Fixing a wall plate

[Ooops]

I had to replace a section of wall plate because it was rotten. I used wood of the same width and thickness as the original 4x1. I have fixed the joists to it using a skew nail but I can now lift the joists and the wall plate comes up to, obviously. It's all very loose and springy now . I'm assuming you can't screw the wall plate to the sleeper wall as it would make a hole in the DPC. The length of section I replaced was about 1.5m and there are 4 joists resting on it. It is in the corner of the room if that makes any difference.
How I can sturdy everything up?
Cheers

 

[masona]

This does happen, re-bed the wallplate again and leave it for as least a couple of days and instead of nails use a drill for a pilot hole then use screws with a cordless drill. The reason for this you're not bashing the wallplate about with the hammer, need a lot of care when doing this.The way I do my dpc on the wallplate is to glue it with bitumen paint onto the 4"x2" wallplate then bedded onto mortar

 

[noseall]

you could always notch in some galv bent straps and drill and fix lower down, or even concrete them in.