I am doing an inspection for clay tile roof tommorow. Anything in particular I should look for in the engineered truss components to support the 1000lb per square load? Thank you.
I can’t answer that directly, but if you can figure out manufacturer you may be able to look it up online before you write the report. Take lots of pics so you can exmaine them before report maybe.
If you can find it online it should give you some specs on capacity and span I would think. Just an idea.
Mark, the truss-roof system should of been designed for the tiles, if they were added after the house was built on a once shingled roof there should be an engineers report stating the roof system is adequate to support the load.
Dale is correct in what he stated.
Trusses that are designed for asphalt or composite type shingles can have dead loads of around 7-10 pounds per square foot (psf). Trusses that are designed for concrete tile can have top chord dead loads of 15 psf or higher.
If you have the original design information on the trusses you should be able to determine the top chord design dead load. If not, you should contact the truss manufacturer to request help on tracking down this information. Problem with that is, it might not be possible to know who the manufacture is unless you can find a stamp on the truss itself.
This link, http://www.lbrspec.com/T-1_1.pdf
will show you a typical truss design and state all the design criteria. This one in the lower right had corner, you will see where it states TC Dead load=10
This one is designed for 10 # per sq. ft. top chord.
If this truss design was for it’s original roof tile, there should be no questions.
If this was a reroof from an original roof shingle, it could possibly be an issue.
Find out if the house was originally built with clay tile or concrete tile, and note it as such and move on.
If it was not original, again I would make note of the possibility the roof trussess were not designed for this type of roofing material and again, you did your job.
Hope this helps.
What Dale and Marcel said, and look for failure… like compression cracks in drywall. Properly-designed trusses are easily capable of supporting tile, but if there’s been a change to a heavier roof covering material, additional settling in the framing is not uncommon.
If it is truly a clay tile roof (sand cast pinto tile) than do not walk on it. If it is a concrete tile roof then walking on it too look for defects can be done if you are careful.
I agree with Brian. Clay tiles will crack if you look at them too hard!!