Plinth wall ledge versus ground levels

[tobydog]

It's fairly clear that both the internal floors (concrete) and the outside ground levels of our house have risen over time. They are, however, generally level with each other. I want to reduce the ground levels, particularly in the areas where the plinth has not been totally encased in cement 3ft below the ground :roll: (I'm not sure what lowering the ground in these parts will actually achieve).

Whilst investigating what I actually have down below, I noticed that the plinth wall seems to sit on a brick base that steps out by half a brick width. It's like a ledge. I've seen in some books that this is quite common, however, whereabouts (in terms of ground level) should this ledge be? It's currently about 6" below ground level in the area I want to improve. Unfortunately, now that I've opened up the area right next to the wall, I've noticed that the modern bell drip on the cement render runs directly into this ledge. If I dug down further, would there be another ledge?

Thanks

 

[DJH]

If I dug down further, would there be another ledge?

Thanks

Unlikely Toby but quite possibly. That's no help I know but at a guess you have brick 'footings' which again is good if they are hard bricks that don't absorb water but on the downside if they are bedded in mortar moisture will soak right through to inside the property maybe below your concrete floor. You don't say if there's a dpc under the concrete but I guess you'll have to keep digging to investigate if there's another ledge or not.

Good luck with it.

Doug

 

[middi]

If there are no "foundations" as it is understood in our modern era, the chances are that (as you have already seem to have found out) a " spread" system foundation, as it was sometimes common, which consisted of a gradually outward spreading brick wall plinth of various height directly on a mortar bed. Your main objective, regardless of shape, size, or depth of plinth must be to ( initially) lower the ground level to below internal floor level and the " bell" drip of render is not touching the outside ground level.

Middi

 

[Penners]

Is this wider brick base the bottom course of the plinth? If so, you absolutely should not dig down below it.

 

[tobydog]

I haven't dug down any further yet but I'll try a bigger exploratory hole. On an outside wall which is actually inside the old lean-to type utility, the first step is only a few bricks below the sole plate. On the outside of the lean-to it's several inches lower than that. This is the one I'm enquiring about because this is where I will start lowering the ground levels. As I mentioned above, most if the house plinth is encased in cement 2 - 3ft into the ground so it's the few areas that aren't that I'm more concerned about. The house is 1640 timber frame and the lean-to is old but added later.

On going through some photos looking a suitable plinth shot (I didn't find one) I found a photo of our inglenook. Not bad eh for a two bedroomed cottage :shock:

 

[DJH]

Very nice Tobydog.

 

[Penners]

I found a photo of our inglenook. Not bad eh for a two bedroomed cottage

You're right. That inglenook would make a very nice two-bedroomed cottage.

 

[tobydog]

:lol: That's a great thought Penners. I was starting to worry about how I was going to house the family and outlaws at Christmas.

 

[Penners]

My consultancy bill is in the post.