Leaderboard

Thanks. OK, the valve you’re fiddling with…..STOP! That is an automatic filling valve which allows the system to self-maintain pressure in the system to a pre set value. Not seen one before, but I have installed these before by buying the components and forging them in. Interfering with that valve is BAD. So, You should have an external filling loop, OR your system is “open pipe” and gets filled by a header tank aka F&E ( feed and expansion ) tank usually up high or in attic space. You need to look for a silver flexible hose with 2 chrome valves either end with taps on one or both. We need to know if this is a sealed and pressurised system or not. Having the automatic fill valve and a pressure gauge does not mean that you have a pressurised system. The plumber is a cock if he didn’t fully explain all this to you. 😑🙄

I usually buy a cheap internal door the size of the doors your fitting Attach a couple of kitchen cupboard handles and drop it in the casing while you are making them up and the same whilst fitting It will help keep everything square

Basically down to the time it takes to heat a cylinder up. Gas boilers are usually sized for the water heating needs. Heat Pumps are usually sized for the space heating needs, with a couple of kW added on for the water heating. Thing about water heating is that usual households want to bathe at similar times i.e. mornings or evenings. With a combi boiler, which is often fitted these days, there is a limit to the flow though the system. This flow rate is the product of the temperature rise required, heat capacity of water and the flow rate, divided by the power of the heater. Why combi boiler are often 40+kW in a large house. Heat pumps are very really larger than 12 kW, so just under a third of the size. This means they take (roughly) 3 times longer to heat the same amount of water up. To get around this, large cylinders are fitted. 500+litres. This is alright, unless you are only drawing off say 70 litres. Trouble then is, you get the thermal losses of a 500 litre cylinder instead of a 100 litre one. It is all a numbers game.

B and Q has little relation to a domestic situation. On a building that size, if fairly modern, there will be a very big steel grillage near the middle. This is used over a certain size of floor (2,000m2 as a vague memory.) elsewhere there are also multiple crack induce joists, which may have a flexible filler. At the big joint there is a complete break in the floor slab. Elsewhere the crack control mesh runs through the joints. Don't concern yourself with that, except to note that it is 'a thing' that is taken seriously. They are not expansion joints, but contraction joints as all concrete shrinks, and doesn't expand again unless it gets very hot. All concrete shrinks , as yours has done. I don't know the science of your screed, but presumably the heat is forcing water out of the chemical structure that has been formed when the screed was hardening. Water is taken in chemically as a part of the new material, and not all of it has to dry. I'm just surprised this happens at your temperature. The manufacturer should tell you why this has happened and if it will now be stable or expand again when cooling and perhaps taking water back into the chemical structure. The drawing is excellent, thanks. The yellow line could have been forecast, and there should have been a contraction joint near to that point, to control the crack to a nice straight line. The red crack will not stop at mid slab, and the question will be whether it carries on until it meets yellow, dives off at an angle to a door opening, or dissipates in multiple tiny cracks. None are likely to be long term problems once they stabilise. But I wouldn't be sure that have yet. Notting nasty is going to happen, but there is a risk of tiles cracking if the floor shrinks or relaxes back to where it was.

Solar PV is definitely worth it. Over a year the PV generates more than it takes to heat the house, but of course not when you need it. But we self use almost all we generate and it makes a big reduction in the electricity bill. Many of us find for much of the summer. you get much of your hot water for free from surplus PV.

ASHP. Fossil fuels aren't sold by nice people.

What ever route you go down, with a low energy house, realise things don't work the same with heating as a 'normal' house. You can operate the whole ground floor as a single zone, without lots of thermostats. I have gas boiler capable of weather compensation, but it just doesn't cope with slow house temperature change and slow change in temperature of the 100mm thick slab. I now just batch charge overnight for around 6 hours. If I wanted to do it quicker you would just increase the temperature. If you have underfloor heating in a thick slab, you can charge it up over a period of hours, then switch it off for 16 to 18 hours and your house will stay roughly the same temperature. So if you have an ASHP, you could do the house heating overnight on cheaper electric. The CoP will not be as good (due lower overnight temperature), but you are paying lots less for the electric. So you are paying gas prices and need less than a third of it compared to gas boiler. Or do as some use a Willis heater, for £60 each, always has a CoP of 1, use on cheap rate electric, same cost as gas, use an immersion or heat pump/cylinder combination for DHW.

