Concrete floor damp

[JR112]

Hoping for some advice as a newbie here please. I have a 1908 (originally a semi detached house, but now mid terrace due to an add on in the 70’s). I have discovered some lovely original parquet in the main ground floor rooms but what would have been the kitchen / scullery has a concrete floor. As this is a long term reno ( due to lack of time and limited budget) I laid a temporary carpet in this room.
Now I have found that anywhere where furniture has been touching it has gone mouldy underneath. I have cut away the carpet and the concrete is dry. The room is well ventilated and no steam producing activities take place in there. It is used as an occasional guest bedroom.
Obviously I need to ditch the carpet, but what cost effective and ideally DIY solution can I put down to prevent a re occurrence please?
I suspect there is no damp proof membrane and I can’t find any source of damp or leaks. I think it may be moisture coming up through the ground? In the longer term I would like some sort of hard flooring in there and not carpet, but what can I do to help the moisture before I lay a new floor please? Many thanks in advance for any advice!

 

[IHateDamp]

When figuring out damp it can be useful to invest in some temperature/humidity meters you can buy from amazon etc. to dot around in different rooms and even in different positions in the same room
Sounds like the carpet was trapping moisture below. You could use a floorcovering that is more breathable. People on this forum have recommended wool and wool felt underlay. If you got a large rug, made of something like sisal (check bottom is breathable too) you could whip it back every now and then to have a look at anything going on underneath.
Having an unbreathable concrete floor may mean that more water is being held in the walls, which creates more humidity in the rooms which may condense on the colder floor.
I'm learning about damp, so you may get a better reply from a more seasoned member.

 

[Cubist]

It can be quite amazing how much moisture is created by a human being while sleeping. in an unheated room, even at this time of year, condensation can be seen to have formed on windows and other cold surfaces. In a heated room even more moisture is produced and much of this will precipitate out of the atmosphere as it circulates around the room - carpets above solid floors will receive much of any such precipitation. Also, theres a more than reasonable chance your solid floors do not possess a Damp Proof Membrane and therefore rising damp is another possible contributor.

 

[JR112]

Thank you both for your responses. I believe there is no DPM which may be the issue. The room is not really used much (occasional guest bedroom) and I always keep the door open and open window to ventilate. Will pull up carpet fully and try and see what is going on but I’m guessing it’s mainly lack of DPM and damp rising up through the floor… thank you very much for answering me!

 

[IHateDamp]

Hope you get to the bottom of it ! Also check your ground levels outside. They should be below your internal floor level and the DPC in your walls.