New build Basement... project managing help !

[newbie29]

Hi Guys

Ive made some great contacts on various forums,and as crazy as it sounds decided to project mange my basement.
A basement contractor has kindly offered me one of his contacts, his past employee has recently set up on his own business and is able to provide me a labour price for the shell, or fixed if I wish, my only reason for going labour only is on the hope of saving a few bob

-His team-
3 guys 1)under pinner 135 a day 2) labourer 85 dat rate 3) himself---site supervisor multi skilled 170.
Decided to go down the traditional route underpinning the existing house, constructing the basement retaining wall in 1m segmented sections around the perimeter of the basement.

Waterproofing will be sub contracted out to a specialist firm who are able to offer a warranty, I cant afford to keep the place so will need some kind of warranty when I come sell it.

At the above labour only prices nearly 2k a week, im looking to get started in 2 weeks, bad time of year to start a basement :0( I know.
Before I agree a start date, would it be fair for me to ask them for a guide to how long they think it will take, my thoughts so far shortest time frame with no issues 16 weeks, max with issues 20 weeks.

I wouldn’t be onsite everyday as I have a 9-5 m-f slave driving job, these are my current thoughts on helping me keep tabs on the site, what do you guys think?

1)I’ve setup 2 cctv cameras with live recording , to help me monitor start times, general progression on site by the minute,

2) The basement build is being carried out in 1m segmented strips, I could work out the average time taken to complete 1 strip and use that in order monitor there progress.

3) Qs would the contractors stop working in rain & bad weather and still charge me the full day rate?, as taking the time of year I could be asking for trouble, contractor says his guys worked until 20th dec last year on a basements builds.

Great to hear your thoughts the good the bad and the witty!

[B17NNS]

Why don't you just ask him for a quote to do the job with him providing you a list of materials and the dates they are required on site?

[GT03ROB]

You are right you are crazy.

You are project managing yet you appear to have neither schedule, plan, decent estimate, contract or detailed scope of work. Please ensure you have clarity on all of these before you do anything. Asking here won't achieve that.

Good luck by the way

[andy43]

Yeah, go for it.
Just one word that worries me though - underpinning.
You need a structural engineer's design, people who really really know what they're doing digging under your house, and most importantly an insurance backed warranty for the work from these people or similar - http://www.asuc.org.uk/ - if you ever want to sell your house.

Underpinning in 1 metre bays will allow the water table to push water through the joints into your basement, so any slurry or stick-on damp proofing will need to withstand the pressure. Oldroyd membrane and a sump would be better.

Y'know those 'your house may be at risk' notices they have on mortgage applications? Self managed underpinning may also fall into the 'house at risk' catagory in a whole (hole) different way
You need a building control man there. A lot.

GT03ROB said:

You are right you are crazy.

[Busa mav]

Have you made sure you have any party wall agreements in place , given you are 2 weeks away from starting , if you haven't , you can forget the start date.

Have you got building regs approval and a proper structural engineer engaged ?

Have you considered what insurances YOU need to cover yourself , as you will become the employer / main contractor.

Those day rates seem extremely competitive given you may be in Middlesex, if things start to get tough , or they get a better offer , they will clear site before you even know it.

I assume you have no on site experience, if so , you are not mad , but bloody insane

Edited by Busa mav on Friday 12th September 21:00

[Spudler]

Busa mav said:

I assume you have no on site experience, if so , you are not mad , but bloody insane

and soon to be a whole lot poorer.

[Steve H]

It's not entirely clear to me what you are intending to do but if you are using an internally shuttered underpinning to form the walls of the basement underneath the existing building then I have some experience in this and would be happy to answer any more detailed questions on here or by PM.

[C Lee Farquar]

andy43 said:

Yeah, go for it.
Just one word that worries me though - underpinning.
You need a structural engineer's design, people who really really know what they're doing digging under your house, and most importantly an insurance backed warranty for the work from these people or similar - http://www.asuc.org.uk/ - if you ever want to sell your house.

I've been supplying concrete to a new basement extension this week, and see quite a few of them. Most have serious cock ups, either shuttering shifting or design/construction issues resulting in indoor swimming pools.

The less split accountability you have the better and FFS don't clock watch, the underpinning needs to be done right more importantly than to a rigid timescale.

The downside of getting things wrong outweighs any perceived saving you have for doing it yourself, in my experience.

[Slagathore]

£135 a day for an underpinner seems suspiciously cheap, even if it were cash.

And installing CCTV to check up on them is a good way to piss them off if you review the footage and then start asking lots of questions about why the left early etc. At those day rates, there's not much of an incentive to hang around if the client pisses them off.

