I am sorry if this posts 3 times. I keep getting an error report when i try to submit. Please delete where appropriate.
I don't have an existing roof. What I do have is brick and mortar walls. For reasons too long and complicated to go into I can't spend money on trusses, roof sheeting, tiles etc. Such a roof would have to be at least double pitched because of our wind factor.
I am considering a near flat sod roof. I understand that I will only get absolute confirmation from an SE but frankly, that's not going to happen. My husband doesn't want to (for the same reasons not mentioned above) spend large amounts of money on external inputs. Besides which, I don't think any structural engineer here will bother. "Too much effort, why don't you just put a galvanised roof back on?" There are no such things as "free" or "cheap" seconds in South Africa, there is too much demand and we are 150km away from any decent sized community where we could possibly find such things. We will still have to drive 150Km to the nearest salvage place just to source doors and windows. Having just fixed up a temporary dwelling onsite I am well aware of local resources or lack thereof. So it's going to have to be something cheap that two people can manage. And we're not shy of hard work!
The house was built at least 60 years ago. It was vandalised about 8 years ago and the roof removed. The original roof was corrugated iron-still the old heavy stuff, I have a few samples that were not carted away.The walls are in good shape and the floor is solid, no cracks or subsidence. I have tried to attach a diagram, hopefully it works and hopefully it's clear. We have a
concrete slab of 10m X 11m. Foundations are at least 50cm below ground and the cement slab is 30cm above ground. The outer walls are cavity walls and the inner walls are single. We dont have enough resources to build cover the entire slab so we want to do an "L" shape and use the rest as a patio. We will have a large pile of dirt right next to the house from the cellar excavation and "gravel" in the form of broken clay bricks and mortar. I was hoping to use either builders plastic or 600g PVC pond liner. My layers would be poles, galvanised mesh
fence, 30cm
straw, plastic, then either membrane, 5cm gravel(draining to a down pipe via drainage tile), 12cm soil.
or just 15cm soil with about a meter width along the roof edge of gravel with drainage tile linked to a down pipe.
Most sod roofs I have seen are either reciprocal or double pitched. What I would like help with is:
1)Overall suitability of the project
2)Do we need to re-inforce the single walls and will a round pole post and lintel "wall"work?
3)Do we infill the cavity walls or insert an additional post and beam or leave as is?
4)Thickness and spacing of poles
5)Can I
cob the ceiling?
6)Will there be lateral force on the walls where the thinner walls will want to lean towards the thick wall because of the weight and therefore collapse? One one wing the slope will be towards the cavity wall and the other wing will slope away from the cavity wall.
I seem to be having problems attaching an open office doc so I shall have to figure out a way to upload diagram.
I look forward to any comments relating to the build and anyone with pictures or experiences to share.