Rothoblaas X10 Moment Post Base Simplifies Post and Beam

The Rothoblaas X10 is a moment post base, which means  structurally the post is a fixed end and supports the moment forces in the structure. This allows you to simplify your design and do away with some supporting beams and all the bracing. That results in less work, less cost for timber and more space below the pergola. Every red brush stroke in the photograph below is a removed beam. This particular structure is constructed with a CLT (cross laminated timber) roof, resulting in 8 less wood members. In some structures you might even be able to remove 10 or 12 members.

Rothoblaas X10 Post

Rothoblaas X10 Post - Red shows where bracing can be eliminated

It is recommended to use the Rothoblaas X10 either with self-drilling dowels or with standard dowels / pins.

SBD Screw – Self Drilling Dowel for Aluminium Hangers https://timberframehq.com/shop/sbd-screw-self-drilling-dowel-for-aluminium-hangers/

The self-drilling dowel can perforate the timber and the post base. The video  below shows how this works .However, it is best to predrill the wood before inserting the self-drilling dowel through the steel. In this case, no realignment is needed. The WS self-drilling option is convenient because you can preinstall the post base offsite (i.e., with the post in horizontal position), as the penetration of the steel of the post base takes some time and force (the steel is 5/16 inch thick)

Dowel STA https://timberframehq.com/shop/sta-smooth-dowel/

If you go for the option with standard smooth dowels (STA12150B, highlighted in the table below), you could use Rothoblaas’ special wood & metal drill bit to make the holes (AT4010). With this, you make sure that your holes are perfectly aligned. In situations with installation on site (i.e., with the post in vertical position), the smooth dowel option might be easier and quicker for installation.

If we look up the structural performance of the different configurations, we see that S4 is the configuration with the highest performance if used as a moment connection. If not, the vertical and the lateral load performance is unchanged, regardless if you use smooth dowels or self-drilling dowels.

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