How to identify source of water coming into house?

[con_66]

Recently repainted bedroom and added new built ins. When old carpet lifted to relay new carpet there were two damp patches on yellow tongue flooring. Plumber has indicted sub floor - no water leaks. Builder indicted bricks/windows/roof - no water entry points. Two different areas of room. Have used dehumidifier/drying. Surface dries then hours later wet again. Subfloor area dry. House on piers. Any suggestions of what to do? Desperate!!!! 

[con_66]

Hi Eric. Thank you for all the info. 
Flooring that is damp is yellow tongue flooring in two different areas of room. Plumber, building/pest inspector have examined boards underneath damp patch (underside of boards dry except gif a very small area). No moisture detected in any other floor areas, walls, ceiling or roof cavity. House on bearers and joists. No water damage or moisture in sub floor area. 

[JacobZ]

Hi @con_66,

As @Dave-1 has mentioned, your best option is to have a leak detection specialist attend.

They are not the same as a building and pest inspector. As this is their specialty, they will be better equipped to give you a solid answer.

Jacob

[Dave-1]

Evening @con_66 

Cruising into town today I was thinking of your problem I was trying to think outsode the circle and have a couple of ideas to throw in the ring.

You know those water absorbing beads? DampFree 300g Disposable Moisture Absorbers - 2 Pack Put them in the middle of the damp patch, turn a clear large container upside down and tape it to the floor to seal the edges. It may pull the moisture from the boards.

Second idea, Using same said bucket, place it in the center of the damp areaand see if water is dripped into it from above. That will eliminate two potential ways that damp patch may be appearing. I fully get you may have tried both but really want you to know that with all the questions in here, someone will find or point towards an answer that may work for you.

Ideas never stop!

Dave