Decking steps

[Keitai]

I ripped out an old decking step and replaced it with a composite one. My concern is the wood which supports it doesn't have bricks or Anything underneath. I fixed them to concrete around sides and front bit is screwed into side bits but there's nothing solid underneath. Saying that the previous guy didn't put much under either on soil

Will it be strong enough? I was thinking bricks along with fixings into sides

 

[foxhole]

Should last fairly well though with composite on small area I use composite for frame as nothing can rot .

 

[Keitai]

Should last fairly well though with composite on small area I use composite for frame as nothing can rot .

The back a d side bits are bolted to the concrete which is good but I worry about the front bit which runs along the front near main decking. It's just screwed to the side bits of wood . People will be stepping on it first all the time