PeterW

TBH reading that it majors on the “environmental factors” and there is no indication as to how long this will last or why it’s better than DG or TG..? You can get Argon filled DG with low-E coatings at near 1.3 so their numbers are way off. I’d like to see some real data about how robust these are.

Before you do anything I would be getting the heat output for the floors and then ensure you have a decent programming and control method sorted. Have you got space on the ground floor for the buffer ..??

Give her the £1000 you save to spend on the bathroom....

Yup but they have to have a vertical column for the heating element to go into. Horizontal ones don’t work as well.

Any reason you’ve discounted something like a log gasification boiler ..??

Ok so the first and second floors doesn’t make any sense ..!! With no screed and the low heat capacity, along with the insulating capability of the carpet you are more likely to need closer than 250mm pipe spacing. These are all going to need to run for different times and at different temperatures - more than ever I would be putting a buffer into this as you are going to need to do some clever controls. Please tell me you’re not using Heatmiser stats in every room ..???

Yes - use 1” stainless self tappers.

Ok so that 1.6kW is the output at 55°C which is 20°C more than you need for UFH, so you may as well say that’s possibly double what need at standard UFH temperatures. What are the design temperatures for the system by the designer ..? I was assuming the plumber has requested the zone valves ..? Have all manifolds got a full set of actuators, blending valve and pump each ..? Are all floors timber with spreader plates or are there a mix of solid and timber floors ..? What are the final floor coverings ..??

200mm is fine - can go to 150mm if you want to. Just may end up with a shorter fascia.

Depends...! Some are oil filled but they just use cheap silicone oil. You can use that but my weapon of choice is car antifreeze - the pink one - as it’s ridiculously cheap in Home Bargains and works as an inhibitor too. Just stick the elements in, use the breather plug in the top and then buy a pack of rad plugs for the other holes.

Looking at that they appear to have pushed the extended piece in then put the connector inside the new liner. That is going to leak and is the wrong way round. Every piece should have the next one up inside it. I would get them back, get them to take out the cement around the pipe and redo it properly. When was it last swept out of interest ..?

@cl2702 have you got any better photos of the whole of the internal chimney area as I’m struggling with this - does the stove have a dogleg at the top to get through the wall ..?? I wonder if they have used a reducer and it’s not sealed properly and you’re seeing the issue now as condensation is pooling at the bottom and leaking where before it ran straight into the stove.

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I would out the buffer in now... it will not modulate down far enough, and you will have issues. Look at your heat loss for a single room, then see if the boiler can modulate to lower than the heat input requirement - very very unlikely. Without this you need a relay module - each wiring centre will call for heat and trigger the relay with the NO contacts connecting to the boiler call for heat. You could try and use the zone valve micro switch but that’s better used to run the pumps. What boiler has been specced..? Internal circulation pump ..?

Does each wiring centre and manifold have its own pump ..? I would have the pump, wiring Centre and zone valve all at the manifold, and then have the buffer tank thermostat running to the boiler for the call for heat. In this scenario, the UFH zone calls for heat, the zone valve opens and when it’s fully open the manifold pump starts. As this draws hot water from the buffer then the buffer thermostat will trigger the boiler. This keeps it all very simple with each floor managing its own part of the system. Depending on distance you may need secondary pumps to draw the heat to the manifolds, alternate to this is you blend leaving the buffer and do not have TMVs on the manifolds but that does mean some zones may suffer with lower levels of heat being supplied. Who’s designed the system ..??

@juncopartner instead of playing the person - which you are - perhaps you could use your professional guidance and quote the correct regulations instead of telling everyone what the answer isn’t ..?? From ADB, 2020 amendments, a ceiling in a 2 storey residential class 1.(c) property doesn’t require anything more than 30 minutes fire resistance and this can be achieved with 12.5mm standard plasterboard. A steel enclosed in this floor space is therefore protects from the effect of fire and requires no further protection. Correct or incorrect ..?

@joe90 what do you call “high” internal RH..? Running the same HEx as you - so no drain - and seems to sit at 58-62%

Insulated plasterboard is a pig to work with and expensive. You can do all the other stuff yourself and get back boxes in the right places etc easily with 25mm insulation. 145mm PIR will get you to Regs and you can detail it much easier if you want to do it yourself.

Assuming you are in England and this is an extension then the ceiling of the dormer is borderline being at regs for a cold roof (assuming it as a ventilated space above it) I would simplify this whole thing and use 25x50 battens at 400mm centres and infill between the battens with 25mm PIR, taping the joints and the battens over with foil tape. If you do this on all walls and ceiling you will end up with a very good airtight continuous vapour barrier, and then it’s a case of putting standard board over the top and skim. Sockets aren’t an issue with vapour barriers - if you do as above then you create a natural service void for the back boxes anyway in the insulation.

@bradders3109 Stroma deal in sustainability. Sounds like you need a decent structural engineer on the job more than anything - Your regs plans aren’t complicated from looking at your plans.

Single skin 100mm is good to 9m height ( @Gus Potter..??) from memory with pilasters so 140mm would be fine. Keep the runs below 7m without a return wall or support and you’ll be golden.

Welcome ! Any reason for the block on flat ..? Could do similar with 140mm blocks and save yourself quite a lot on blocks, mortar and labour. Will also give you a bit more space in the rooms - if all your insulation is outside then you may as well have the additional room inside.

Bin the oversite and the sand, double the thickness of the screed to 100mm and use concrete and then drop the PIR onto the MoT1 and the DPM. It has gained you 100mm min already.

Ok so crossed wires here.... When the PV is commissioned and the diverter is also installed, there is a connection to allow the ASHP to trigger the immersion to boost. You can just leave it and it will do it once a month, or you can get the plumber to remove the setting from the programme. Currently as it’s installed the relay has clicked “on” to do the cycle but the the heater engaged and the temperature hasn’t moved so it’s thrown the error after a couple of hours. Another lovely install “feature” your plumber forgot to tell you about ....

Lead isn’t that expensive - you would only need 180mm Code 3 for that so it’s 10 rolls and that would be about £340 currently. As it is very visible none of the lead alternatives are suitable as they look crap. You could get a folded plastisol type cill done but that would be about £10-15/m so twice the cost of lead. 60m of plinths is 270 bricks - think they are about £1.45 currently (not sure for a full pack may be cheaper) so that is £386 - cheaper than lead as you’ll need another course of facings anyway if you go the lead route plus someone to install it and patination oil etc