Hi there JennyC. I can probably be of only limited help here, as I'm not a professional. But, as you've stated, it sounds like the problems we were trying to overcome were similar.
We also specified that we wanted no piers and luckily we were able to get away with it. The structural surveyor said the deciding factors were that (1) we were within the distances required for having a return (or is it buttress), to argue that the next wall running parallel to the wall we were removing was giving enough stability to the remaining outside wall. (2) We'd checked the condition of the brickwork (removed plaster and exposed it) and it was solid and we'd checked the depth of the foundations. (3) We'd used appropriate (as per his specs) padstones. So we ended up removing several walls and got away without needing any piers/arches etc. Neither do we have any cracks/problems some years later.
As for the digging a hole bit - I'm pretty sure that there was never a hole dug in the sub floor. I dug at least one hole outside next to the outside leaf of the wall. Depending on the type of foundation you have, I can't see why the foundation under the outside leaf would be any different from the inner leaf. Maybe that depends on the type of construction of your house though. Normally with brick houses, the foundation trench is dug as one, the concrete poured and the below dpc courses built on top, both inner and outer leafs. My understanding is the inner leaf is the one bearing all the weight from the house (although it would spread this to the outer through ties and other connections), so again depending on the type of sonstruction I'd think it unlikely/uncommon/questionable if it's built straight off the concrete slab.
All of the questions you've asked here should+could be answered by your structural engineer. Sometimes you just have to demand that they get their boots on, get over to your site and get their hands dirty!
Best of luck, let us know how it goes.
We also specified that we wanted no piers and luckily we were able to get away with it. The structural surveyor said the deciding factors were that (1) we were within the distances required for having a return (or is it buttress), to argue that the next wall running parallel to the wall we were removing was giving enough stability to the remaining outside wall. (2) We'd checked the condition of the brickwork (removed plaster and exposed it) and it was solid and we'd checked the depth of the foundations. (3) We'd used appropriate (as per his specs) padstones. So we ended up removing several walls and got away without needing any piers/arches etc. Neither do we have any cracks/problems some years later.
As for the digging a hole bit - I'm pretty sure that there was never a hole dug in the sub floor. I dug at least one hole outside next to the outside leaf of the wall. Depending on the type of foundation you have, I can't see why the foundation under the outside leaf would be any different from the inner leaf. Maybe that depends on the type of construction of your house though. Normally with brick houses, the foundation trench is dug as one, the concrete poured and the below dpc courses built on top, both inner and outer leafs. My understanding is the inner leaf is the one bearing all the weight from the house (although it would spread this to the outer through ties and other connections), so again depending on the type of sonstruction I'd think it unlikely/uncommon/questionable if it's built straight off the concrete slab.
All of the questions you've asked here should+could be answered by your structural engineer. Sometimes you just have to demand that they get their boots on, get over to your site and get their hands dirty!
Best of luck, let us know how it goes.
