Posted: Wed May 03, 2006 11:41 pm
Hi,
thanks for a great website. I've made a start at leveling the sub-grade for a new patio, but have a dilema over what the paved level should be. The house is circa 1890 and does not appear to have a DPC, is fully rendered on the rear walls, and seems to suffer from rising damp around the kitchen walls.
The ground level has been lowered by some 10-12 inches, exposing the top level of the stepped foundations, which coincides with the top edge of the salt-glazed gully (or p-trap?).
While the lowest 12 inches of render is missing pending a tidyup, I am contemplating injecting a DPC. If I do this below the suspended floor level, it will be around the level of the top of the foundation. Obviously this does not make it 150mm above what is my lowest paving level (i.e.. the top of the drain.) I don't think the gully/p-trap can be lowered. The connection is directly underthe foundation, heading off somewhere under the kitchen.
As the side of the kitchen was once rendered down to a long narrow concrete slab that drained into the gully and no DPC has ever existed, is it not my best solution to install a DPC, continue the render to the foundation and install my paving sufficiently high to facilitate adequate drainage (linear drain?) away from the walls, ensuring that render and paving together make a watertight seal?
Would also appreciate advice on the drain, which sits as low as the base of the foundation on what I believe to be chalk. There's no concrete bed or haunching, just a surround of sodden clay. I think the clay is so wet because the orginal concrete slab leaked around the top of the drain and allowed the water to soak down. The brick mortar is in poor condition in this vacinity and the floor joists are damp. Should/can I get an old salt-glazed drain tested, and should I create a more stable bed?
Just to make this post a little longer...We intend to lay 12-15mm ish slate. One of your listed suppliers suggest that a concrete base be laid over hardcore, then a full mortar bed laid down as the slate goes down. I read in your archives that you suggest laying a 75mm concrete base as the slate goes down (or have I misunderstood?) I know which I'd rather do, but need to be confident that it's of sufficient strength for such thin paving. We're terraced, so all agregates have to be carried through the house.
Any advice welcome.
thanks for a great website. I've made a start at leveling the sub-grade for a new patio, but have a dilema over what the paved level should be. The house is circa 1890 and does not appear to have a DPC, is fully rendered on the rear walls, and seems to suffer from rising damp around the kitchen walls.
The ground level has been lowered by some 10-12 inches, exposing the top level of the stepped foundations, which coincides with the top edge of the salt-glazed gully (or p-trap?).
While the lowest 12 inches of render is missing pending a tidyup, I am contemplating injecting a DPC. If I do this below the suspended floor level, it will be around the level of the top of the foundation. Obviously this does not make it 150mm above what is my lowest paving level (i.e.. the top of the drain.) I don't think the gully/p-trap can be lowered. The connection is directly underthe foundation, heading off somewhere under the kitchen.
As the side of the kitchen was once rendered down to a long narrow concrete slab that drained into the gully and no DPC has ever existed, is it not my best solution to install a DPC, continue the render to the foundation and install my paving sufficiently high to facilitate adequate drainage (linear drain?) away from the walls, ensuring that render and paving together make a watertight seal?
Would also appreciate advice on the drain, which sits as low as the base of the foundation on what I believe to be chalk. There's no concrete bed or haunching, just a surround of sodden clay. I think the clay is so wet because the orginal concrete slab leaked around the top of the drain and allowed the water to soak down. The brick mortar is in poor condition in this vacinity and the floor joists are damp. Should/can I get an old salt-glazed drain tested, and should I create a more stable bed?
Just to make this post a little longer...We intend to lay 12-15mm ish slate. One of your listed suppliers suggest that a concrete base be laid over hardcore, then a full mortar bed laid down as the slate goes down. I read in your archives that you suggest laying a 75mm concrete base as the slate goes down (or have I misunderstood?) I know which I'd rather do, but need to be confident that it's of sufficient strength for such thin paving. We're terraced, so all agregates have to be carried through the house.
Any advice welcome.