Damp Rising Up Through Floor Or Ingress?

[philly1]

Hello, I'm after some advice on a damp problem in my house and hope someone here could help? I'll try to be as descriptive but brief as possible!...

I bought a 1950's bungalow last year which is on a hill and one of the bedrooms at the back (up hill) has had a damp smell since we moved in and decorated. Eventually took the new laminate flooring up and there was damp in between a lot of the old floor tiles underneath (see photo). I have since taken the tiles up and painted a layer of Wickes liquid damp proof over the bitumen adhesive that was underneath and it now looks pretty waterproof! However, I'm not entirely sure if the damp is rising up through the floor (because of water migrating down the hill under the house maybe?), or whether its more likely to be coming in through the walls somewhere? There were patches of damp on the floor along the external walls, but not really a lot more than the rest of the room and the walls all seem fine. I notice the external has pebble dashing all around apart from on the bottom two bricks, not sure why? However, on the back wall of the damp bedroom, this layer of brick has been cemented over (see other photos). Would this have been done to try to stop the damp problems maybe? Would it be a good idea to paint some water sealant for brick over these parts? The same wall of the bedroom has also been replastered quite recently by the looks of it (where i've stripped the wallpaper in the photo).

Am I overthinking this/worrying too much!? Any advice would be much appreciated.

Thanks, Phil

 

[theprinceofdarkness]

That pic with the line of bricks in it. I reckon that your damp course is lower then the path and a bodger tried to fix it by putting a bit of render on it. The problem is that the water will run down hill between the path and over the damp course showing up as the wettest spot at the down hill end. I would lever off some of that cement to locate where the DPC is. Cut the path back 2" from the wall and dig out a groove so water from the path can drip down into the soil (throw a bit of gravel in to pretty it up). Follow this around the whole building. You may find that the DPC suddenly steps down some where, but the path is on a slope so its higher then the DPC.
Frank

 

[philly1]

Hi Frank, thanks very much for your reply. I've had another look at the bricks and just underneath where the pebbledash finishes and the bare brick starts, I can see a black slither all the way along which I'm assuming is the damp course so this is above path level and is around the same level as the floor inside. I will hack off a bit of the rendered section to see if there is a step down in the damp proof on that side like you suggest. I have attached a picture of the house so you can see the path and the way the hill is running, the affected bedroom is the window on the right. Next door is obviously on a higher level and the grass does get quite a bit boggy on that side so I'm thinking it probably is more likely that its rising through the floor than coming in anywhere? I haven't noticed any damp smell in the bedroom next door though (also on the high side facing next door), so it's a bit strange how it is so bad just in that room. Is that amount of water coming up serious or am I worrying too much do you think?

 

[philly1]

Should also add, there is a fair bit of water coming through the wall from under next doors drive every time it rains - see photo (this is just behind the bush in the last photo, at the corner of the house - you can just see the corner of the path at the bottom in this photo). I am channeling the water away using a french drain/land drain which goes across the lawn and out onto the path by the gate, but guessing a lot is still being soaked up in the soil. I dont really want to bung this hole up as I'm guessing it will just build up and make its way out somewhere else where i cant keep an eye on it?

 

[theprinceofdarkness]

WOW! you have a stream running towards your house. If the DPC is intact then water will not rise through the brick work, but if the high water level is leaving a large puddle within your walls under the house, the water will constantly being evaporated and when it hits the more or less waterproof bitumen glue/PVC tiles it could condense into real water again and mark the floor boards.
First thing is to make sure that all your gutters and drain pipes work properly, no point adding to the water overload. I think the next thing is to pull up a floor board and have a look. If you are unlucky, your floor joists will be rotten and will need attending to. One thing that has not been mentioned are air bricks, are there any?.
I know of a bungalow built on a hill like your one. The back garden is about 5' lower then the land at the front. They have knocked a door through the back wall and use the void as a cellar. The only problem is with the lower back wall, its damp and you can see water bead on its inner surface.
I once worked in a premise that was on the top of a long ridge, near one end. The land fell away 100' from the front and the back, 100' at one side, BUT there was a slight rise (20'?) along the ridge for 1/2 a mile or so. Every time it rained the water table rose to within 18" of floor level due to an underground stream which ran along the major length of the ridge, despite having a huge drop to the sides. Perhaps your underground water flow is more in line with this curious scenario.
Frank

 

[ree]

philly1,

Ignore the bizarre blather above, if you follow that kind of technically ignorant guesswork it will cost you dear.

You need expert opinion on site. You need this expert to detail in writing what must be done.

Here is a number to an Independent Remedial Surveyor of many years experience. He is regarded as probably the most knowledgeable expert in this kind of work in the UK. He has written the text book for professionals.

Graham Coleman: 01747 840 715 or 07885 765 142 He is an independent remedial surveyor only, he does not contract or recommend contractors.

Call and talk to him for a free heads up.

Your building plot has been cut into the hillside (possibly below the water table) and your damp difficulties are not going to go away.

Dont lay any laminate flooring, and strip back the wall paper to the plaster on the affected walls.

FWIW: why wasn't this business picked up on the mortgage survey? Its patently obvious to anyone with an ounce of experience in this field.

 

[stuart45]

Quite a common problem with 50's homes that had concrete floors in areas with high water tables such as where I live. Most of them didn't have a DPM which became part of the Building Regs in the 60's.
However a site visit as suggested by ree will probably be the first step.

 

[philly1]

FWIW: why wasn't this business picked up on the mortgage survey? Its patently obvious to anyone with an ounce of experience in this field.

I paid 700 for the more detailed 'home buyer report' and no mention of damp... not to mention the woodworm infestation in my loft!!

In fairness though, there was no sign of damp on the floor tiles when I was renovating and it was the wettest February on record! I think because there was no covering over it the moisture just evaporated away. Only other thing I can think of is we had cavity wall insulation put in since then and all the vents blocked up so maybe that is causing issues

Thank you all for your advice it's much appreciated, and thank you ree for the number. I may see how it goes now that Ive painted the liquid damp proof membrane on first though and if it comes back at all then give the surveyor a ring - haven't had great experiences with them!