LadyBuilder

Ok, the place is big but that is essentially bigger rooms rather than millions of actual rooms... I might be just overconfident, but I reckon I can do myself... just seems like tedious, rather than complicated work

Hi, not sure where to post this, so please move or let me know if wrong I am looking for someone to do the M&E design and I am getting quotes of £6k upwards, which seems extremely expensive. Can anyone recommend/suggest anyone reasonable? Thank in advance!

Segmented like 50p. The quote in the original post is Nudura. I assume if they had something to suit they would have suggested it. starting to think it is best to just do ground floor in h+h solid wall with thin mortar and kooltherm

Thanks everyone for this. Has anyone used the one-series or the spider tie formwork that was posted in the basement forum

Hi, I am trying to figure out what to do with my bay window detail. Advice from Nudura has been: 'I note that there are a couple of ‘detailed’ bay windows and I have suggested using our 45 degree corners for this profile but as each of those forms would need to be cut to fit the design then there would be a lot of waste. It mat be possible to form this detail in a different way and thus save a fair bit of money. ' Can anybody suggest alternatives? I am thinking H+H blocks with thin joint for example, but I am worried about the connection detail and air tightness.

Thanks for this! I see now how they fit in. Unfortunately I do not agree with you, they do increase the width. I believe you use a bigger block, because otherwise you end up with of 50mm concrete which will have no load bearing capabilty

Nudura explained that their standard blocks have a U-value of 0.24. To get down to 0.15, they have an 'insert' of another 100mm EPS, which somehow slots in the formwork (awaiting the actual details): ' The estimate for the 0.15 U Value uses 250mm core with 100mm inserts giving an overall unfinished wall width of 387mm. '

Here is a question that has been bugging me... We are looking to achieve 0.14-0.15 wall U-value, as air tight as possible If we choose ICF for the house structure, the overall thickness of the wall ends up over 430mm thick including brick slips and plasterboard, because of the 100mm insert. What if we were to use the one series by Nudura and dot and dabbed K5 Kooltherm insulation (e.g 100mm) to the concrete side, similar to a EWI? That would reduce the overall thickness of the wall. What am I missing? Do you think it is a clever (although more expensive) way around it or am I forgetting something crucial? Any other innovative ideas? We need to clad the house in brick slips...

I just figured what the question was... My basement is a lot bigger than the house on top, have a look at the plans. So I'd never be able to prevent cold bridging that well, or at least I haven't figured out how to yet Proposed house levels.pdf

and frankly concrete likes wetness/damp... as long it is not in the room and contained

I don't know, is the honest answer...all the basements I have seen (which is only in London) have the insulation inside My logic would be that the cold and hot air meeting inside rather than out may just result in condensation/damp, but then membranes are always installed as standard by all the builders I know

I uploaded the plans in my third or fourth post. Not sure how to post as pics, only have pdf cheapest sip quote is appr 120k, icf is 24k but then I am not sure how to price all the other components: joists, roof, etc all of my quotes aim for around 0.13-0.15 U-value any idea how much the other stuff is for a cube that is 330 sq m?

For WPC I am getting £180+vat/m3 just for raw material, hence my reluctance to use. I am not so keen on Newton products, I prefer Delta, but I find Newton's techical drawings very good As I mentioned a few times, I am very keen to try shotcrete, got a £125+vat/m3 for raw material quote, but no formwork for the walls, so no worry in terms of bursts etc and considerable saving in terms of labour In terms of insulation, I'm so far thinking of either 200mm EPS/XPS (still researching if XPS worth the extra money) or 100mm PIR (CA4000)+ 50-60mm screed for the floor (gives me 0.11 u-value) and 100mm PIR (0.15 U-value) for the walls. Not sure how the PIR will be on a moist concrete floor, though I know people (builders) who swear it is absolutely fine I am tempted to put the bentonite and keep it without any membrane for the next 5-6 months, to see if any leaks. Then only do the membranes and perimeter drainage if necessary. the best quote I've had so far for MVHR is 10k for materials only. Your price is amazing! Are you ventilating every room or just wetrooms? I had a quote by panasonic for ASHP and they recommend 2 units (I asked them to quote for heating&cooling), I have to go back and ask why 2 units, it wouldn't make snse to need one unit for each component. I got a really good quote from a polish company for timber sashes (appr £700 a window), in previous jobs I've heard of nothing cheaper than 1.5k. So my thinking is that if air tight/triple glazed units cost 2k for example, it is better to get the polish and just use more heat... I've got something like 17 windows....

