Rising damp or lateral ingress?

JT1987LBN

I recently purchased a bungalow, on the survey we were advised that it had a rising damp problem. The picture below shows an inspection hole we made to the exterior wall of one of the bedrooms, showing water is getting into the property which has got progressively worse the longer it rained. Please note there was no signs of wet in the inspection hole when the weather was dry for a few days. Internal walls show no sign of dampness. Before we call in local damp experts, we're looking for advice on the next steps we should take to help identify the problem. The external path around the house seems very high, should we cut a drainage channel? Thanks in advance.

FreeBear

Some photos of the outside would be helpful.

If the DPC is bridged by external soil levels, then it needs to be reduced. Ideally, around 150mm below the DPC. Installing a French drain in combination with ground level reduction will also help. A French drain is just a trench about 200mm wide filled with gravel.

neilmcl

You haven't got rising damp, actually there's no such thing, you've got water penetration from an outside source so you need to discover where the source is. Is that pic from the exterior or the interior? A wider shot for context would be useful.

JT1987LBN

Thanks for the quick replies! Shown below are pics of the outside and a wider angle of the bedroom. The bathroom and breather pipe for the toilet are located between the two bedrooms. We discovered a leaking shower which we hoped was the cause but after fixing that it rained and our investigation started again. We cleared all the gravel and started clearing the moss off the path (before it rained)

Apodemus

I wonder if the outside concrete isn't so much a path as a previous attempt to stop water ingress?  I have that in a couple of places and it is a false step.  It might be better to remove that and either lower the ground level or install a french drain as mentioned above.  Next time you get heavy rain it might also be worth looking to see if you are getting water splashing back off the concrete and up the wall.

Incidentally, I had a couple of external pipes very similar to the small one coming out of the wall nearest the camera.  These had been added about 20 years before for a bedroom sink and for a dishwasher.  On checking, I found that the plastic had completely degraded on the lower surface, to the extent that it was possible to push fingers through the plastic.  So it might be worth checking the condition of this pipe, both inside and outside the property if possible.

neilmcl

If it rains is there anywhere for the surface water to drain off or does it just sit there against the wall. How close to the damp area is that soil pipe? I can see some discolouration of the wall beyond the pipe, what is that from?

stuart45

Did you notice any debris in the cavity when you opened the wall up? If the cavity is clear well DPC the water shouldn't get through to the inner skin.

JT1987LBN

As you look at the outside picture, first on the left is the front bedroom - then the bathroom - then the rear bedroom. Both bedrooms show the same water ingress signs. I cant tell if its the same in the bathroom, but that's next on the list to rip out.
Other than the gravel strip on the right there is no other drainage. I will check the pipe as suggested and I'll cut a chunk out of the concrete path next to the wall to see whats going on underneath. Next time it rains I'll check where the water is going and post with an update.
Thanks for all your help

Doozergirl

I can't really see where your damp proof course is, but the position of the toilet waste is low to the ground.  Does that actually go into the back of the loo?  It would suggest that the concrete is very high to the DPC.  

Is the DPC obvious on any other area of the house?  You can then follow it around and see exactly how high that concrete is to it.  

The damp earth only needs to sit against the wall to start penetrating it.   Just removing a small section in the hunt for evidence isn't going to bring much up.  Find the damp proof course, and that will tell you if it's the concrete path that is the problem.  

JT1987LBN

Doozergirl said:

I can't really see where your damp proof course is, but the position of the toilet waste is low to the ground.  Does that actually go into the back of the loo?  It would suggest that the concrete is very high to the DPC.  

Is the DPC obvious on any other area of the house?  You can then follow it around and see exactly how high that concrete is to it.  

The damp earth only needs to sit against the wall to start penetrating it.   Just removing a small section in the hunt for evidence isn't going to bring much up.  Find the damp proof course, and that will tell you if it's the concrete path that is the problem.  

I might need a little bit of help with finding it if you can please? The survey states that "The external walls contain a poured bitumen damp-proof course" what would I be looking for?
Yes the pipe does go into the toilet via a long waste tube - soon to be removed as we are re-modelling the bathroom as part of the renovations. 

stuart45

Look for a black line in the bed joint. You might see it just below the door frames.