Damp Hearth & Sub-floor damp

[RushupEdge]

I recently bought a Victorian end of terrace and over lockdown have gradually been making progress with restoring it.

We ripped up the carpets in the dining room and noticed the floor boards were in a bit of a state, with some breaking away. I should also add we had the house re-wired and central heating installed. The external patio has been laid too high (it meets the bottom of the airbricks) and we're in the process of taking the slabs away from the wall and digging a bit of a drainage trench until we can afford to re-pave.

With all that said, we've noticed that the hearth itself seems to have developed a few damp patches.

We pulled up the floorboards and managed to dig out lots and lots of sand and rubble that was piled up around the edges of the room and the front of the hearth. Some of the rubble in front of the hearth included lots of chunks of slate, which I'm assuming is the damp proof course...

It also looks like the front of the fender wall has collapsed or been broken:

You can still see a bit of slate to the left of the image. At first I thought the white substance on the bricks might be mould, but having looked close I actually think it might be salt?! (There are no signs of mould on the bottom of the floorboards), though there are a few damp stains in places.

We were due to have the hearth replaced and re-tiled as well as a fireplace re-instated - does this wall need to be re-built properly?

Could that be causing the damp in the hearth?

One more bonus question that could be related -

On the other side of the room we also noticed this issue -this is directly below our under stairs cupboard where our water and gas meter are. The light grey cables are the old electrics with the darker grey cables being the newer install.

As you can see, there seems to be a rather large damp area... This looks far bigger than just a condensation issue to me, but I can't hear any evidence of running water or a leak. Do you think I should get a plumber to investigate? or is this more likely caused by something else?

Any advice on either issue would be very much appreciated...!

 

[JP_]

I had rot and woodworm all around my hearth (but I removed mine). Are all air bricks clear? Hard to tell without removing them, or removing the floor and looking from the inside, as with mine, years of dirt had piled up inside them (as well as them being painted over, concreted over etc!)

The understairs damp looking patch could just be stained from a leaking radiator pipe or something during the work. Does it smell damp, or feel wet at all?

 

[JohnD]

have you got a water meter?

 

[RushupEdge]

I had rot and woodworm all around my hearth (but I removed mine). Are all air bricks clear? Hard to tell without removing them, or removing the floor and looking from the inside, as with mine, years of dirt had piled up inside them (as well as them being painted over, concreted over etc!)

The understairs damp looking patch could just be stained from a leaking radiator pipe or something during the work. Does it smell damp, or feel wet at all?

There's definitely a musty damp smell in that area when the boards are lifted.

The air bricks are clear as far as I can see, however as mentioned the bottom of them is touching the top of the patio (no idea why it was built up so high! a true facepalm moment if I've ever seen one...), so this needs to be lowered.

have you got a water meter?

Yes, it's in the under stairs cupboard located above the back of the 'damp patch' area in the bottom pic, but it's an incredibly old one.

 

[JohnD]

it's in the under stairs cupboard located above the back of the 'damp patch' area

It is quite likely you have a leak.

turn off all the taps, and look at the meter with a torch. If there is an air bubble under the glass, it will move whenever water is flowing.

However, if there is a leak between the road main and the meter, the meter will not show it.

Do you have an outside stopcock, for example in the pavement?

 

[RushupEdge]

It is quite likely you have a leak.

turn off all the taps, and look at the meter with a torch. If there is an air bubble under the glass, it will move whenever water is flowing.

However, if there is a leak between the road main and the meter, the meter will not show it.

Do you have an outside stopcock, for example in the pavement?

Doesn't look like there is an air bubble under the glass but I'll take another look.

We have an outside stopcock in the boundary box, however it's a shared supply with the neighbour so turning that off could be problematic.