Most balustrade channels are not tested on timber, but this does not mean they can be fixed safely, it is just that tests are mainly carried out on concrete or steel. However, please consult your own engineer about the structure you are fixing to as some timber structures could be totally unsuitable for a balustrade.

Some common fixings that can be used include:

1. Coach screws: Coach screws are large, heavy-duty screws with a hexagonal head and a sharp, pointed tip that can be used to fix the balustrade channel to the wooden structure. They are typically used for heavier loads or larger components.
2. Through bolts: Through bolts are bolts that are inserted through a hole in the wooden structure and then tightened with a nut on the other side. They can be used to fix the balustrade channel to wooden structures where a very strong hold is required.
3. Wood screws: Wood screws are designed specifically for use in wood, and are available in a range of sizes and types. They can be used to fix the balustrade channel to wooden structures where a moderate load is expected.
4. Timber connectors: Timber connectors are metal brackets or plates that are designed to provide additional support and stability to wooden structures. They can be used to connect the balustrade channel to the wooden structure and are often used in conjunction with coach screws or lag screws.

It’s important to choose the right type and size of fixing for your specific application, and to ensure that they are installed correctly to provide a safe and secure fixing. It’s also important to follow the manufacturer’s instructions for the specific product you are using, and to ensure that the fixing is appropriate for the load and structure being supported. If you are unsure about the best fixings to use, it’s recommended to consult with a professional builder or engineer.