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We specced a hot return (it's in 15mm vs the main hot circuit of 22mm). Instead of using a pipe stat and timer, which was the plumber's default option, the sparky wired it into the same circuit as the MVHR boost which is activated when the bathroom light comes on or by a PIR in each bathroom - runs for a good 10 mins after each has been deactivated. We don't have any sensor in the kitchen, however there is a MVHR boost close to hand so I just hit that and presto - hot water

Just de-solder that one and extend it with a wire - should be fine if you mark the correct polarity.

Did you used to be in the A-Team?

Nope that's fine..! Got the height to get it in ..? Flanged tank connector (ABS one about £6-7..?) needs a couple of things. Drill a 115mm hole and try the backplate for size and mark the fixing holes - should be 4 or 6 - and drill those slightly oversized. Use some 5 min epoxy and bond some flanged nuts onto the backplate over the holes - makes life easy ..!! Straighten a coat hanger and feed it through the lid and onto the top hole of the ring of holes you've drilled. Two lines of silicone around the backplate and then slide the backplate into the tank along the coat hanger through the top hole - should all line up nicely ..! Two lines of silicone around the outlet plate and offer it up to the coat hanger ..! You can now reach through the open hole and align all the plates with 2 pan head machine screws. Do them up reasonably tight, then remove the coat hanger. Dob of silicone on the remaining 4 holes and screw them tight - remove the original 2 and do the same. Quick wipe round with with a cloth and as tight as a tight thing ..!

I have a basement as part of our new build, it is 11.5m x 10.5m and constructed as an 'open box' i.e no lid. Passive timber frame house sits on top, basement is passive also (fancy way of saying it sits on a foundation of EPS and walls are clad in EPS, meeting the outer leaf and insulated section of the timber frame. Three large 10m steels span the ground floor, (one on a post) with a web of smaller steel joists taking point loads from above and web joists in-between. We could have had a solid walls in the basement but wanted flexibility in the layout. Some quick comments on your plan. In my experience. the cost of a basement is dependent on a number of features. Getting planning is by far the easiest bit 1) most fundamentally - ground conditions. Tricky conditions such as made ground, hard rock, chalk (solution features) high water table etc will drive up excavation costs and construction costs. We have chalk under gravel (Thames valley river bed) so needed a very substantial slab (300mm) with lots of reinforcement. The only way you are going to know what the required basement spec is, is to have proper ground investigation (cores to 4m and probes to 10m) at 2-3 points in your footprint. You then need to have a SE work out the required structure, concrete, steel etc. You may get an early view on what's likely under your feet by searching for nearby historical boreholes to get a feel, but you'll ultimately need to do your own investigation as conditions can rapidly vary. Water table will dictate your degree of waterproofing. For us, water table was low at 6m so we were able to use warrantied waterproof concrete on its own. Our friends built near the Thames and needed external tanking and wp concrete (they used the Glatthar system, good but not cheap). Some opt for the internal membrane, sump & pump. Principal here is that you build a leaky box, allow the water to safely collect in a sump and continuously pump out. Very common on retrofit basements in London. Budget £5k for the investigation. If your LA adds requirements for contamination surveys etc then expect to pay a bit more. SE will vary, we paid £5K but got quite a bit of additional work in there too (services design etc..). BC will then want to ensure you have means of escape and/or fire suppression so external stairs or a sprinkler system will need to be in the design. Will you have wet services down there? If so, you'll need to pump wet waste up to the main foul level. How are the internals being lit? We used UPVC windows and GRP light wells from MEA - they've been very effective and the concrete team only needed to leave the aperture (sufficiently reinforced obviously per SE design). Party wall is critical also, we were lucky in that we escaped any notification due to the 45o rule. We were within 6m of one neighbour and 8m of another. Have you done any of this investigation & design yet? Pretty impossible to cost the job without it in my opinion. 2) Design - a simple rectangular box is cheapest, thinner the raft & walls the cheaper (subject to SE spec). Penetrations will add cost as they complicate the formwork and require more prep before the pour. 3) Access - a very tight site can be expensive to excavate, muck away and to get steel and concrete onto. You need min 1m working space, with appropriately battered back walls around the basement. If your ground is very soft or loose, you may need to sheet pile (very expensive). Our excavation (not much bigger than yours) required 73 20t trucks to cart away the spoil. Machine was loading them directly so it only took 3 days - we were lucky to have good access so this was not too painful. We also pumped concrete for the slab and used shuttered runs for the walls (pump hire is expensive) direct from the mixer. 4) Build method. ICF is a fine choice, especially if you're using an external or internal waterproofing method. If you're reliant on just WP concrete then you need an excellent pour with no honeycombing and this is impossible to confirm with ICF so traditional formwork is a better option. You can DIY your waterproofing but it will not be warrantied. We used a SIKA system which had admix in the concrete and the water bar between day joins - the SIKA rep came to site to inspect the work before pours and the team photographed everything as they went. So we now have a 20 year guarantee on the integrity, upon which the building warranty is dependent. Cost for our 120m2 basement (including demo of the existing and services) was £120k in Berkshire - probably £90-100k purely for the basement itself if you strip out the other parts of the package. We used a reputable local groundwork who brings in a proved team that did the steel, formwork and pouring - goes without saying that it's pretty skilled work. Good value for money in my opinion given the extra space that we acquired. Basements do not need to be scary but there is a lot of prep that you need to do before you can really understand and mitigate the costs. Fair to say that Tony (of Tony's house) did his own basement DIY at a fraction of my cost (he is an experienced builder of 30+ years) and I went to see it - very nice it is too. Probably plenty more to share on our experience if you have more questions!

