Period Ground Levels

[mattice]

I've had great success in drying out my back wall and an internal wall sharing the same small 3/4 height cellar by lowering the external ground level and ventilating with some air bricks. I intend to practice my lime pointing on the wall and foundations I've exposed. However I'm now stuck with what to do to reinstate the ground levels. Here's a picture (please excuse the mess, many projects in this picture!).

The ledge (it probably has a name) is mirrored inside and supports the internal floor timbers, previously the ground was a couple of inches above this in places. There is probably a further 3-4ft foundation below that already exposed so I'm relatively comfortable with my excavation. Whilst the soil is generally clay, in this area it's very free draining, I suspect several decades of ash have been deposited here.

I'm considering going down six courses, laying some 100mm deep footings, offset from the wall, and building a 4 course retaining wall topped in some blue bricks from the garden, effectively leaving a 200mm gap. This would create an evaporation zone with some membrane and large stones at the base. A lot of forums suggest putting concrete at the bottom of this and draining it away somewhere - this doesn't feel right. Even a French drain is proving difficult to fathom as I have a sewer to the septic tank running parallel to this wall acting as a barrier and all my surface water drainage is too high!

Is this a sensible solution? Does anyone have any other ideas for dealing with the ground level? Do I need to drain my 'evaporation zone' or can a rely on it naturally draining? I'll probably reinstate this area to lawn, or a gravel path. I've seen a previous post using crates where a path is butted against the wall but I'm not sure it'll work for this job.

On a related note, I've just started probing ground levels at the front of the house by two concrete slabs revealing a pool of water and some sort of brick structure underneath.... :shock: We have slate floors and I suspect the water is making its way through the wall and under the slate along the path of the mains water pipe, to an internal wall which is my last remaining damp mystery! Some pics for amusement before the sledge hammer comes out

 

[Zebra]

I made a gully with a retaining wall at the back of my house.

There's nothing in the base, and it drains naturally. There's only the bit of water that actually falls in it anyway. I don't find that any water seeps through the retaining wall into the gully. I haven't filled it with anything, there's just soil in the bottom.
It didn't actually solve the damp problems in my wall though, I ended up cutting in a dpc.

 

[mattice]

Thanks zebra, shame it didn't solve the problem. I dug the hole last December so I've been pleased to see a positive effect, although it's definitely been a combination of a few things. One of the previous owners sons who lived in the house 50 years ago can recall him cutting in a slate DPC around the entire house and it taking him the best part of the year. I've had a dig around but can't find it!

 

[LadyArowana]

Thanks zebra, shame it didn't solve the problem. I dug the hole last December so I've been pleased to see a positive effect, although it's definitely been a combination of a few things. One of the previous owners sons who lived in the house 50 years ago can recall him cutting in a slate DPC around the entire house and it taking him the best part of the year. I've had a dig around but can't find it!

Maybe lower down? not the sort of thing someone would imagine, well not unless they were very strange or mistook it for something else, but what?

 

[Lime]

I dug the hole last December so I've been pleased to see a positive effect, although it's definitely been a combination of a few things. One of the previous owners sons who lived in the house 50 years ago can recall him cutting in a slate DPC around the entire house and it taking him the best part of the year. I've had a dig around but can't find it!

I'd use a masonary drill to drill out small sections of the pointing (one on top of the other) to find it.
It isn't uncommon to have the slate completely pointed over with cement.

As for the space between the house wall and the new embankment wall, I'd make the space a little greater to enable clearance with a spade or similar.

 

[mattice]

Thanks Lime, I'll keep looking, and a spade width is a good idea.

M

 

[mattice]

Good progress with the ground level project, athough somewhat slowed by taking the hedge trimmer to my middle finger :?

As a result I've employed a builder to finish off my low retaining wall / gully. I had a great chat with him about old houses :wink: . He's definitely from the camp of Thompsons Waterseal, and suggested that his usual solution to high ground levels is to dig a trench, put some celotex against the wall and back fill with soil! He's never had a call back and far cheaper than going to all of the trouble I have!

I already have my hole dug, footings down and wall started so I'll continue as planned, however I wondered what people thought of his method

 

[88v8]

....that his usual solution to high ground levels is to dig a trench, put some celotex against the wall and back fill with soil! He's never had a call back and far cheaper than going to all of the trouble I have! .... I wondered what people thought of his method

If it's carefully done, and the membrane taken above the ground and pointed into the wall, then it would keep the water out, but, rising damp through the wall would be trapped all the more.
Assuming rising damp exists of course. :?

