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I have just been on a call with him and he feels that even with a 140mm block supporting the hollowcore, he wanted to add in steel frame support. He has gone away to look over the calculations. We could use a 140mm block and tie it into the concrete wall.

Yes to forms of waterproofing...sika in the concrete and then a sika membrane under the slab and on the exterior walls. I agree there is no tie back to the concrete walls from the blockwork. I think he just sees the concrete wall as useable and far superior than the block, which it is really isnt it. Its just the cold bridge it introduces by splitting the insulation. The SE has suggested we increase the concrete wall to 350mm to support the block and beam. I think we will end up going with the SE's preference and dealing with the bridge in the insulation it introduces.

My architect said its a better idea to have the insulation internally. If we have insulation externally we have to bring the tanking further up the wall so the termination detail of the tanking would not be as good. He said we need the insulation to meet the SAP calcs. So, it either has to go inside or out and the preference was inside and then to run that void basement to 2nd floor as per the images. I get your point though as thats what I said to him as I wanted to avoid all the internal perimeter blockwork

Hey, would really appreciate your views on this one! Looking for thoughts on structural support for block and beam on a new build with basement and the various preferences from my designers Basement: 300mm concrete walls, internal cavity with insulation, inner leaf block, plasterboard Ground floor upwards: outer leaf brickwork, cavity with insulation, inner leaf blockwork My Architect wants an unbroken insulation zone from the basement to the roof, and to make this happen the block and beam to ground floor will sit on the inner leaf blockwork built up from the basement 300mm slab. We will also have block and beam on the 1st floor, so again the block and beam will sit to the inner leaf blockwork. Architect's request: My SE instead wants to shift over the block and beam so that the inner section of the 300mm basement walls provide structural support for the floors, rather than the blockwork as shown above. This is going to introduce a bridge to the insulation layer. The SE said if we use the above approach he wants to install steel posts and beams to support the floors above. SE Preference: If we didnt have a basement, and still planned to use block and beam, the beams for the floor would sit on the inner leaf of the block wall anyway. Just because we place a basement wall in does not mean it then has to be used to support the beam/hollow core floor? When we get to the 1st floor we have another block and beam, and for this we have no option but to sit the beams on the inner leaf block work. Which option should we go with? Thank you

How did you install the steels? Was it direct pile drive or did you dig with an auger and fill with concrete then drop in the steels? King post walls do offer more support than sheet piles from the designs I have seen

I am pretty much at that stage my self now. Having had the usual surveying and demo quotes its crazy how varying the prices come in!

I had demolition quotes ranging from £12k to 21k initially, then one guy came in quoting 7.5k. For the dig, work out how much spoil you have to remove in tonnes (https://www.source4me.co.uk/calculate_excavated_spoil.php), and then work it out to £100-150 per 16 tonne wagon load out. Then figure out how long it will take your guys on the machine to remove it. If your concrete team are expecting a hole ready to start with, why not get one team to do the demo and dig the hole, then another to come in and start the groundworks

When you work out what the materials actually cost then yeah it is expensive. I have done some high level material calcs for my basement. For 230sqm slab, and 210sqm of walls I am getting to around £65k in materials. This includes MOT, sika concrete, rebar, mesh, formwork hire. It does not include removing spoil, machine/scaffold hire. Obviously there are the additionals such as waste pipes, but thats rather inexpensive.

how did you put your job out to tender? Did you just send out your basement design to local firms after contacting them directly?

Hey Guys, I am just going through this now for my own project. We are planning a full footprint basement. My SE is in the process of providing the basement design, which will basically include basement and wall spec. My SI is complete and we have water at 1.5m so planning to dig trial pits once the house has been demolished to get a better idea on water levels. For waterproofing, I am not expecting my SE to provide this. Instead, I have liaised with Sika for concrete waterproofing, and they have referred me to CSSW approved tanking specialists. This approach will ensure the installation meets all warranty and build regulations. I looked at ICF, but it does not seem to be as good as in-situ cast concrete using formwork.

Hi, I am interested what the sump and pump was used for? Is this for taking foul back up to ground level or are you constantly pumping external water out because you are building in the water table?

Its sand sub soil with layers of peat in areas in the vicinity. The peat may not be on my plot necessarily but it has been found in the area. My ground investigation will confirm

Thats great Gus, yeah its not all about the haggle. Nothing in the building game is cheap, and often when you pay cheap you get cheap. Im all for a good balance and a great start with people on a job. I have worked with some younger lads who just burn out or dont have the heart in work, and some older lads who seem to love their work, and as you say....offer up experiences from their own previous portfolio. Its great when you find a good contractor because they are front of mind when the next job starts! I have used the same people time and time again.

Yeah it can become stressful. My father in law allowed a plumber to charge him a grand for what was 2 days work, fitting a couple of rads and flushing out his system. I only found out after he had it done. There are some real good contractors out there yeah, and its a shame of how many charlatans there are. One of the best guys I ever got in was a joiner I found from yellow pages. He said to me, I do every job as if it was on my own home. He wasnt wrong. Everything he did was absolutely perfect, and he was about £150/day

I have had to do the same myself with contractors in the past where plans were not available. On this occasion a plan with everything will be provided. I am not looking for people to give me the going rate as I agree it depends on the area and job. I am just outlining some experiences with people who come in with such varying price levels. I had one electrician a few years back come to my place saying he was £360/day. He didnt come back

hopefully youre right

We will have hollowcore concrete floors, but even so, might not take the weight of a 12 tonne machine. May need a large machine with good reach from the road.

Hi Peter, yes could always purchase and leave them in. There is an extractor that can be used to remove them. If they stay in, cost goes up as they are about 7k for 90x6m lengths

Thanks Adam, I will look into this too

That seems good value.

Access is straight in from the front. sheet piling will take place to the party wall, and the plot is getting up there for 1000sqm. Its a straight dig into sand, no services to worry about. Excavated material will be taken away on 16 tonne loads, managed separately but working with the team who do the dig. I agree its based on peoples interpretation so I always try to tell them exactly what Im expecting for the job so they can quote to the requirement.

Site investigation has to be done. At this point, with my knowledge of the ground, being all sand, and with a 3m basement dig, I estimated a minimum of 6m sheet piles. We may even have to go for slightly longer to get longer piles in the ground. Neighboring properties are not so much the issue given their location to our dig, but the party walls are. As I said in another response, we may even take down these party walls with agreement from the neighbours because they are not in the best condition anyway. fyi our site investigation will go down 6m, then potentially up to another 20m depending on whether peat is present. No corners will be cut on this one, only contractors that try and overcharge the going rate

Its to shore up up a 1mm party wall. The neighbours property is another 4 meters on both sides. In fact, we may actually take this party wall down and replace it, so there will be less load to hold back. Once we are back at ground level, we will place in new footings and build a new 900mm height wall

Hey guys, How much should I be looking to pay for approximately 30 linear meters of sheet piling on a supply and install hire basis. 15meters each side required on neighbour party walls We will then do a 3m dig, so I probably need 6m long sheets so we have a 50% sheet in the ground at least.

Thats more like it. Its 100% reasonable. When you start getting to £100+ per hour, its way over priced then. I dont want to pay cheap and get cheap, I want a job done well at a good going rate. Thing is....making 3k savings on jobs of this size 10 times on a big job and its £30k saved.