Errr if you go with the big filter sock then the calming inlet is irrelevant. Tank 1 will be cloudy, tank 2 will be the better (overflow) tank 3 and 4 will be clearer as they should only get moved a little by water coming in and out of the 32mm connector. My tanks came off eBay from a place in Sheffield - sore subject as they are sat on a friends yard as the skip is still in the way so I can't get them in the ground ......

Correct although with a deck you could easily enable that ..! Dont forget the self cleaning ones dump the crud into your soak away - ideally you stop the big stuff at the gutter, smaller at the downpipe and the last bits at the tank

Might be. Here's the link to the interactive map: http://mapapps.bgs.ac.uk/geologyofbritain/home.html Click the top button "Borehole scans" and zoom right in at your location and you should see if there are any recorded nearby, and be able to read the drill logs if they've been made public, and if the driller filed them (they are supposed to, but ours didn't, I submitted the log to the BGS myself).

@JSHarris I wonder if it's worth @Carrerahill checking his location on your borehole link if you have it? I found two about 100m either side of the house I knew nothing about.

When I was a small boy, the house we lived in at the time had a large brick built air raid shelter in the garden. It was dug into the steep hill at the back of the garden, so was almost completely underground, except for part of one wall at the front, with a sort of labyrinth entrance (presumably to limit shrapnel getting inside). We lived around 1/4 mile away from the Martin Baker factory, which I would guess is why the shelter was built - Martin Baker may well have been a target during the war. A friend and I found the wreckage of a crashed aircraft buried in the woods nearby, and managed to dig up an old gun and loads of ammunition (around .303 calibre). the brickwork in the exposed wall of the old shelter wasn't in great condition, and we managed to make a small hole at a mortar joint, just big enough to stick one of the rounds in. The game was to stick a live round in the hole, then chuck rocks at it until we made it go off, with the bullet ricocheting around the inside of the shelter. Needless to say, the loud bangs attracted attention and we both got marched off to see the village policeman, and hand over all the ammunition we'd collected......

If you have 32mm then use that...! Those vertical filters are the wrong type, they are for downpipes. The horizontal one will work but its silly money - you can get them from Germany for about E85 or pick this sort up http://www.ebay.co.uk/itm/IBC-Rainwater-filter-Cover-filter-Lid-DN-225-Arch-89-DN-70-Reduction-DN-50-/112406930727?hash=item1a2bf9a527:g:n9QAAOSwYHxWPgJs IBC to 32mm are cheap enough - the ones with the tees fitted can catch on some of the deeper tanks http://www.ebay.co.uk/itm/IBC-ADAPTER-S60X6-2-Coarse-Thread-to-32-mm-Straight-MDPE-Compression-Fitting-/291687238158?hash=item43e9ea0a0e:g:3CcAAOSwll1WxKUe

Depends where you are but I have sourced 5 for £130 delivered (Sheffield) that have been used for food use and steam cleaned. IBCs have standard fittings which is a 63mm coarse thread - you can get these with a 25mm MDPE adapter already on them, and then with 2 tees between them you can connect all 4 together for about £40 of fittings and pipe. You will need a calmed inlet on the first one - I would put an ordinary 110mm low back P trap on the inlet and then take an overflow from an opposite one around 100mm below the tank top - you can do this with a flanged outlet (check Koi Carp suppliers for cheap ones..) and then the flow will be through a couple of the tanks. There is enough capacity on 25mm MDPE to take a lot of rainfall so don't worry about connecting with anything bigger than 25mm (unless you have some 32mm lying around...) Put the pump in the tank with no connections ie not the one with the inlet or overflow, and a simple 10" 5 micron filter between the pump outlet and the tap will mean you keep most of the crud out of the tap/hose.

