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cracks above windows / doors 1

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geo321

Civil/Environmental
May 17, 2015
85
Hello

I was on a visit to a recently built resort. The client is complaining of many cracks above the doors and windows (attached 2 photos)of the 1st floor. Almost all the doors have the same crack type.
I am suspecting that the lintels may have some inadequate bearing or that the roof above these doors / windows is resting directly on the blocks without any separation by a compressible material.
I am writing a report and willing to recommend that the lintel should be replaced and that investigation should take place to see if there is any gap between the soffit of the slab and the blocks.

your comments are appreciated.

Thank you
 
 http://files.engineering.com/getfile.aspx?folder=0b06a496-d321-4900-8071-659a63f6fb65&file=20161105_100103.jpg
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You are assuming the presence/existence of a lintel, not in evidence.

My point is that if you go looking for actual structural elements, e.g. by removing the sheathing, or by driving nails where structure _should_ be, you may find only air back there.

Stucco in particular triggers my suspicion, base on my limited and universally bad experience with it.


Mike Halloran
Pembroke Pines, FL, USA
 
Aside from what might be there or not, they appear to be settling cracks, and that's usually due to a variety of possibilities, but the most likely is that the contractor rushed the wall finishing to meet a deadline and didn't wait for the roof tile weight to settle out. For typical two-story houses in California, roof tiles are placed in the sheathed roof for almost a month before actually layout the tiles and putting up the drywall.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529
 
These are typical shrinkage cracks from drying shrinkage in both interior and exterior plaster. They are not structural and not related to lintels or settlement.

The separation at the door trim/facing is related to shrinkage of the materials in two different directions.
 
Thank u ron for your feedback. How can u determine if these are shrinkage cracks and not related to any lintel deficiency ? do u have any guiding source u recommend ?
 
I say the trim shrinkage is wood shrinking in the direction 90 degrees from the grain. Even that horizontal crack between openings may well be a 2x? shrinking in same way. I suspect high moisture at one time, maybe when built, now showing what happened in lower humidity. These do not appear to be structural effects.
 
Ron, Oldestguy,

How can we make the difference between the cracks caused by shrinkage and structural ones ? any tips ? thank you
 
If you really want to examine in detail, you need to observe over a period of time. Wood expansion and contraction varies with its moisture content, usually. That depends on many things, but seasonal changes are common, as with wood (tongue and groove) floors. The mitered ends of trim boards show this (expansion and shrinkage) very obviously. However, to monitor movements in wall cracks, I usually draw a line across the crack and then place cross marks on the line 2 inches apart. The periodic measurements record the distance between marks and any misalignment where the line crossed the crack. Settlement cracks usually are more evident starting where there are openings and the resulting stress increase locations as at corners, but so can shrinkage cracks. For measuring the change in dimensions over long distances, such as from floor to ceiling, I have used glued on or drilled in "markers" to measure between, sometimes with a hole indent in the center. The measuring device commonly is a metal rod (arrangement of connectors) with a point in each end to fit into those markers. Included in the "arrangement" is a machinist's dial indicator reading to at least .001" units or smaller. Of course also then there are surveying methods for such things as unlevel floors, etc.
 
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