Our current plans for the new build have factored in ASHP (at the recommendation of the architect) with UFH throughout (no radiators even on 1st floor). We are aiming for a PassivHaus type building with good thermal efficiency and airtightness with an MVHR system, and ASHP is something that seems to fit the bill as it's a new build and not a retrofit. However, I want to see whether the sums for an ASHP are really justifiable given the rapid increase in cost of electricity. Please bear with me as I work through my train of thought: General usage in our 1930s house (should be lower in the new house hopefully) 6000kWH of Electricity @ 28p/kWH = 1,680 30000kWH of Gas @ 7p/kWH = 2,100 Total cost = 3780 or 315 per month (ouch!) New house - keeping the same numbers for ease 6000kWH of Electricity @ 28p/kWH = 1,680 To get 30,000 kWH of heat output from an ASHP with a COP of say 2 (average across the year) = 15,000 kWH of electricity @ 28p/kWH = 4200 Total cost = 5880 or 490 per month (double ouch!) This is disregarding the capital outlay for an ASHP, which is going to be more even taking into account the BUS grant of 5k. Gas boiler = 2.5k (example) ASHP = 10-12k minus the 5k = 5k to 7.5k net I've not factored in all the gubbins like water storage as they'll be common in both scenarios. Does it make sense then to consider an ASHP? Realise both gas and electric prices are up, but the differential between them remains at 4:1 and I can't see gas going away anytime soon. A family member who works in the sector tells me about the introduction of Hydrogen into the gas mix and trials already being run in Scotland, which means there is a long term plan to continue using gas.

Yup. I’d go with that. The guy is a cock for not having the Wedi drop to the floor. Terrible detail there. 610 is good stuff too.

Many thanks all. We made a slight rearrangement that I'm hoping will make it a bit easier to take one of the other routes and avoid the roots/long stretch under the raft. Asked the builder for help achieving it, so see how it goes from here. 🤞

That grey stuff underneath everything, is that what they call "floor"?

You asked for it…..now I finished the build I am Into classic car restoration (learning to spray currently)

Just want to echo what others have said. Never seen a pressure regulator/reducer used as a filler. Usually a flex hose with valves each end as others have said. Even if that regulator was allowed I'm not sure why there would be any need to apply tools to it to fill the system as it should do that automatically. Edit: I'm wondering if its some sort of combined regulator and isolation valve? eg when the isolation valve is opened it introduces reduced pressure water into the system. When the isolation valve is shut no water can get in. eg its NOT an automatic filler. That might make some sense as it eliminates the possibility of over pressurising the system.

Looks worse because someone has attacked it with a grinder. Don’t worry about it and as above, decoupling mat will protect the tiles. all screeds shrink, just slowly and there are thousands of tiny cracks a bit like crazy paving, you have just concentrated them into one spot.

our tank is ancient - it looks like a primatic cylinder (online search). I can have a better look this evening when I get home

Right. Well, as above, he is a gigantic penis. It states in black and white NOT to do that. Get him to come back in person and recommission the system. The single tank ( in the attic ) could mean that your hot water tank is a bloody old ‘primatic’ cylinder which fills the heating system via a one way diaphragm inside the cylinder. We cannot rule that out. What is the highest pressure you’ve seen on the gauge?

Just make sure your tiler is going to use a good quality decoupling mat under the tiles. Schluter's ''Ditra 25'' is very good and that's what I specified on my own self-build as well as on any of our commercial projects. https://www.schluter.co.uk/media/schlueter_db_6_1_ditra_uk.pdf

Could you expand on that? Is is related to the size of the water tank we get in the property or other issues? Planning to go 3 phase as I'll be moving to an EV when my current lease runs out, and the PV system will give me 'free charging' somewhat. Not that convinced by battery tech as the man maths doesn't seem to justify it just yet.

Sure, all top hung and fixed to a concrete lintel, compression seals all round .

What a damn good idea. Whoever sorted that one out: thanks very much

Are you sure this isn't an option? Maybe consult the warranty provider and discuss. I feel your pain however. 😞 That's nice to hear. Might you have any geeky close up pics of the seals + mechanisms that differentiate the good from the bad?

I have worked on many Grant Vortex boilers and I have NEVER seen that valve used like that. There should be a normal fill loop with a valve each end to fill the system with water until it reaches the correct pressure, then you turn the water off. I SERIOUSLY think you need a different plumber, I think what the existing one is telling you to do is wrong and possibly dangerous.

I don't specifically recall. It may have been to do with wanting to let people post about their general tax situation without it being visible to casual visitors.

6 people, domestic hot water is going to be your biggest challenge, whatever type of system you choose. Consider 3 phase power, if nothing else you can easily fit more than 4 kW/16 Amp PV system.

I partly agree - while you're right, corporations and government need to be at the forefront, there's no reason individuals can't also decarbonise when at these decision moments. Induction is better than gas anyway for almost everything. It can certainly be financially beneficial to move to full electric household if you also get PV, battery storage and an EV. An ASHP fits nicely into that plan. However, if only considering heating systems and nothing else, kWh for kWh, mains gas wins on price. But you'll never be able to make your own gas.

Lidl have these in: You get 3 boards the size I'm holding, in a pack along with clips for I think a fiver. Picture on the packet shows 3 together.

