Who to approach about rainwater ingress.

[JAG]

A 1970's bungalow. We have rainwater ingress above dampcourse level to the extent that the room is becoming uninhabitable. To the average DIYer there are no obvious entry points where the water can enter. I want to get a professional in to deal with the problem but who do I contact. It seems to be beyond any local builder - and it seems outside the scope of companies dealing with condensation.

[RobLe]

Stick a sheet of clear polythene flat up against the wall.  If the issue is condensation, you will get condensation forming on the room side of the polythene.

Perhaps water is getting into the cavity, and puddles on the dpc, slowly leaking in?  Is it in one spot, or all around the room ?

[ProDave]

Post some pictures of the affected area both inside and what is immediately outside at that point.

[Redbeard]

As ProDave says pics would be good. I'd be looking at height of dpc above surrounding ground level, typical 'splash-up' height in the area (look for 'tide-marks' on neighbouring properties), 'softness' or 'hardness' of the surrounding ground. Have you been in long? Was it fine for years and now isn't? Have any other 'building circumstances' changed recently?

[markc]

All of the above are good points, as you say it is rainwater ingress I presume this only happens when it’s raining? Or is it just damp walls? Or a or more damp rooms?

 

[Radian]

Do you know if your cavity walls are filled with insulation material?

[Marvin]

Hi @JAG

 

Also, roughly where in the county are you?

 

IF, you have cavity insulation and driving rain this can cause this sort of problem.  We have a 1970's timber framed bungalow but with no cavity insulation, however we decided to paint the outside becaue of the driving rain. My mum's bungalow with cavity wall (brick and block) has cavity wall insulation and had problems from driving rain....

 

Good luck 

 

M 

[JAG]

Thank you for your prompt replies. The property is part of an estate in Bedfordshire, flat chalky ground, slightly at the top of a hill but nothing exceptional. I bought it new about 40 years ago but do not know if it has cavity insulation. The wetness is worse in winter suggesting it is rain - but it is always there. The soffits and tiles are all in place. The wetness occurs in one outer corner of a bedroom, and the outside wall shows signs of moss growth below DPC. The wetness appears mainly as small trickles from behind the skirting and mainly above the DPC. The problem has been developing for probably four or five years, firstly as a mild damp patch but now more serious, and there has not been any building modernisation in that area of the property for a decade.

My thinking is that rainwater is leaking into and settling in the cavity but I cannot find from where - everything seems OK. I have drilled a number of weep holes but nothing shows. Water services are all on the far side of the building. 

I am confused and want to find a professional - but who ??

[saveasteading]

5 hours ago, JAG said:

It seems to be beyond any local builder

It requires understanding the structure and how water moves, and most little builders just build.

It is good that they have declined rather than meddled.

We recently had some very poor proposals for a basement....a specialist who does one thing only, right or wrong.

 

So you need the right builder, or Architect, or Building Surveyor. Keep looking, but it has  to be the right person who totally understands.

There is always an answer, and it is often simple to resolve, but let us help first with those photos.

And also, how long have you lived there, how long has there been a problem, and do you feel that it is it closely linked to rain?

 

in my experience, it is usually to do with a covered damp proof course,  and often from ground levels being built up.

[JAG]

 

[Radian]

Is that a rain-chain?

[Conor]

Start by digging out all the mud and replacing it with clean stone. And what is the down pipe draining in to? A gully or just the ground?

Edited December 5, 2022 by Conor

[saveasteading]

My immediate thought too. Never a great idea.

JAG good pic. Can we have another showing up to the gutter, and another the other direction.

[JAG]

This is a photograph of the corner - for some reason printed twice. It was taken this morning after a couple of hours gentle rain and you can clearly see that the wetness of the green mold has already crept along. You can also see the DPC but the water ingress is above this. The downpipe goes to a soakaway but this is clear - and the chain is just decoration. To the left you will see a channel I cut in the paving in the hope of finding an open hole but no luck.

[JAG]

Radian, the chain is simply a support for the clematis you can see at the base.

[Radian]

It could be that there's debris in the cavity left over from when the house was built. Very easy to fix on a corner. Take out a full brick on the side wall that spans the cavity at DPC level and poke around inside. If you're not up to removing a brick, it's a limited job you could ask a tradesperson to do. But it should be straightforward enough for anyone to do with a hammer and masonry chisel.

[markc]

Where is the DPC? I can’t see it. And/or where is internal floor level compared to the outside

[JAG]

[JAG]

This is the top of the corner. The right hand corner is identical and has no problems

[ProDave]

The path along the side looks to be less than the recommended 150mm lower than the DPC so you will be getting some rain splashing on the wall above DPC level.

[JAG]

[JAG]

This is the overall picture of the left corner. You can see how far the damp has crept in just a couple of hours in a morning. There is a DPC about two bricks up from ground.

[Radian]

Which of these is where the DPC is? I'm guessing the red line:

[saveasteading]

To avoid jumping to conclusions, More questions.

Where inside the house is the worst of the damp? relative to this picture.

I don't see a change jn the dampness between the pictures. Where and how far has the dampness increased today?

Does the trench at the bottom ever fill with water?

 

Any bricklaying experts there? the wider mortar course seems very wide to me, even if it includes dpc.

Is it normal to have such a thick joint, and also to point over the dpc? 

I wonder if this bed has been removed and redone, as the trowel work is pretty shabby, as are several joints below dpc.

 

JAG, as an intermediate remedy, can you divert the downpipe to flow onto the garden? If the paving runs down from the house then that will do it. If the paving runs towards the house then that is something else we need to know.

[Jilly]

Do you know exactly where the soakaway is located?