Adding a Second Subnet for Virtual Server IP's

Our LTM configuration in our network is as follows. We have an External VLAN and several Internal VLAN's. The External VLAN contains the subnet 1.1.1.0/24. So, the IP's of the virtual servers are in the 1.1.1.0 subnet. We have several Internal VLAN's, for example, one contains the subnet 1.1.4.0/24. So, any nodes behind the LTM will use an IP from 1.1.4.0. So, the flow would be as follows.

VS1 (1.1.1.4) -> Pool (member nodes are 1.1.4.1 and 1.1.4.2) -> Node (1.1.4.1 or 1.1.4.2)

We are running out of virtual server IP's in the 1.1.1.0 subnet. I want to add another subnet for virtual servers, for example 1.1.2.0. What is the best way to configure this on the LTM? Can I add the 1.1.2.0 subnet to the existing External VLAN and create the self IP's (the LTM ports are trunked to our switch so multple VLAN's are allowed)? Do I need to create a separate VLAN for the new subnet? Any other configurations needed?