The user manual for the Dream r32 inverter heat pump is attached. Happy reading everyone ESDAW-8KH-1DC.pdf EDIT: It would appear that the controller is fixed to the unit, and just has a single flow temperature setting, no mention of a DHW call or a CH call for heat in the manual. It also appears that the flow temperature can be set only as high as 40 degrees C (parameter P3). Both these things make it pretty useless for installing in a typical british home where we would expect to be able to get the flow temp up for a DHW coil, and to have a control panel mounted somewhere on the wall.

We have similar size home of 275sqm but large volume at 750m3. The ASHP used 1900kWh for heating and 1800kWh for DHW during 2021. I would recommend some PV and a PV diverter.

Whatever fuel you use you only buy insulation once and lasts (nearly) forever. I fitted my own ASHP (but have no access to gas anyway,) good insulation, solar PV and careful detailing and your energy bill will be minimal. If you design in UFH etc then the “boiler “ whatever it is can be changed out in the future. (Fusion reactor? 🤷‍♂️)

If you design/engineer to PassivHaus levels your space heating requirement will be ≤ 15kWh/m2. yr Your space heating requirement should therefore be 280 x 15 = 4200kWh per year. This would require 4667 kWh of Gas, assuming 90% efficiency, or 1200kWh of electricity, assuming a SCOP of 3.5 In my approx PH level home, I find that my HW energy requirement is roughly twice my space heating requirement, for a family of 5. Gas can be installed in new builds until 2025 and you'll have no issue getting sign-off, but the system design has to be for a low flow temp.

Fair to say that I've used very rough and deliberately pessimistic numbers to make the comparison. Reading a few threads online does make it seem that the certified installers are jacking up prices to take into account the 5k grant, so the higher prices aren't all that unreasonable though I'll certainly be doing a lot of shopping around to get lower quotes. Given that we'll also end up adding Solar PV and if we can get the COP to be closer to 3, I can see that it makes more sense to go down this route and I guess safeguards somewhat from the eventual carbon/green taxes coming our way in the future.

Mains gas is cheaper and will be for the foreseeable future. But in a passive house, the heating value will be so low it's not worth worrying about. Add solar and a desire to minimise fossil fuel usage and ASHP is looks better. However - if it is a choice between a gas boiler but we can afford more insulation OR a ASHP, then choose the gas + insulation. Design the system for low flow temperatures (which you should be doing anyway to get maximum efficiency out the condensing boiler) as this will mean a simple switch to ASHP in the future. For people without access to mains gas, in my opinion ASHP is already the better choice. Oil and LPG is up and up and very volatile and can't be supplemented with solar PV.

Thanks for the detailed reply. I certainly haven't ruled ASHP out and its useful to read that it does still make sense. One other thing that the architect mentioned when we were in the design stage is that given our build doesn't start until after June this year, new Building Regs kick in. This would make it quite difficult to get approval for a Gas boiler anyway. We are also looking at adding Solar PV in, which means that we could potentially get a few hours (in the summer at least) of 'free usage'.

Overall size of new house is 280 sq m. 6 occupants - 4 adults, and 2 kids under 5.

You don't say what size house but our 150 square metre nearly passive house uses 1400kWh heating the house each year and 1000kWh heating the hot water. We are in the Highlands so probably a colder climate than you so expect your figures to be lower.

You should achieve a COP of just over 3 between heating and hot water on an ASHP, 2 is a very pessimistic estimate. If you use 30,000kWh of heat in your 1930s house you are probably looking at 20-25k in your new house. You might well use ore energy for hot water than heating. So call it 24000kWh with a COP of 3, That is £2250 of electricity versus around £1850 of gas. I am assuming 95% boiler efficiency and 7.37p/kWh. That is a £400 difference, but you will save the gas standing charge of £100 a year, so £300. Get your COP up over 3 and the difference disappears. If you can use cheaper overnight electricity or PV to run the ASHP sometimes then it could well be the same price or cheaper than gas. I don't know who is quoting for your heating but an ASHP should absolutely not cost £8-10k more than a boiler. Maybe £3-4k more installed. Offsetting this is you won't need to install gas to the property which could save a couple of thousand. Net net I don't think there is much difference if you are starting from scratch with a well insulated house. for an older house that already has gas installed it likely remains the better option. As @SteamyTeamentioned if they start to charge for carbon the gap between gas and electricity will get smaller still.

How much is the daily had meter rental? Electrical ones seem to be around 50p/day now. If the government takes the green levies and puts them on gas, that will save 20% on electricty and add about 6% to gas.

