Wall doesn't reach the Ground!

[sherburn]

Was happily chipping off old bits of plaster etc in preparation for applying a damp proof membrane having already pulled up a rotten floor our surveyor helpfully decided not to draw our attention to before we bought the house, when I suddenly realised I wasn't exposing wall any more, but instead was into the limestone/clay bedrock the house is built on!

The wall generally seems to start around 6 inches above internal ground level, looks like someone in the past has dug out the floor to below the level of the walls? I've included a couple of pictures, one showing what looks to me like the base of the wall, and the other showing the material I scraped out of the area circled in red on the first picture with my fingers- it's pretty squidgy in there!

No signs of movement and the ground level to the rear is around 1.5metres above the internal ground level, and I'm wondering if I should just cover it up and forget about it, or if I really need to bit the bullet and spend money I don't have getting experts in to look at it.

Thought I'd post it here in case anyone else has seen or had anything similar, and if so what did you do?

Cheers

Red line shows base of wall

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• sherburn
• 19 Oct 2011
• 1

Scooped by hand from red circle in above picture:

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• sherburn
• 19 Oct 2011
• 1

edit: in case it's of any interest, the house is apparently 150-200yrs old, of stone/rubble construction, walls approx 1.5foot thick

 

[JohnD]

lots of old houses have poor (or no) foundations.

If it hasn't fallen down yet, it might stand for years to come. But you are moving into Underpinning country here. It can probably be done by excavating small sections as bays, and filling each with concrete before starting the next one, but with your stone and rubble construction, I think you are going to have to consult a structural engineer or a building conservator for reliable advice.

My BIL had a similar job in his historic cottage, and did it himself, but he is an accomplished builder, and used the conservation department of his local authority, and historic buildings association, for help and advice. He also had a lot of attention from Building Control. He is in Australia so not the same organisations as here. IIRC his "foundations" were trenches filled with Bluestone rubble, possibly packed with lime mortar. Time, long-term water-leaks and burrowing rats had weakened them

 

[sherburn]

Thanks for the reply John, I probably should get someone in to look at it, but after some thinking, and seeing as money is so tight at the moment I think I'll probably just patch up the small section I've exposed and leave the rest alone. Then when it all falls down I'll come back here and you can say I told you so!

I figured that seeing as there has been no movement, as long as I don't disturb the ground around the wall (which was the original plan- dig a small trench to fill with rubble for the DPM), it should be fine for now, and be ready to call the experts in at the first hint of any movement.