I'm adding a conservatory to the back of my house.
The builder says they'll dig 45cm, and if they don't find suitable ground they'll dig up to 75cm before pouring footings. That makes me wonder, what would be the definition of "suitable ground"? How will they know when they're deep enough?
(Anyone experienced in this will immediately realise that I've never dug below ground in my life - I know about as much as any man-in-the-street who peers into a hole to see what the Gas Board's doing!)
- Tim
Footings - what does "good ground" look like? - How deep is deep enough
-
Mikey_C
- Posts: 952
- Joined: Mon Oct 30, 2006 8:24 pm
- Location: Bournemouth, Dorset
Being a bit like yourself “not having performed a great amount of hard landscaping� 
I recently wanted to put a boundary wall up, internet searches provided no clear idea of how far down I should dig, no calculations that could be made, a general opinion was that the base of the footing needed to be below 450mm for frost protection, having tried to 7 structural engineers (5 said they were to busy, one said he would return my call and never did, one quoted a £1000 pounds and required me to dig two test holes) the 8th told me I would find a “nice gravel bed about a meter down� and having been swing a shovel like there was no tomorrow I struck said “nice gravel bed� and knew straight away what he meant, as soon as the shovel starts bouncing on the ground you know you can build off it!
Hope my experience helps!!
Mikey C
I recently wanted to put a boundary wall up, internet searches provided no clear idea of how far down I should dig, no calculations that could be made, a general opinion was that the base of the footing needed to be below 450mm for frost protection, having tried to 7 structural engineers (5 said they were to busy, one said he would return my call and never did, one quoted a £1000 pounds and required me to dig two test holes) the 8th told me I would find a “nice gravel bed about a meter down� and having been swing a shovel like there was no tomorrow I struck said “nice gravel bed� and knew straight away what he meant, as soon as the shovel starts bouncing on the ground you know you can build off it!Hope my experience helps!!
Mikey C
-
lutonlagerlout
- Site Admin
- Posts: 15184
- Joined: Fri Aug 04, 2006 12:20 am
- Location: bedfordshire
if they hit chalk thats great time ,BC in luton have let us build off rock chalk only 500 in the ground in dunstable.
clay realistically they need to be 600 deep
any built up ground must be removed
there are no regs for conservatorys so they could build off 300mm dig but i would ask for 600mm by 450 mm wide,in real terms this is 3 spits of the fork
hope this helps
LLL
clay realistically they need to be 600 deep
any built up ground must be removed
there are no regs for conservatorys so they could build off 300mm dig but i would ask for 600mm by 450 mm wide,in real terms this is 3 spits of the fork
hope this helps
LLL
-
MatthewWakeman
- Posts: 70
- Joined: Sat Jan 07, 2006 9:38 am
- Location: West Midlands
In the west mids building inspectors like to see solid clay and then build at leat 150mm out of the ground for frost protection on at least 500mm wide 300mm deep footings but it does all depend on ground conditions if its bad listen out for rafts and ring beams etc etc. what you want is a nice cheap straight forward strip footing
regards
matthew
drivewaycompany.co.uk
regards
matthew
drivewaycompany.co.uk