Do you use joists sistered to rim boards?
"Rimboard" is a somewhat unusual term for what is usually (in the US, at least) called a "rim joist". Since there's already a joist at the outside edge, and it's usually supported directly on the foundation (or piers or whatever foundation system you're using), there's usually* no need to sister it up. 

*Note: If you have an unusually long span, are cantilevering joists of the outside of the rim, or have some other, unusual situation, there may be cause for sistering the rim joist.