Stud wall, advice needed.

[northhertsdiyer]

I'm removing a section an old airing cupboard and will be closing the opening with a stud wall. I've had an engineer give me the thumbs up on removing it. The stud wall will be plasterboarded and tiled and a radiator and cabinet will be installed on it. The existing cupboard wall is made from structural clay tiles (hollow blocks) with lime plaster and a thin skim if finishing plaster.

The floorboards run parallel with the stud wall and perpendicular to the floor and ceiling joists. There is one joist running under the floor plate position, about 4 inches off centre. There are two ceiling joists that run perpendicular to the head plate of the stud wall.

Issue 1

I'm unsure if having one joist under the floor plate and two under the head plate is enough. Can I just install the floor plate onto the floorboards and the head plate onto the two ceiling joists in this situation? My ideas are;

1. Secure floor plate to the floorboards and head plate to the ceiling joists or
2. Add noggins between joists, then reinstate floorboards and secure floor plate to floorboards and header plate to joists and noggins.

Issue 2

I will be securing my uprights to the remaining sections of wall. I won't be able to use masonry screws for this kind of wall so my ideas are either:

1. Use toggle bolts.
2. Use a chemical anchor solution such as Rawlplug R-KEM11 Injection kit

Any guidance is greatly appreciated.