Damp wall and timber floors, surveyor report

[JohnD]

Suspected no dpc.

Who does, and why?

Ground level higher than floor makes it much more likely that the DPC has simply been breached. Forget about chemical nostrums until you have lowered the ground level, added drainage, and waited for the wall to dry out.

If that coating is bitumen, it won't stop water getting into the wall (from underneath) but it will prevent it drying.

 

[Alex H]

Because it's 1920 solid wall and it wasn't usually installed then. This is the only wall where ground level is at or above the floor level.

It's just paint on the lower part, but I understand what you are getting at.

 

[Nige F]

I'll hope it's just a thin layer of concrete.

I'm minded to remove the path entirely and not put it back (it's not a right of way).

Disposal will be fun as the biggest thing I can get to the front would be a transit style tipper.

Are you in an ]agricultural area ? Quite often farmers can use hardcore

 

[wessex101]

I just wanted to flag up this "1920's hollow concrete block construction" as most of the replies seem to be based on it being a solid 9 inch brick wall.

I looked at something similar in Wiltshire last year. You probably need to establish the exact construction as there are a number of non-traditional system built houses from that era. The one I looked was an ex MOD (War Department as was then I think) house, it was very damp and suffered from horrendous condensation due to the construction. I decided it was a money pit and gave it a wide berth. It had a DPC but it had been bridged by the external render and external ground level, there were also possible issues with damp coming up through the floor as well as penetrating damp as it was riddled with cracks.

 

[Alex H]

Yes, it's not solid wall but concrete block with no cavity.

Bar this one wall the timber throughout that I'd exposed was in good condition, and the woodchip throughout, which is probably older than me is clinging well to the walls.

It's just this one cold wall with little sunshine and a raised path.

It's a sheltered coastal location and the ambient temps don't usually drop too low.

The kitchen/utility annex is damp, but it's single skin block un-insulated. I'll need to strip that back and insulate walls/roof.

There is a lot of work to do here, but it's a long term project with a view to retiring down there in the future. Plus it's got amazing views and it's own parking space.

 

[John D v2.0]

Because it's 1920 solid wall and it wasn't usually installed then. This is the only wall where ground level is at or above the floor level.

It may well be true, but building "regs" as was, where followed, even then required some form of dpc.
Our house is 1920s rendered brick, and everywhere has several layers of slate dpc embedded in lime mortar.
As we all know, slate doesn't make a continuous damp proof layer, but it does slow the moisture down.
A lot of people with non visible slate dpcs are under the impression it's either missing or failed, but in reality is as adequate as it ever was.
Usually it's changes such as the raised ground levels implicated here that can be resolved to fix the issue, despite the fact that the dpc was never perfect even where it did exist.
Injection damp proof course can certainly help the performance of slate dpcs or other imperfect ones, but other less invasive solutions can be followed to bring things back in balance.
Not knowing the exact op situation I can't say how much applies to them, but it's hard to be certain about 100 year old construction without investigation!

 

[John D v2.0]

I'll hope it's just a thin layer of concrete.

I'm minded to remove the path entirely and not put it back (it's not a right of way).

Disposal will be fun as the biggest thing I can get to the front would be a transit style tipper.

I'd remove it as you suggest if you can. Disposal is a one time problem, then you can enjoy your dry house!

 

[d000hg]

I have a related question I'll save raising a thread for if possible...

Old houses were just built to BE damp - you'd have rising damp even with a raised floor, and just had to deal with it. But how do your wooden joists and floorboards cope with that? Because it seems they do - they can easily last a century seemingly, when fitted into brick which can be pretty wet.

 

[stuart45]

Many of the old houses I've worked on with timber floors and damp problems had rotten floors.
Houses of 100 years ago normally had DPC's under the plates and joists.

 

[d000hg]

Sure they rot eventually... but they were damp from day 1 and seemed to last pretty well.

What kind of DPCs were used back then - and when did this come into effect?

 

[stuart45]

2 courses of slate was normally used. 1875 seems to be roughly the date when the DPC was brought into the regs. Floors can have rotten plates for years before anyone notices.
In the UK most people had solid floors until more recent times.

 

[d000hg]

Interesting. My house is ~1860 but was built to a high spec (mine manager's house). I've yet to inspect under the floorboards so I'll be interested to see a)if it's rotten b)if there is any form of DPC.
Of course it has had renovations so the joists butting up on the wall with the damp may have been replaced previously. Or if we got lucky, the joists go the other way so none of them touch that wall!

But even things like panelling and skirting boards commonly used to hide damp - would these typically rot and get replaced periodically?

 

[stuart45]

Apart from floors, panelling was well known for having a load of dry rot behind it. This does not mean that it applies to every house of that era.

 

[flameport]

excavate a narrow trench and fill with gravel so that it drains away. Presumably requires somewhere for the water to go

Definitely requires somewhere for the water to go - otherwise you just have a water filled trench against the wall and that will be far worse than the path.

get that downpipe away to a small soak away,

From the picture, that seems very unlikely - soakaways must be located far away from any buildings, typically at least 5m, often more.

 

[Alex H]

That down pipe serves the front half of the roof, plus part of the side. I'd hoped it was just the side.. the soakaway would be a lot bigger than I'd initially thought.

Noted I don't think I'll get the required offsets to my building or adjacent retaining wall.

Currently the water runs from the path to front of the house, down steps and onto the road. There isn't much in the way of surface water drains round here in a tightly packed Cornish harbour village.

I may have to consider altering the guttering and getting that water to the rear, where the combined sewer is. Even if for now it's an unsightly couple of water butts with an overflow to the sewer.

I've just noticed the rear kitchen annex also has a Down pipe straight onto the rear yard, which is at least shaped to funnel water to a drain, but I think I'll put a yard gully there too. As it's damp around that down pipe too.