Jeremy Harris

You wrote this (my highlight): Tapping in to an existing water communication pipe is not allowed. I know, I've had chapter and verse on this, been through all the water regs and ended up having to drill a borehole for water as I wasn't legally allowed to connect to the 1 1/2" water pipe that literally runs 6 m away from our front door. You are only allowed to connect to a pipe that is designated as a water main. A pipe feeding a single property from a water main is a communication pipe, by definition.

+1 ^^ Designing it as a mini-basement seems a good way to tackle this. Shouldn't be that complex a design, as the low perimeter walls of the "basement" section aren't seeing much inward force from the surrounding soil.

Same here, we're also on clay. We had to (as does everyone, AFAIK) comply with the SuDS regulations for surface and roof water drainage. The solution was to bury 20 drainage crates in a hole under the drive. By good fortune there was a small patch of porous soil in one corner of the hole, through which rainwater percolates away and ends up in the adjacent stream. We weren't permitted to drain the water into the stream, but apparently hiding the drainage path so that it isn't on the surface is allowable. The crates we used were the 196 litre heavy duty Aquacells, which I managed to buy on eBay for a fraction of the normal price. They are a recognised compliant solution, so just a matter of working out the volume you need from the chart in Part H. About a day's work to dig the hole, run all the pipes, install the crates (wrapped in terram) and backfill. Seems to work OK.

Not sure that it's wise to recommend breaching regs (and possibly the law). The regs now prohibit illicitly connecting a second dwelling to the pipes running to/from an existing dwelling, there would be fraud implications, especially if the existing dwelling isn't on a metered water supply, plus building control would almost certainly flag it during the drain inspection and test. Probably not that great an idea to promote potentially unlawful activity on this forum, either. "Trade" prices aren't always the best, as many trade suppliers offer credit, as many trades people rely on supplier credit to reduce their up-front risk (having 30 days to pay suppliers gives them time to get paid for the work). I found that offering cash with order pretty much always got better pricing, and many online suppliers easily beat the very best prices from builder's merchants. As an example, I set up a cash account with my local independent builder's merchant, which was about 5% to 15% cheaper than the prices I would have got from a trade account. However, when I wanted a load of reconstituted stone, plus the pavers for the drive, I got a very much better price from an online supplier. My local BM offered to try and price match (I built up a good relationship with them), but they told me that they couldn't even buy in the stuff at the price I was getting from the online supplier.

I can understand them wanting to insist on the unit being correctly installed for warranty purposes, but it's no harder than installing a hot water tank with an immersion, so it's pretty hard to see how the installation could be messed up. The older Sunamp PV was slightly more complex to install, as it needed a drain and tundish for the pressure relief valve, but Sunamp were fine with "training" me via a half hour phone call and some email exchanges. Not sure how long their installer training sessions are, but I'd be surprised if they took more than 1 day. If the installer is a one-man-band and doesn't have to travel from miles away, then £600 for connecting four pipes on the Sunamp to two pipes in the house, plus connecting up four cables, seems seriously OTT. Might be worth sending a PM to @Nickfromwales to discretely ask his opinion (off-air). Technically I'm still a Sunamp installer, I think, and have installed two of them now. If I lived closer I'd pop over and double check that your plumber/electrician had made the right connections, turn the thing on and check it was OK for a cup of tea and bit of cake!

Best not get it on your skin, and definitely try and keep it away from streams and ponds, but other than that it's not too bad. It's been used for many years as a fungicide on plants. I believe it's also been used as a fertiliser, too, but I'm not quite sure how that works, just from the chemistry. Probably not a good idea to spray it near pets or other animals, but it seems fine once it's dried on the roof.

Yes, looks like more finger trouble... Not sure how the "2" ended up in front of the "5", I'll edit it.

This is a list of the work that needs to be done to install a Sunamp, assuming that there is switched power and water pipes available at the installation position: Unload Sunamp from vehicle and move to the installation location. Unpack it, check for damage and prepare the pipe connections (parallel up the two sets of 22mm heat exchanger pipes) - perhaps 1 hour's work at the most Electrical works - fix controller box to wall adjacent to Sunamp, connect the Sunamp power and sensor cables, and the incoming power cables - perhaps 30 minutes work Plumbing works - connect Sunamp inlet pipe to cold supply pipe and connect Sunamp hot water outlet pipe to hot water pipe. Perhaps install a thermostatic mixer valve. - perhaps 1 hours work at most Perform electrical safety testing and water leak testing, turn power on to the unit and check that the controller initialises and that the heating element is powered. Wait for ~30 minutes to allow Sunamp to partially charge and test to ensure warm water is being supplied - perhaps 1 hours work The total time taken to install and commission a Sunamp should be around 3 1/2, perhaps 4, hours, and although two people are needed to lift and manhandle the unit into place, everything else is a single person job. The cost of that depends very much on how far the installer has to travel. £600 sounds a bit steep to me, I'd have thought maybe half that might be more reasonable, but if the installers (assuming it's two of them) have to drive for half a day to get to you and back, then £600 might not be too far off the mark. Is there any reason why your plumber and electrician can't plumb and wire the the thing up? It's no harder to install than a normal hot water cylinder with an immersion heater, if anything it's a bit easier to work on, as all the pipe connections are easy to get at in the top of the unit.

