Cement Board Soffit Covering Without Edge Nailer
I finished all my rough framing and am putting together my materials list for siding and soffits. I have a TJI roof system with 2′ overhangs built with a 2×4 blocks for soffit support as shown in the attached picture (source https://www.weyerhaeuser.com/application/files/7915/8206/3794/TJ-4000.pdf page 29). I have a 2×8 pine fascia.
I am wanting to use purpose sold cement board soffit material (1/4″) but all the manufacturers I’m seeing are saying its needs continuous edge support. Their drawings show a 2×4 nailed to the wall and a sub facia for edge support (https://www.jameshardiepros.com/getattachment/f40a6b67-a0fc-4d0b-9559-5538dab229fe/hardiesoffit-hz5-us-en.pdf see top of page 2). Does anyone know of a better option than nailing blocks between my joist tails to the inside of my fascia and to my blocking above the top plate? Is 5/16″ vertical siding cement board going to work without edge support?