Damp underlay and crumbling floor at front door

[Dadshopbread69]

Hello all,

Wondering if this is something I can attempt to sort myself or whether I might need to get the pros in.

We are in a new build and it's around 3 years old. Developers have scarpered and are non responsive on a number of issues but I don't have the time/energy to chase and would rather just sort this.

Today I noticed the underlay under front door mat was damp and on further inspection found the following. I don't really have a frame of reference (pun intended) but it doesn't exactly look like neat work to me. The concrete seems damp and I can see atleast one gap in the door which goes straight outside.

Is this a 'call the pros' jobby, or could a guy keen to learn more DIY skills and good at following instructions and troubleshooting sort this myself?

 

[Wayners]

Dig out.See what's going on.
Drop a frame in to take a coconut mat.

 

[crank39]

Frame and coconut mat already there

 

[Wayners]

On a closer look oh yeah. Sorry.

Do you think the low threshold door is the problem with water getting under?.

 

[HERTS P&D]

Is the cill tilting backwards?

Close the door and get some one to spray the cill with a hose then move up the door to see where the leak is coming from.

Andy