60m² is fine for a single ring final, so my guess is OK (there's no limit to the number of outlets on a single ring final circuit, just an area limit). You will need to add the studio power and lighting circuits to the earlier load estimate though. You could probably get away with a radial power outlet circuit for the studio at 16 A, plus a 6 A lighting circuit, so that adds another 13 A + 3.96 A = 16.96 A to the total, bringing it up from 67 A to nearly 84 A, so just too high for your 80 A supply, even without a water heater (but bear in mind that I've guessed the load for the ASHP and cooker). I think you need to sit down with your electrician (as he'll be the one signing this off) and discuss all the loads, both in the house and in the studio, and work out a wiring configuration that enables you to stay within the maximum demand limit. Some electricians are a bit more forgiving than others when it comes to applying diversity to loads to check that the maximum load is within limits, although strictly speaking they should work to the letter of the regs. The flip side is that sometimes a strict interpretation might be applied, too. You can probably help by ensuring that you know things like the ASHP maximum input power and the cooker maximum input power. Opting for a separate oven and hob, or perhaps two ovens and hob, can increase the load a lot. For example, we have two built in ovens plus an induction hob and the maximum peak load on the cooker circuit is 63 A, not the 40 A I assumed earlier.

The maximum rating for any water heater (if the assumptions I've made above as to the loads is accurate - it may not be!) would be 13 A, just about enough for an immersion heater, but not enough for an instant water heater. If you can get the supply uprated to 100 A, then you have about 33 A available, so could then install a 7.5 kW instant water heater. This all depends on the actual loads you have though - if you have two ring final circuits and two lighting circuits the load will increase a fair bit. Splitting a priority load switch across two locations is possible, but not ideal, really, as it would make things a bit messy. A lot depends on the physical arrangement of the studio relative to the main house. Also, if the studio has it's own power and lighting circuits on a separate consumer unit, fed from the same incoming main fuse, then these have to be added to the load calculation above, so will impact on the total load and may even take you close to, or over, the allowable limit with an 80 A fuse, without any water heater. Do you know what the input power rating of the ASHP and the cooker is? I've just guessed numbers for those, so may have over-estimated. Also, do you know the floor area of the house? If over 100m² then two ring final circuits may be needed, in addition to any circuits in the studio.

Harvard 2B from the (brief) look at it. Father in law flew them in Kenya in the 1950's.

OK, so I'm guessing here that your electrician is planning ahead and has worked out that the sum of the loads, allowing for diversity, exceeds the 80 A fuse. I've listed what I'm guessing you may have in the consumer unit (once it's fitted): 1 off ring final circuit at 32 A, allowing for diversity = 10 A + (50% of (32 A - 10 A))) = 21 A (these are your 13 A outlets, I'm assuming there will be only one circuit as the house is a modest size - need the number of outlets to do a proper calculation, really. If your floor area exceeds 100m² then you need a second ring final circuit) 1 off lighting circuit at 6 A, allowing for diversity = 6 A x 66% = 3.96 A (same assumption as above, just one circuit assumed) 1 off Sunamp circuit at 16 A, allowing for diversity and assuming the heating element is rated at 3 kW = 13 A 1 off ASHP circuit at 16 A (need to check this, and need power rating of ASHP) = probably around 10 A (could be a bit lower) 1 off electric water heater at 60 A (48 A appliance load, no diversity allowable) = 48 A 1 off cooker circuit at 40 A (might be 32 A, or could possibly be 50 A, need the maximum power on the appliance(s) label(s)), allowing for diversity = 10 A + (30% x 30 A) = 19 A (add 5 A to this if there is a socket on the cooker outlet switch plate). The sum of all the above comes to 21 A + 3.96 A + 13 A + 10 A + 48 A + 19 A = 114.96 A This is way over the 80 A supply limit, and also way over a 100 A supply limit too. Fitting a priority load switch so that the cooker and electric water heater share the same circuit (needs care over circuit protection devices to do this) would allow you to stay under the 80 A limit, but would mean that the cooker and the electric water heater couldn't be used at the same time. You can choose which you wish to take priority over the other. The alternative is to get rid of the water heater. There isn't enough spare capacity (based on the rough and ready estimates above) to allow any reasonable size of instant water heater to work OK really. Without the water heater the maximum demand comes down to about 67 A, well within the limit of the supply.

80 A might still be too low to allow the water heater to be connected without a priority switch, best to check. If you can take a photo of the consumer unit then that should show all the circuits well enough to do the sums.

It's really the circuits coming from the consumer unit that are needed. You should have a set of circuit breakers that are labelled, one for each circuit. Typically these would be something like two ring final circuits (maybe upstairs and downstairs) with 32 A MCBs, two lighting circuits, again upstairs and downstairs, with 6 A MCBs, a circuit for the ASHP (need the rating of the MCB, probably about 16 A I suspect), the cooker circuit (typically about 40 A), the water heater circuit (probably about 50 A), The Sunamp circuit (probably 16 A). If you can check what you have in the consumer unit then it's a pretty quick job to do the diversity sums and see what the maximum load is.

