Hi guys, first question

[FBIBURTON]

Hi, Andy here from Wolverhampton.

I have a question I have lived in my 30s house a few years now. I noticed under the stairs (pantry) the floor seemed a little damp when I emptied it. There were a few old boards that had been lifted at some point, so I lifted to have a look. It seems very damp under there pictures to follow. I've noticed the previous owners slabbed outside upto the wall only leaving 70-80mm below the doc. Could this be the issue? Stressed tbh

 

[FBIBURTON]

 

[FBIBURTON]

 

[parkview094]

Picture 2 - what's on the other side of the air brick? Is it still open and unobstructed to the outside? What about the others?
Is it just earth on the ground beneath the floor?
What looks like droplets of water in your photos - are they droplets of water?
The very wet floor joist - is that on an outside wall? (The wall with the patio on the other side?)

 

[Cubist]

Hi Andy,
Sorry to say it but that's not damp, its positively and absolutely wet and what you would see as a result of a leak from a water pipe or a collection of water - above or below ground -lying against an external wall and fining a way through it to the interior. Best guess at present is that the recent heavy rains are part of the problem and that poor drainage from the slabbed path and beneath it are the root cause. As joists are getting extremely wet this can lead to rot and wood-boring beetle infection that will ultimately cause the floor above to fail. If you can, try to localise the probable the site(s) external sources of the water and investigate under the particular slabs. Look specifically for places where the DPC below the apparent level of the base of the joists has been breached.

 

[stuart45]

It looks to me like the DPC is only half a course above slab level, when it should be at least 2.
It also looks like a solid 9 inch wall, with the joists sitting halfway into the wall, meaning they only have about 4 inches of bricks to protect them.
If the wall is getting a lot of rain bounce, water will penetrate through to the timber quite quickly. Ideally the joists would be better on sleeper walls, or joist hangers.

 

[FBIBURTON]

Picture 2 - what's on the other side of the air brick? Is it still open and unobstructed to the outside? What about the others?
Is it just earth on the ground beneath the floor?
What looks like droplets of water in your photos - are they droplets of water?
The very wet floor joist - is that on an outside wall? (The wall with the patio on the other side?)

The outside its about 2inchs above the slabs,so there not covered. Yes it's seems like earth under the floors. Yes there droplets of water. And yeah the wet joist ends are on the outside wall.

 

[FBIBURTON]

Hi Andy,
Sorry to say it but that's not damp, its positively and absolutely wet and what you would see as a result of a leak from a water pipe or a collection of water - above or below ground -lying against an external wall and fining a way through it to the interior. Best guess at present is that the recent heavy rains are part of the problem and that poor drainage from the slabbed path and beneath it are the root cause. As joists are getting extremely wet this can lead to rot and wood-boring beetle infection that will ultimately cause the floor above to fail. If you can, try to localise the probable the site(s) external sources of the water and investigate under the particular slabs. Look specifically for places where the DPC below the apparent level of the base of the joists has been breached.

Well when we first moved in we had electric problems, we had an electrician find that a splitter box was wet, but it was when we had snow. A few weeks later I checked and there seemed water underneath the house, I knew I had a soil pipe a few feet away so I did a Di flush. Turns out the Croc soil pipe 2 ft underground had a crack and it was leaking water, but no smell which is strange. That's dry now though.
So you think lift the slabs and start digging see what's going on?

 

[FBIBURTON]

It looks to me like the DPC is only half a course above slab level, when it should be at least 2.
It also looks like a solid 9 inch wall, with the joists sitting halfway into the wall, meaning they only have about 4 inches of bricks to protect them.
If the wall is getting a lot of rain bounce, water will penetrate through to the timber quite quickly. Ideally the joists would be better on sleeper walls, or joist hangers.

Yeah it has no cavity, and your right about the dpc height. What do i do as a quick fix first? Quite stressed about this.

 

[Zebra]

Can you lift those slabs? Are they yours?

 

[FBIBURTON]

Hi, I'm going to cut 8inchs from the house, dig out 8inches below the dpc then top up with 2inch of lime stone gravel to start off with. Then monitor. Maybe put a water seal on the brickwork? What you all think?

 

[Cubist]

Well when we first moved in we had electric problems, we had an electrician find that a splitter box was wet, but it was when we had snow. A few weeks later I checked and there seemed water underneath the house, I knew I had a soil pipe a few feet away so I did a Di flush. Turns out the Croc soil pipe 2 ft underground had a crack and it was leaking water, but no smell which is strange. That's dry now though.
So you think lift the slabs and start digging see what's going on?

Yes, the amount of water that appears to be getting indoors suggests a problem that can only get worse, and much more expensive to fix, if it is not dealt with.

 

[stuart45]

Yeah it has no cavity, and your right about the dpc height. What do i do as a quick fix first? Quite stressed about this.

Not sure how quick a fix you want, but the best method is to find out exactly what is causing the issues. Damp can sometimes come from more than one source.
Looking at the joists ends there's a fair chance that one source is moisture penetrating the brickwork into the joists pockets.
One method may be to sit the joists on hangers, and fill in the pockets with brickwork.
The first 2 things though would be to lower the external ground level, and check for leaking pipes.

 

[88v8]

After you lower the ground, and perhaps take the joist ends out of the wall which was bad design from the start, underfloor ventilation is your friend.

Do you have airbricks front and back?
That terracotta airbrick has a very small open area. I would replace it with cast iron. Nowadays they're so easily available new, I wouldn't bother looking for an old one. Paint it with a full oil paint system before installation.

In each room, there should be at least three airbricks, and if there is a wall between front and back, there should be openings underfloor so air can flow through.
Stick your head down with a torch, and look. A builder who is capable of a bodge like building joists into the wall is quite capable of omitting ventilation openings, but at least that's easily fixed.

Don't stress if the wet does not immediately vanish. A wet wall can take a month per inch of thickness to dry.

Ivor