural landscape elements that are non-structural in the sense that they aren't supporting walls, columns, roofs, etc.?
These could include low concrete walls for sitting or separating areas of a garden, short retaining walls, etc.
The US codes don't seem to make an explicit distinction between structural and architectural elements, but I can't imagine those of you practicing in locations with deep frost lines are making the contractor dig 10 ft. to place the footing for a 2 ft. tall garden wall.
I typically take the following approach:
1) If the elements are low, typical landscape elements (and don't pose a safety hazard if they fail, according to my engineering judgement) I leave them off of the structural drawings for the landscape contractor to construct based on the architectural drawings and standard practice.
2) If the architect or client are particularly concerned about the performance of the landscape elements (limit concrete cracking, avoid tilting/sloping, etc.) I would develop a strategy to protect the foundations, like setting on a bed of gravel, in consultation with the geotech and would show the details on the structural drawings, BUT I wouldn't frost protect these foundation unless this is the only way to ensure OK performance.
3) For elements that are tall enough to catch the wind (>5 ft. wall), support structural elements, support important features (like a fountain) or could be dangerous if they fail during or after construction (>5 ft. retaining wall), I would put the footings below the frost line or maybe consider something like helical piles. I might consider doing a frost protected shallow foundation with rigid insulation on some elements, but I think this would be tricky to do in a garden with trees and roots, or where garden work might damage the insulation.
The frost line where I live is only 4 ft. though, so option 3 isn't as costly as it can be in other locations.
Would appreciate your comments/feedback.
Thanks in advance!
These could include low concrete walls for sitting or separating areas of a garden, short retaining walls, etc.
The US codes don't seem to make an explicit distinction between structural and architectural elements, but I can't imagine those of you practicing in locations with deep frost lines are making the contractor dig 10 ft. to place the footing for a 2 ft. tall garden wall.
I typically take the following approach:
1) If the elements are low, typical landscape elements (and don't pose a safety hazard if they fail, according to my engineering judgement) I leave them off of the structural drawings for the landscape contractor to construct based on the architectural drawings and standard practice.
2) If the architect or client are particularly concerned about the performance of the landscape elements (limit concrete cracking, avoid tilting/sloping, etc.) I would develop a strategy to protect the foundations, like setting on a bed of gravel, in consultation with the geotech and would show the details on the structural drawings, BUT I wouldn't frost protect these foundation unless this is the only way to ensure OK performance.
3) For elements that are tall enough to catch the wind (>5 ft. wall), support structural elements, support important features (like a fountain) or could be dangerous if they fail during or after construction (>5 ft. retaining wall), I would put the footings below the frost line or maybe consider something like helical piles. I might consider doing a frost protected shallow foundation with rigid insulation on some elements, but I think this would be tricky to do in a garden with trees and roots, or where garden work might damage the insulation.
The frost line where I live is only 4 ft. though, so option 3 isn't as costly as it can be in other locations.
Would appreciate your comments/feedback.
Thanks in advance!