You are absolutely right, CIL is £214k... Got the cil exemption on fri, commencement notice sent yesterday.. spent most of today getting warranty quotes as i cannot get a self build mortgage but you are wrong, I still haven't got a clue what I am doing... so many options, so many pro and cons - frightening. some I've done before, some I've only read about and most of all a lot of things seems to be put in place as 'insurance', hence you never know if you need it or not, e.g. 2 forms of water defence - are drain cavities and membranes needed or just 'in case' water comes through my piling is 'in case' the excavation collapses metal deck for ground slab, supposedly safer than formwork etc etc

I have actually spoken to the basement guy who did the first bit... ages ago when I was doing my first basement. I did it with my guys (luckily, judging from the show) I also spoke to the competent replacement, but all the quotes are in the region above.

Ha ha, I do have plans... but there is still quite a lot of space that I don't know what we'll do with. I live in Nappy Valley, so one idea is to create a birthday party venue for children as there is nothing similar around, but my husband is not keen... We decided to build as big as we can, as adding extra basement afterward is not cheap. 3 kids, loads of relatives from overseas... you never know

Essentially, I don't mind where I put the insulation, above or below. I will not be able to use bentonite if it is below, so then I have to use WPC, which is more expensive than the bentonite

My london clay has been deemed unsuitable for infiltration suds, hence the permission to join the combined sewer. We are on a slope, so I expect surface water from above in an area classified as 'critical drainage' by the council Interestingly, I was reading that ground source pumps and they draw heat from the soil. There is a significant diffrence between the surface temp of soil and the temp 3m below. a study was done to show that when surface soil temp is 2.5 degrees, 3m below is around 11.5. That leads me to believe that less insulation is needed in basement slabs vs ground slabs and generally heat loss at basement level is not the same issue as at ground level

They are not very unskilled, I just could not guarantee that there will not any hairline cracks in a 72m long perimeter wall 3m high (which ideally should be done as stage pour) basement is is the games, guest room, gym, etc so I prefer to have heating. given it's size, I might turn it into a kids birthday party area i my husband ever agrees

I have to have a sump for the lightwells anyway, as the combined sewer is above basement level. I might getaway with the foul pipe running above the slab or in it (not very keen) but given the span, no way for the lightwell

I will contact Sika to get a price, but the prices of WPC here like Caltite etc are almost double to other concrete. Which in my case would would out to an extra £35k roughly

we encountered water at 3.5m but this is deemed as short term standing water and most likely perched water sitting at the top of the London Clay i am still not certain what is the benefit of having the insulation under the slab vs over. the basement will not be used a lot, i am thinking it is better for the ufh to not heat the slab given it size. I want to be able to heat the rooms quickly, rather than use a lot of energy to warm up the slab for only a couple of hours use every other day

Just been reading your posts re basements. it appears that you had a lot more room than me. Being in Central London, space is at a premium, so I am piling on the boundaries. This essentially means that even the formwork needs to be one-sided. Hence my interest in shotcrete... I hear lots of talk about WPC, but my worry is that it is only as good as the people doing the formwork/pour. Using my guys, I don't believe I would be able to guarantee the quality. Using anybody else will be giving away a lot of money (self build in london means 'i'm rich&stupid and I am looking to find someone to rob me blind') Had quotes for the basement box only!!! (not waterproofing or services) between 400k and 600k here is a birdseye view of basement plan 17127-PL.01-P1_Basement_Plan.pdf

Good point, this is how I ended up on this forum actually... researching under or over slab insulation. At this point my thinking is insulation on the inside. I did this last time and worked well, but would be keen to hear people's opinions of efficiency of insulation. This method allows me to have the bentonite as type A and then the membrane as second form of defence. Opinions?

I have a 3200sq feet basement that I have no idea what to do with, so plenty of room for any plants :-) (Yes, have a plant room planned) I am not familiar with Kryton, will do some research. I used this one my previous basement: http://www.premcrete.com/solution/maxi/ I'm also adding the plans as always useful to hear knowledgeable people's opinions DR 02_BASEMENT PLAN.pdf DR 03_GF PLAN.pdf DR 04_UPPER FLOORS AND ROOF.pdf