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. Silicon has been used around windows and also around power box area. A hose was used either pressure all around windows and no water entering around window areas. Timber panel running across bottom of window has been lifted, flashing in place and dry. Part of architrave/skirts removed in area, small piece of prick bring closest skirt removed and all perfectly dry. Guttering replaced two years ago and new fascia boards with no water issues until recently with this one happening 

[JoeAzza]

Hi @con_66  are you able to access under the house yourself, if possible, get a good torch and go under the house and check the area where the dampness is on your floor, if there is some wet area, have a look to see where it's coming from, if it's not wet underneath, it could be that the timber just needs to dry out properly, hope this helps.

[con_66]

Hi Joe. Plumber and other trades have check under house. No water leaks. There is central heating vent near one area of moisture, builder removed venting and flooring is wet on one side of vent and completely dry on other side. No water leaks under house at all, 

[JacobZ]

Hi @con_66,

Condensation from the vent certainly sounds like a possible cause. The fact it is wet on one side of it and not the other could indicate an issue on a specific side or that it is tracking down that side of the vent.

Is there any venting anywhere near the other wet spot?

Jacob