21 May Spider Tie spacing and assembly
The spacing of the Spider Tie stacks is determined by a couple of factors. The first is the height of the wall and second is the thickness and type of plywood you will be using.
The taller the wall the more hydraulic pressure you will have to deal with at the lower sections of the forms. To provide enough support for your plywood you will need space the Spider Tie stacks closer together. The thicker the plywood the less support it will need. Here are some general suggestions* to follow.
- Walls up to 3′ tall- new and dry 1/2″ plywood
- Walls up to 5′ tall- new and dry 5/8″ plywood
- Walls up to 8′ tall- new and dry 3/4″ plywood, only fill forms half way and wait until concrete has begun to set up before filling the second half.
- Walls over 8′ tall- new and dry 3/4″ plywood, only fill forms 4′ at a time. Wait until concrete has begun to set up before proceeding with the next 4′ lift. Continue this process until you have filled the forms all the way to the top.
We recommend spacing the Spider Tie stacks at 16″ on center based on the plywood recommendations above. For the walls 5′ and shorter if you increase plywood thickness to the next size up you may space the spider Tie stacks at 2′ on center.
*The condition of your form plywood plays a big part in the success of your project. Always thoroughly inspect the condition of your plywood before starting any project. It’s always recommended to use clean, new, dry plywood. Rated concrete form ply, if properly oiled and care for can be used several times without problems.