The drawing looks pretty amateur, any decent trades will want to see proper drawings.

[vescaegg]

OP this is the worst idea ever. Like seriously.

Research this a lot more! Basements are the hardest things to do ever.

Get a proper company. It will cost you proper money though.

Do it wrong and your new games room will come with a free swimming pool

Edited by vescaegg on Friday 12th September 22:18

[AlmostUseful]

Basements are the devils own job, get somebody professional to do it. Seriously.

[newbie29]

Party wall awards have been drawn out, ive instructed green structural engineering for the basement design and temporary works.

What should scare me is every comment made is valid but im too excited to hand this over to contractor, my budget is also tiny :0( im a gambling man, will I be around to tell the story only time will tell :0)

Is basement building really that difficult with the aid of a –structural eng- & -experience basement ground workers- construct the retaining wall in 1m segmented sections around the perimeter of the basement, followed by rc slab, followed closely by a well-designed waterproofing solution, looking to go for the delta membrane system or something equivalent.

The team im using are running 2 jobs in central london both retro fit basements, im looking to go over and see each job early next week.

Thanks for offering to help with my silly Qs

Keep them coming its given me alot to think about, im going to discuss it with my pillow before i get some Zzzz in.

thanks again

[badboyburt]

Basement build on day rates ?

Open cheque springs to mind, cant they give you a price for the work, agree interim payments for completed works.

Day rate will just turn into a hospital job.

Good luck though, get some pictures up as they progress.

[CoolHands]

but cost wise its not worth it? As someone pointed out, build up into attic rather than down into earth. If you're on a tight budget it doesn't make sense. It will go over your 30k budget. And the you'll wish you'd gone up / not wasted 6 months doing it. You'd make more money doing a conventional new build quickly and sell, than waste 6 months in the ground.

[jules_s]

Get the structural engineers to design everything and supervise everything

[Steve H]

I do agree with some of the comments about getting a proper structural plan to work to, would be crazy to do it without that but getting the actual work done is really not that complicated.

I started off with an old barn




Pulled out the floor



Dug some holes



threw a bit of steel in



and shuttered them on the inside



then put some concrete in them



Part of the structural design had steel bars linking the blocks so they were tied together together



then we dug out the basement, you can see the steels sticking out there to tie the floor in and the sump for the drainage system



and the same view with the slab and membrane in, starting on the UFH





Started on 3rd Jan and everything except the final photo was done before the end of the month. Two labourers and one digger man, none of them had done anything like it before.

It's worth saying we had a few advantages.

Strictly speaking this wasn't a full basement as the finished level was about 1.5m below the outside ground level so a full underground basement would probably take another 1m or so depth.

We had plenty of space to work and were digging in dry clay so it was heavy work but didn't try to collapse on us.

It was January and it didn't rain for a single day!

[dxg]

newbie29 said:

Party wall awards have been drawn out, ive instructed green structural engineering for the basement design and temporary works.

What should scare me is every comment made is valid but im too excited to hand this over to contractor, my budget is also tiny :0( im a gambling man, will I be around to tell the story only time will tell :0)

Is basement building really that difficult with the aid of a –structural eng- & -experience basement ground workers- construct the retaining wall in 1m segmented sections around the perimeter of the basement, followed by rc slab, followed closely by a well-designed waterproofing solution, looking to go for the delta membrane system or something equivalent.

The team im using are running 2 jobs in central london both retro fit basements, im looking to go over and see each job early next week.

Thanks for offering to help with my silly Qs

Keep them coming its given me alot to think about, im going to discuss it with my pillow before i get some Zzzz in.

thanks again

As the owner of a building that's currently subsiding I was worried, but not too worried until a Building Surveyor friend of mine commented "It's not just the risk to yourself that you've got to think about, but your liability to your neighbours." That struck the fear of God into me...

Perhaps that's something to mull over.

[jamesc_1729]

Steve H said:

I do agree with some of the comments about getting a proper structural plan to work to, would be crazy to do it without that but getting the actual work done is really not that complicated.

I started off with an old barn.....

Steve - do you have a full build thread anywhere detailing the remainder of the barn build? Looks like a great project.

[Terminator X]

No contract, no fixed price, no end date Could take forever and cost the OP a kings ransom!

TX.

[Steve H]

jamesc_1729 said:

Steve - do you have a full build thread anywhere detailing the remainder of the barn build? Looks like a great project.

It was fun, an interesting build to do but we did it start to finish in 9 months while holding down a full time and a part time job so didn't have time for threads, sorry