Ivor

 

[mattice]

 

[Bathman]

Interesting post, as I have some damp issues in my Victorian house and plan on reducing ground levels outside and also install some more airbricks to ensure good ventilation - so glad to hear this approach has worked for you.

Looks like you have made your mind up about how you are dealing with your gully, but I found a lot of useful information on this website about external ground levels and drainage, and plan on following one of these methods when reducing my ground levels: http://www.pavingexpert.com/dpc01.htm

The guidance on that website is that you should always try and install proper drainage of water rather than having water getting down the side of your house. You may be ok in your case, but where I get the damp in my house is on the wall which gets the full force of the weather, and if I put in any sort of gully without drainage it would soon turn in to a swimming pool when it rained. Which then means getting water going straight down to the foundations which could cause other issues

 

[MatthewC]

if I put in any sort of gully without drainage it would soon turn in to a swimming pool when it rained.

Hence your user ID?

 

[mattice]

Hi Bathman,

Yes this is still in the back of my mind and I've studied paving expert on many occasion, a great resource. I've had the (unfinished) gully there since March now, through some horrendous weather. The bottom of the gully is open to soil rather than cemented as in the paving expert and it rarely catches any water, even as it's North facing. I'm actually putting a perforated land drain on the soil side of the retaining wall at the level of the footings, on the house side I'm not going to back fill, other than some frost protection for the foundations but I'm going to leave an option to drain it into the land drain directly just in case.

The way I figure it is I've removed 0.6m of soil against my house, repointed completely shot pointing and large heave cracks and the whole wall looks visibly dry and happier! The now ventilated cellar at the other side of the wall looks far drier, although I have yet to venture down to fully inspect (access is a head first, rather brave, pot holing exercise!)

Once I've finished and survived some autumn weather I'll post a pic and sketch of the finished job.

M

 

[mattice]

Really sorry to keep revisiting my posts but I need some encouragement to move to the next stage :?

Back of the house sorted, just need to reinstate, nicely dried out, happy days!

You may remember this pic from the front of the house

I've lifted the mysterious slabs which were well above my internal ground level. External walls dried out nicely. No surprises under concrete but very wet (clay). Dug a test pit 800mm, filled up with around 100mm water.... I live on a hill, could this simply be retained by the heavy clay layer I hit? I didn't expect to find ground water :? The reason I'm concerned is that I have a tide mark that rises up an internal wall, not synched with rain necessarily and it is now worse than ever (even not as bad through the wet winter, despite my :?: improvements :? I've found my mains water pipe in the vicinity, uncovered it, looks OK.

The next plan is to dig a trench for a land drain along the front of my house leading to a gully which happens to be around 700mm deep, line with geotex, gravel, drop in a solid land drain (perforations up or down??), and top with gravel, hardcore and cold lay tarmac.

Having just re-read my post I just need to get on and do it. However if anyone has a new perspective
before the angle grinder hits the tarmac on Saturday it would be greatly appreciated. Why only this 3ft of wall and not the one nearer the outside, or indeed the external walls which all seem fine.

Here's a pic of the tide mark

And the context

Shame the damson gin takes a while

 

[mattice]

Just browsing posts from what seems an age ago but only 2 1/2 years since moving in. They read as frenetic and impatient. As we approach summer, the heating is now off, I'm struggling to locate any damp, the paint is flaking off because it's dry rather than wet, the salts on the wall just brush off, and the wet rotten skirting is now dry. The loft is airy, the house is warm and the so called cellar is draughty and free of white fractal organisms.

I've learnt damp is unlikely to be a single cause but is probably resolved with a bit of patience and a bit of muscle... and no gimmicks. Not rocket science, or expensive, and easily summarised as fix gutters, wait/think, lower ground levels, wait/think, ventilate spaces, wait/think, dig a moat around the house, wait/think, find a place to remove the water to, wait, victory... in my case.

You all know this, but it's a small celebration having had a dry winter and confirmed by the drying effects of the heating being switched off for a month.

Thanks. Patience and knowledge gained from this forum.

 

[88v8]

Hooray!
Frenetic... well, it's hard to feel relaxed when one's living in a damp house. And if you hadn't cracked on. it would still be damp.
But it does take a loooong time for walls to dry out.

Very satisfying for you to see a result.

Ivor

 

[Zebra]

What a great post. Yes, very satisfying to see a turnaround in events, and to have got to the bottom of things.