Well I tried the Nick Knuckle test and I must have the wrong sort of knuckle!

I just tap with the back of my finger knuckle and use 'tradesman echo location'. People can't believe how accurate that is. .

(This post is a précis of a post and thread discussions that took place on the eBuild forum October last year and subsequent discussions with my builder.) Many of the self-builders active on the forum will have used or be familiar with the Passive Foundation system marketed by MBC Timberframe. The essence of this is that the foundation is a raft slab that incorporates a ring-beam that sits inside an EPS former. This former both acts as shuttering for the concrete pour and as insulation between the slab and the underlying hardcore base. The slab is therefore wholly contained within the thermal insulation envelope of the house, typically giving an overall U value for the slab of around 0.1 W/mK. So far so good. A variant of this is where the house has an external brick, blockwork or stone skin. In this case one approach is to pour a second outer ring-beam to carry the outer skin, and the MBC structural engineer (SE) Our skin is a rough-cut Cotswold-style limestone with an s.g. of around 2.5 (or 2.4 allowing for mortar); the walls are ~5m high, and the courses on average 125mm deep giving a linear loading of around 1.5 tonne/m rising to 1.8 on the 3 gables. The underlying ground is a very stiff impermeable (Oadby Member) clay, but We have some medium size tree quite near the foundations. Here is a simplified diagram of this. The SE specified bridging H20 rebars at 150mm centres to couple the inner and outer ring beams structurally, so that the load of the skin is carried across onto the main ring-beam and transmitted down through the ESP300 underneath the beams. If we assume that the load of the stone and house was carried only by the EPS300 sections of the slab, this gives an overall GBP of some 12 kPa and the 266 H20 rebars ensure that there will be minimal differential movement between the outer stone skin and the timber frame supporting everything else. This is comfortably within the allowable bearing pressure of 120 kPa recommended in the Geo-survey report. So this is a good structural design, but it unfortunately embeds a major thermal design flaw. If you consider the thermal cross section of the total rebar, it is pretty much the same (from a thermal perspective) as replacing the rebar and the EPS between the two beams by solid concrete. To be honest I along with everyone else missed this thermal design flaw when I was given a copy of the slab design to review. The penny only dropped for me when I saw the rebars in place, and the concrete was just about to be poured. The inner slab and ring-beam is within the insulation envelope of the house, but the outer ring-beam is at ground level and directly carries the stone skin. In the base design this would be fully exposed to the elements and could often drop to ~0°C or below in winter. The 266 × 2cm diameter mild steel rebars have a total cross-section of 0.084m, and this couples a slab at roughly 21°C with a ring-beam at roughly 0°C across a 20cm gap. This is a pretty perfect thermal bridge as steel has a thermal conductivity of roughly 40 W/mK -- this means that we will lose heat at roughly 21×40×0.084/0.2 W = 350W or 8.5 kWh / day in colder winter months through these bars. This is over 3 times the design figure of 2.6 kWh for the entire slab. Here is a small extract from the slab engineer's design. I've coloured the different components and removed a lot of the structural detail which isn't relevant to this discussion, so we can focus on the issue here. We were too late to change the design fundamentally, but if left uncorrected, this flaw would result in the slab being the single largest source of heat loss (more than the walls, the roof, or the windows and doors for example). So after discussion with MBC, Hilliard their SE, and members on the eBuild forum, what we decided to do was: We retained the outer EPS formwork that wrapped the outer ring-beam. This still left a thermal bridge between the top of the outer ring-beam and the stone skin it was carrying. Hilliard confirmed that a course of Perinsul Foamglas would be capable of supporting the design load of the skin and largely close the thermal bridge. However, we would then have an exposed ESP front and FoamGlass course edge which is cosmetically crap and vulnerable to rodent damage. So after discussing options with our builder we decided to cover the entire exposed EPS / FoamGlass surface with some courses in engineering brick. And when the skin was complete we would then put a perimeter path 60cm wide and 10cm (min) deep around the house on the crushed stone bed. Here is a simplified schematic that I drew up for my builder of the approach that we finally agreed on. What he did was to use two external courses of engineering bricks as an plynth in front of and on top of the FoamGlass, followed by two header courses to step back the wall line. This engineering brick wrapper is primarily cosmetic and a weather protection as the load is actually carried down vertically through the FoamGlass onto the ring-bean, I've also included a photo of the plinth at one of the rear French windows where you can see how it looks in practice. There is still going to be a little bridging on the diagonal between the ring-beam and the outer engineering brick layer, but my rough estimate is that this will be more like 50W rather than the 350W discussed above. An extra 1.5kWh/day, I can live with.