HELP Securing heavy PT wood topper on 5' cinder block wall.
The purpose of my current project is to coyote-proof the yard of our pet sanctuary so I can allow the small pets access to the yard. The yard is already cat-proof and dog-proof. Our feline and canine friends have enjoyed 24 hour access to the yard for 10 years. We recently heard reports of a coyote coming around the area and I need to keep him outside of our yard. The wall at the back of the yard is the least coyote-proof at this moment because on the back side it is only 4'tall. On my side, it is 5' tall. I had a carpenter construct some 3'Hx6'W louvered fence panels which we plan to attach to the top of the wall. I had to come up with something that didn't leave a legde on top of the block wall (or anywhere else) as a step for the coyotes (or for our resident creatures). I chose vertical louvers that span the depth of the wall (or nearly so). They are 2x8 spaced about 3" apart at 45 degree angle. I asked my carpenter to copy a wall topper made with 1x boards but he insisted we use 2x. I had no idea how heavy PT 2xs would be in comparison to what I originally had thought to build. I have links to photos of the wood topper and the block wall (with current "cat-proofing" installed) here:
The fence panels are constructed of PT 2x8 and they are heavy. I am in southern california on the coast, we don't get much wind, rain, or snow (think it's happened once in 30 years). I am not really worried about weather affecting this fence but there is a concern of hardware rusting out from the ocean air. I am careful to use only screw approved for PT lumber but not sure how the heads will fair with ocean nearby. We do also get quakes so I want to be smart about how I mount these heavy toppers. I want them to stay up forever- or at least 10 years.
My thought was to use 4x4 from the foot of the wall all the way to the top of the topper every 6' (where two toppers will come together). I would screw the toppers directly into the cap of the block wall and also into the 4x4 post. However, if I can get away with it, I'd rather use 2x4s instead of 4x4 because I think it will make the job easier. I'm only 110lbs and can't easily work with a PT 4x4x8. What I would love to do is use the 3" Tapcons I already have to attach a 2x4 to the wall (at the grout lines?) and then attach another 2x4 flush to that with Deckmate screws. Would that give me the strength of a 4x4? Maybe I can add another 2x 2 2xs on the other side of the wall? Would you screw into mortar joints (I think this is the "web"?) only?
I would appreciate some sensible advice.... not too sensible, as we are on a budget.
Nikki and the menagerie