Widespread use of hydrogen for heating looks very unlikely

If you plan to build to PassivHaus levels of insulation and air tightness then it's a waste of your time using your current property's space heating figures. You need calculated data, based on real U Values and ACH (air changes per hour). Even with Gas prices going up faster than electricity, and the good reasons that electricity will stabilise and hopefully reduce before Gas does, it's still unlikely that an ASHP will achieve parity with Gas on day-to-day running costs, nor on capital costs now that RHI has been replaced by BUS and grants will be lower in most cases. But, that doesn't mean you shouldn't consider an ASHP, or maybe direct electric if you over-achieve on your PassivHaus aspiration, avoiding the capital costs of the boiller/ASHP installation. Firstly, forget Hydrogen. There is not currently a path to 100% grid/network Hydrogen for UK housing. The Max 20% blend of hydrogen into natural gas, currently being trialled is a red-herring. It's been discussed at length on this site, have a search and read those threads if you wish to know more. Gas boilers in private residence have a finite life. From 2025 they will not be able to be installed on new properties (legislation is not in place yet, but that is the government target with the future homes standard), and replacement fossil fuel boilers will be banned by 2035 (possibly sooner for some housing types). Building regs new for this year now require a low flow temp heating system. You can still specify gas, but it has to be designed around a low flow temp to ensure replacement with non-fossil fuel boilers in the future can be done without too much rework. Your 2.5K gas pricing suggests you are comparing to a combi gas boiler. The Regs are pushing new properties towards a system boiler with a a hot water tank so the Gas v. ASHP installation will now be very similar in all but the boiler itself. If HWC, buffer tank, valves and pumps are all equal, the price difference will just be the difference between a Gas system boiler and the ASHP itself. The 5K BUS grant should get close to closing that gap. If you do go with Gas, to future proof the house you should consider a UVC, maybe a buffer tank for UFH and a route to these from where an ASHP would be located for the pipework.

A lot will depend on the look you want to achieve. I loathe uPVC and wanted timber, my husband didn't want the maintenance of timber so we went with aluclad (best of both worlds). We looked at aluminium as a cost comparison, and it seemed that good efficient alu products are pretty compatible to aluclad timber price wise and I didn't like the look of aluminium internally. I looked at loads and loads of options and chose Nordan. A big factor for us was the cost, Nordan came out ahead of competitors there. I really liked the profile externally - it wasn't just plain and boxy. They do not have in house fitters so you'll need to do the leg work there, although they have a list of recommended installers (but do your own due diligence on them). We wanted to celebrate the timber internally and Nordan offer a clear lacquered timber (other stains etc available too), the timber is engineered to make it stronger and take out the knots so looks a bit like a solid wooden counter top, with lots of small rectangular pieces finger jointed together. If natural/stained timber look appeals to you, don't go with Rational as it's not done well. We went for a classic profile inside, which again stopped it from looking square and boxy & gave more of a traditional feel. We had double glazing but they do triple glazing and loads of different opening options and products with varying u-values I think they offer PH products too but don't quote me on that. Their website lacked information as did their brochure and we struggled a bit with logistics, they weren't faultless by any means. We have a showroom local to us which was really helpful & well worth a visit. We're really, happy now everything is fitted, it looks great, and it was good value compared to many other companies. Also, when there were issues, they were pretty good at sorting things out. I will also mention Norrsken who came a close second to Nordan but were more expensive, they do however offer an in-house installation. Hope that is helpful to you in making a decision!

I let SWMBO lay the flints out in patterns she chose. Threw the mortar into the recess off the end of the trowel, pushed them in, more mortar. Ratchet strapped a bit of scaffold against it and walked away. Came back the next day, another small mix to point etc. Rubbed it in with a gloved hand, brush etc. Bottom panel is going ok I think. Top mortar spacing is too wide but i) hopefully the eye will be drawn away by the coach lantern and intercom, ii) I can't be arsed with it any more.

That is immaculate!

And I bet his wife is loading out the floor beams 2 at a time!

Welcome. Have a look at the Funding Self Builds section of the site. Lots of people have lived in really quite difficult surroundings while completing their build. Caravans can be made 'nice', but at the cost of diverting effort from the build. It's an added stress that should not be underestimated. The process wears everyone down. Except @nodwho has too much energy and determination.

If you can go around the outside then do it! The extra bit of cost will be outweighed by peace of mind. couple of years ago saw a new build where drains were run under properties and one needed the whole ground floor digging out after settlement destroyed a pipe run. Then again the mass builder also didn’t dig footings - they heaped type1 on the inside and soil outside to form trenches 🙈

Im in the process of making a complaint and requesting he never darkens my (yet to exist) door again but await how successful I’ll be. Positively he’s not now back until roof at least and we’re just tearing out the cavity tray and XPS so the beads can go all the way to the bottom of the cavity.

My brother had an orangery added to his house. Original house built on deep plies. Orangery on a raft. Clay soil. After a fairly short time the orangery doors seized. It has now been demolished as it risked causing structural damage to the house.