If you can give that list of circuits that are being run from this supply then it's five minutes work to tell you the answer. It may be that your electrician has misread the main fuse as being 60 A rather than 80 A, but it's easy to calculate whether you can have the instant water heater connected without a priority switch.

Unfortunately they all say 100 A on the fuse carrier, it's the rating of the actual fuse fitted inside that matters. This can't be accessed without breaking the seal, though. That does look as if it's fairly new and has an 80 A fuse, rather than a 60 A one, though.

If you can list the circuits you have coming from your consumer unit, then I can have a go at working out what you might best be able to do to be able to retain the 11 kW inline heater with the other loads from that supply. At a guess I'd say you probably have a couple of ring finals, a couple of lighting circuits, a cooker circuit, the water heater circuit and maybe an immersion heater circuit (not sure how the Sunamp is being heated). You may have other circuits as well, for example we have separate circuits for the garage, water treatment plant, borehole water pump, ASHP etc. All have to be included when working out the maximum allowable load, and it should then be possible to pick the second highest load and use that, together with a priority switch, to keep the maximum load below the 60 A limit.

BTW, that priority shower board doesn't have to be used for electric showers, you can use it to prevent the water heater running whilst the cooker is on if needed. This would then bring your installation back within the maximum allowable demand so it could be signed off as safe. I know someone who uses one to allow him to have two electric car charge points, the priority switch stops both being use at the same time, which could overload his incoming supply.

It only works on the salary multiplier, usually. I've not encountered a lender that will increase the amount borrowed over and above that multiplier. For a salary of £30k the maximum a lender is likely to advance will be £135k. They will check that you don't have higher than normal outgoings, just to be confident that you're going to be able to meet the repayments, but they won't lend you more if your outgoings are unusually low, as a general rule.

Is the shower not electric as well? As you'd mentioned the shower and cooker being on at the same time as the water heater I assumed it was. The problem is that the maximum current that the supply can deliver is limited by the 60 A fuse on the incomer. An 11 kW electric water heater is going to draw about 48 A, leaving 12 A for everything else running from that supply. There's a thing called the diversity that is applied to the electrical loads which allows for not all of them being on at the same time. For example, for a cooker it's assumed that it will draw 10 A plus 30% of the maximum rated load over 10 A (if the cooker outlet has no 13 A outlet as well). For a cooker rated at 40 A (not unusual) then the cooker load would be 10 A + (30% x 30 A) = 19 A. The sum of the cooker and water heater load alone (ignoring everything else on that incoming fuse) would now be 67 A, over the 60 A rating of the fuse. The ring final and lighting circuits also need to be accounted for, and adding those as well increases the maximum allowable load even more. Your electrician cannot sign off the installation if the total load exceeds that which can be safely delivered by the incoming supply.

As pretty much every lender only lends up to a fixed multiple of income, then outgoings don't make any significant difference as far as a mortgage goes. If the limit is 4.5 times your income, then that's the limit, and I doubt that it could be increased.

It's a diversity problem, rather than an individual appliance maximum load problem. If both the water heater and shower were on (neither of which can have diversity applied) then the installation would be overloaded. The Garo unit that gets around this is this one: http://www.meteorelectrical.com/distribution-control/consumer-units-accessories-1/garo-priority-shower-board-choose-priority.html

He's right, it exceeds the maximum allowable load under the diversity rule. Best bet is to ask your DNO if you can have a 100 A supply instead of the 60 A one. Whether or not this is possible depends very much on your local grid load, as often the supply cables used for a 60 A supply are the same size as those for a 100 A supply. The DNO may ask you for a contribution towards local grid reinforcement, though, which might be costly. Still worth asking, as sometimes 60 A supplies were put in before local grid reinforcement work was undertaken, so there may be spare capacity. An alternative would be to deal with the diversity problem by fitting a unit to prevent the shower and water heater being used at the same time. Might just get you inside the limit, depending on what else you have in the house. Garo make a unit to do this, they are popular in Ireland, where 60 A supplies are fairly commonplace.

I just used standard PB, as experience with the Multipanels fitted to our old bathroom showed that they are 100% watertight, including the vertical joints. As @Onoff says, the weakest point is at the bottom of the panel, where it joins the bath/shower tray. I tanked the wall for about 200mm up from that junction and fitted the panels on 4mm plywood spacers, then removed the spacers and filled the gap at the bottom with sealant. The gap allows for any slight movement and is wide enough to be able to squirt sealant right in to ensure a good seal.

The only way spiders seem to get in to our house (or used to) was when a door was opened. As @PeterStarck says, they seem to congregate at the bottom of outside doors and run in when the door is opened. I've completely stopped this now, with a diluted peppermint oil spray. It seems spiders don't much like the smell of peppermint, so stay away from it. Since using this we've had no spiders coming in through the doors at all. The only downside is that you have to spray the door threshold every 2 to 3 weeks, as the peppermint oil slowly evaporates.