concrete tile roof

huangyhg

concrete tile roof
i was figuring out the dead loads for a wood tower on a wood building. the wood tower has a concrete tile roof. i was planning to use 15 psf as weight of my tile. my co-worker is saying i am being too conservative. he says the weights vary from 9 to 12 psf. what is the general weight that i should assume for concrete tile?
do towers have sprinkler systems, i would like to know if i need to add the sprinkler dead loads to the tower dead loads as i did for the main roof.
how thick is it?
looking at the arch'l drawings it is about 4" thick
that seems awfully thick, unless it is the spanish tile which is curved, but only about 1/2" thick.  with the flat tile, you are looking at only 3/4" thick if my memory serves me right.
if it is a full 4" then you are looking at 40 to 50 psf, and that is ridiculous.  normally 15 to 20 psf depending on the material, the manufacturer, and the style.   
mike mccann
mmc engineering
4" thick and only 15 psf?  you sure it's made of concrete?
at another location, i have another tower with a clay tile roof. would that be also the same weight as the concrete tile or would it be lesser?
clay?  i would think lesser.
best thing to do though is to get the exact material spec from the architect, then call the manufacturer and get the actual per square weight, and divide that figure by the actual coverage area they get per square, normally 90 to 100 square feet.  
when you are dealing with tile roofs, long term deflection can be a problem, reading every major beam in the roof if it is too great.  don't be afraid to be conservative with your dead loads.  it may save you a lot of future headaches.
mike mccann
mmc engineering
for clay tile, the western woods use book, on page v-7, suggests 9 to 14 psf, and adding 10 psf if mortar is used.
for 2" book tile, they suggest 12 psf, and 3" 20 psf.
other tile types i see in the list range from 10 to 19 psf.  
bottom line is you really need to know what you are dealing with here.
mike mccann
mmc engineering
as per the arch'l drawings, there is a layer of felt underlayment. does that replace mortar for the clay tiles ?

take a look at a clay or concrete tile website, like monier (