How much should this cost builders?
Discussion
I'm building extension on my workplace and have asked them to do something extra. This extra is a courtyard 4 meters wide and 3 meters deep with double doors off of the basement part of the extension they're building. The basement floor is about 2 meters below ground level and so the courtyard would have to be excavated to the same depth.
The ground part would just be gravel and would have a retaining wall around the 3 sides in breeze blocks with render.
The excavator is still on site.
How much extra should this cost?
The ground part would just be gravel and would have a retaining wall around the 3 sides in breeze blocks with render.
The excavator is still on site.
How much extra should this cost?
W12GT said:
You are looking at circa 50T of muckaway.
What is the ground like? Clay/chalk/made ground full of rubble? What is access/egress like for waste removal? Do you have a set down area for a grab lorry or will it be by skips? Can a topper be used or will it be by wheel barrow?
It will need temporary works to support the excavation. You WILL need building regs approval for the retaining wall and foundations so you will need a structurally engineered design. You will not be able to use the blocks you mentioned as they will just crumble away. You need dense blocks and the wall will require a decent foundation - assuming this is 11m linear wall and 2m high. You will also need drainage as it will literally become a swimming pool due to how far down it is - I am guessing a pumped system with a float switch.
Due to the height you will also need to have safety barrier/wall to prevent falling. Do you needs steps out of it?
Are there any buildings within 3m? Are you within 2m of your boundary? If so consideration needs to be made on the risk of undermining existing foundations - you may also need a Party Wall agreement.
Sorry for such a long list but as you can see it isn’t a straight forward thing to price.
Great points, thanks!What is the ground like? Clay/chalk/made ground full of rubble? What is access/egress like for waste removal? Do you have a set down area for a grab lorry or will it be by skips? Can a topper be used or will it be by wheel barrow?
It will need temporary works to support the excavation. You WILL need building regs approval for the retaining wall and foundations so you will need a structurally engineered design. You will not be able to use the blocks you mentioned as they will just crumble away. You need dense blocks and the wall will require a decent foundation - assuming this is 11m linear wall and 2m high. You will also need drainage as it will literally become a swimming pool due to how far down it is - I am guessing a pumped system with a float switch.
Due to the height you will also need to have safety barrier/wall to prevent falling. Do you needs steps out of it?
Are there any buildings within 3m? Are you within 2m of your boundary? If so consideration needs to be made on the risk of undermining existing foundations - you may also need a Party Wall agreement.
Sorry for such a long list but as you can see it isn’t a straight forward thing to price.
This is exactly the same as has already been done for the existing project which is 150M2 going right up to the boundary on 2 sides. So its an extension of an extension of you will.
Access good for waste removal which is by dump truck. Ground is somewhat sandy but with high organic content so is not slumping. No rubble as it's never been excavated before. There is already a 12 ton excavator on site.
The breeze blocks I'm talking about are being used currently for the basement build so I'm assuming they're up to it! They're hollow and being fitted around the metal rods and filled with concrete as they go.
Foundation is planned and the retaining wall is three sides of a square with 2 sides 3 meters and the end 4 meters long.
Drainage with pump already planned and the pipe is in place ready to accept a drainage grill.
Safety barrier planned, party agreement signed.
magooagain said:
From what you describe I would estimate at least eight days for a finished product with that amount of workforce.
Excavation of hole and foundation. Muck away.
Set out for steelwork. Steel into foundations and upright steel installed.
Concrete foundations and create drainage for behind retaining walls.
Ringbeam?
Layblocks and insert steels at the same time.
Fill blocks with liquid concrete. Lay copping stones and attach railings.
Render walls.
Prepare and install all drainage. Prepare surface area
Membrane and lay shingle.
I've missed out loads of small time consuming bits and bobs.
Hello mate, so what you reckon, 10, 15?Excavation of hole and foundation. Muck away.
Set out for steelwork. Steel into foundations and upright steel installed.
Concrete foundations and create drainage for behind retaining walls.
Ringbeam?
Layblocks and insert steels at the same time.
Fill blocks with liquid concrete. Lay copping stones and attach railings.
Render walls.
Prepare and install all drainage. Prepare surface area
Membrane and lay shingle.
I've missed out loads of small time consuming bits and bobs.
magooagain said:
Ten to twelve days without any bespoke requirements. It should help with them being on site allready.
Is the digger digging from above? Can they get the muck directly into a lorry or does it need moving by dumper first then loaded?
Lots of things to consider.
No, I meant £K lolIs the digger digging from above? Can they get the muck directly into a lorry or does it need moving by dumper first then loaded?
Lots of things to consider.
Yeah digger is on site and can dig from above straight into lorry.
magooagain said:
I gave it some more thought last night.
I reckon there will be about an extra 12 ton of soil to come out as it needs to be at least 20cm deeper than the back of the block work,so back filling can be carried out correctly.
They may price for a skim of waterproof render on the back of the blocks also,it's bought in bags and just mixed with a plaster mixer. Or the might lay a membrane against the back of the blocks. Both widely available in France.
Then a gravel backfill.
There should be weep holes at the bottom of the walls to let out any water build up etc.
Good shout, they’re going to use Delta MS same as in the rest of the build I reckon there will be about an extra 12 ton of soil to come out as it needs to be at least 20cm deeper than the back of the block work,so back filling can be carried out correctly.
They may price for a skim of waterproof render on the back of the blocks also,it's bought in bags and just mixed with a plaster mixer. Or the might lay a membrane against the back of the blocks. Both widely available in France.
Then a gravel backfill.
There should be weep holes at the bottom of the walls to let out any water build up etc.
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