I am installing a privacy fence using 29 gauge PBR panels and mechanical fence post adapters similar to the Simpson Strong-Tie pictured below. Each panel will overlap one another and each post by at least 1ft.
The adapters are for tubular fence post to wood backer rails/stringers. I want to install the backer rails/stringers as shown in the picture here, in between the posts but without the vertical wood. I spoke with a Simpson strong tie design engineer who said he didn’t see any reason why I could not install the rails in this fashion. For what it is worth flush mounting rails between posts will result in a 3” wide fence vs a 5”+ thick fence. Installation is near an existing fence line and shrubs.
ozco is-fbl now discontinued
Below is a picture of (ozco is-fbs discontinued) the typical face mounted or overlap rail joint installation commonly used with these fence bracket adapters.
my questions and dilemma is that i wonder if the face mounting would offer greater framing strength some how? will mounting the rails in between the posts create a weaker spot vs face mounting? I am installing this fence in a region that has the potential for high winds60-70mph but our existing fence same materials using the face mounting installation has stood through multiple storms to date. I am installing the finished face side of this fence to stand head on in the direction of the prevailing winds. I worry that mounting the fence rails between posts will create a weakening in the framing due to a) having to install the screws closer to the edge of the wood that can lead to early degradation of the cedar (yes i planned to do pilot holes). b) i also worry that mounting the cedar rails behind the flange (between posts) with the screws could some how lead to the rails being pulled/pushed out vs face mounting the rails with the screws secured from behind the fence rail in opposition of the wind.
its also important to understand #1. Mounting the rails between the posts aka on the back of the bracket arm has the potential to create a miniscule gap between the wood stringer and the bracket/post. #2. Any use of mechanical fence brackets = fence sheer is now dependent upon the fastening screws and not the posts. #3. I will not change the design as I already have all materials and i am simply stuck on how to install the rails for this 105ft section in our back yard. #4. i will be installing PBR 29 gauge 36” wide fencing panels to the rails which i am hoping will create a stronger framing integration. the panels are rated to 60,000psi, using 20wt 50,000psi rating tubular posts.. appropriate post hole spacing and depth for my regions wind and frost.
Next I understand that the minuscule gap without being properly butted up against the next rail or post could lead to excess movement and breaking or stripping of the screws. I was wondering if the the solid PBR panels would create enough rigidity and strength to reduce lateral sheer and stress on the bracket screws to compensate for the gap between the bracket/post and cedar stringer/backer rail?