Air vent question

[Bloosman]

I am currently ripping back the internal walls of a downstairs room, getting rid of the last remnants of lath & plaster in our house.

Initially, the removal of the lath & plaster from the window wall to the front of the house left a damp smell for a few days, but this has since dissipated and I put it down to the 100 year old material build up behind the walls not allowing air to circulate (suspended timber floor).

However, I have since discovered that the air vent to the front, an old fashioned metal grate affair, was actually only half open, the bottom half being below ground level.

I have now dug out a small area to fully open the vent as per photograph.

There is a similar vent to the rear of this room, but it is entirely unblocked and above ground level.

My query is, should I now carry out renovations to the ground in front of the house, lowering the footpath level, so as to allow the vent to be open as it should...?

I don't doubt that during periods of heavy rain, water was pouring in through this vent and beneath the floor...!

 

[ree]

You are demolishing internal stud partitions ie walls dividing rooms - Or stud walls that have been built against the stone walls?

Are all your floors suspended - is the kitchen floor solid?

You mention two metal vents for the sub area - are any other vents in place around the house? Where?

Where is any DPC located on your pics - likewise the FFL?

Have you been under the floor(s) and examined the joist tails for fungal damage and the oversite for damp?

Any signs of damp inside the house?

Pics showing all the external elevations at ground level would help? The two pics above need contexts.

 

[Bloosman]

Ree,

The "walls" I am ripping out are the stud plaster walls built against the three external stone walls and the fourth internal room dividing wall.

This is the only ground floor room in the house with suspended timber floors, the rest are solid concrete.

The joists and flooring were all replaced some 20 years ago when we bought the property, because of woodworm issues, and all joist "tails" are wrapped in a membrane type material for about 1ft. A DPC was laid direct onto the earth floor prior to the joists being replaced, so is not tied into the external walls. The room extends from the front to the rear of the house, and the vent in the image is one of two which are situated at either end of the room, below the level of the suspended floor. I've checked beneath the suspended floor as best I can, and can see no signs of water/damp.

However, as mentioned above, the vent to the front of the house is partially beneath the level of the ground outside, so I assume any rain water on the ground would be able to access the sub area, more than likely running beneath the DPC and into the earth floor, hence the damp smell I initially had when opening up the stud wall.

 

[ree]

THe stud walls built against the external stone walls were built there as a means of dealing with damp/condensation/cold walls?
What is the condition of the walls behind? Pics please.

The damp proof membrane on the oversite is a DPM not a DPC.

You might have a slate DPC in your outer walls?

As above, Pics please.