I am designing a mat foundation and have defined DL, LL, EL etc. and a number combinations with these loads. One of the combinations is 1.4 DL + 1.6 LL. When I look at the combination it seems like the self weight of the mat is not being factored by 1.4 whereas the other dead loads applied as part of the DL are being factored correctly. Why is that ?
The self weight of the mat or the isolated and combined footing are not multiplied by the load combination factor. All other loads are factored. To factor the self weight by a factor, you need to select the Add Self Weight and Dead weight factor option and specify the Dead Weight Factor as shown next.