ProDave

Early on in our build in summer 2016, the outside of the house was rendered using the Baumit.com render system consisting of a lime based base coat mixed from powder called MC55W, a fibreglass mesh was rolled into this while wet. Then it was painted with DG27 primer and a top coat of Silikon Top applied. This was all applied to Pavatex wood fibre board cladding a timber framed house. There was a BBA certificate for this render system that I have attached. The result was crisp and sharp looking. But that did not last long. First winter, 2017 the first problem appeared, the top coat started blistering along the bottom of the east facing garage wall. It occurred while we were away over a cold spell, so thought perhaps it was a build up of snow along the bottom of the garage wall? (we came back to very thick solid ice all over the driveway). The plasterer came and re worked that using materials we still had left over. But since then the problem has spread. Next year it showed itself as just a couple of blisters on the East wall. But it has continued to get worse. After another year or 2 the blisters started to spread and the early ones started to crack. It is now in places on 3 walls, (none yet on the south facing wall) and along the top of one door and one window it has come away from the drip bead and is cracking all along the top. I have been trying via the plasterer for some time to get a resolution. He kept saying he was trying to contact the rep for the area to get him to come and look but with no luck, and of course all last year Covid has been the excuse. So while I don't have much else to do just now I have picked this up and tried contacting the supplier myself. First thing I find is the company that supplied it merged with another so are now trading under a different name, and the rep we were trying to contact no longer works for them. I have been given the details of a person that will deal with this so I have sent an email to start the discussion and hope we can find a resolution. In the mean time here are some photographs. This is the East wall, the garage wall. All allong the bottom it has delaminated from the drip bead, and all the way up there are blisters though they can be hard to see. Note the corner joint by the door is delaminating. Above the garage door on the east wall, delaminatinf all around the door and some hard to see blisters further up. Some of the east wall blisters close up, one has started to crack. Corner of garage east wall and north wall delaminating at the corner West facing wall, hard to see blisters in the wall and corner delaminating West wall above kitchen window delaminating and cracking And saving the worst until last, north wall corner of garage. This winter a chunk of the base coat fell off. I don't believe the root of the problem is related to the base coat, rather this is what happens with the top coat failed allowing water to soak into the base coat then the action of frost has cracked it. While I await a response from the supplier, I wonder if anyone has seen anything similar with a thin coat render system, if so what was the reason for the problem and what was the resolution? bba-certificate-for-nbt-timber-frame-rendered.pdf

What do you think will cause your wood flooring to warp / peel / rot or otherwise fail? Are you concerned about wet areas (kitchen) or the UFH? We have engineered Oak wood flooring throughout the living room, part of the entrance hall, and the kitchen / diner. When choosing it, we specifically said to the supplier recommend a product that will work with UFH and they came up with the large format planks we have, 180mm wide and up to 2.1M long. In the kitchen we just have a mat in front of the sink and hob area to protect the floor from spillages. So far (2 years in) it is all very stable with no issues.

Sory missed this first time around. Look in the instruction manual for the inverter. there should be a G98 conformance certificate from the manufacturer and you want the details from that, or just send a copy of that certificate. If you don't have one, contact the supplier and ask for the manufacturers G98 compliance certificate. Our DNO got a bit shirty because my inverter had "4000" in it's part number and they did not believe it was limited to 3.68kW until I forwarded the manufacturers declaration to say it was.

It sounds like you need to move house to the east coast somewhere?

Nothing but a tiny amount of condensation on the very edges of the glass on my Rationel windows. And I am sure it's a good deal colder here. I suggest a ventilation problem. Has you MVHR been ballanced? Are you using boost while showering?

How thick is this panel? UFH will of course elevate the floor temperature, so any heat loss through the floor will be greater than the same room heated with radiators where the floor would remain cool. so it is important to insulate a floor well for UFH. Yes it will "work" but how much of the heat that you put in will end up in the room, and how much will heat the under floor space and the outside? One member on here worked out that even with 300mm of floor insulation, he still lost 8% of the heat put in down into the ground. I personally think the company is being reckless to make the claims they are, I would take up all the floor boards, string a netting (netlon) across the bottom of the joists and lay rockwool type insulation between all the joists, put the boards back and put your UFH system on top.

Okay there is a practical limit of about 10kW electrical power for a single phase supply, so to get the mosters, or a bank of them, you would need a 3 phase supply. If you need that much heat your money would be better spent reducing the amount of heat the house needs.

My point was, a lot of old poorly insulated and leaky houses have a heat demand that is higher than any ASHP made and yet installers still specify one with a large degree of hope. That is where you see failed installations that cannot get a house warm enough.

Last time I looked you cannot do more than 100M in one run with Cat6 so would need something half way. What about 4G mobile? If you get a good signal from three they do a very good cheap unlimited data sim.

Not true. My 5kW ASHP has been heating my house nicely here in the Highlands where we are now into the 7th consecutive week of average temperature below 0 and -16 one night (a new record in the time we have been here) Last night was -7.5 Where they struggle is in poorly insulated houses and where they have been specified too small as the designer failed to correctly calculate or measure the actual heat load needed.

@joe90 I believe your stove is ducted air in? What diameter is that pipe? Mine has an 80mm diameter inlet pipe and the duct down through the wall to the under floor void is the standard plastic extract fan ducting the flat rectangular one.

I can't see a buffer tank will change anything. That won't make it produce more heat. A buffer tank even outs the heat load for when it is running at low power when not much heat is needed. I suspect smoke and mirrors here, by the time they can get around to installing this buffer it will have warmed up, they will claim success and sweep it under the carpet, so I would only accept them trying that with a written undertaking that if it still fails to perform for the entire next winter they will look at it again. Can I ask what heating you had before and do you still have any old winter heating bills?

Isn't the fact that the extension was built long enough ago that no enforcement action could be taken by planning or building control now?

Which for my burn with a 1M drop, each 1kg/s water falling will give me 10W of electricity. It's easy to see with my modest burn and only diverting a portion of the flow would not amount to much power.

I would do the whole lot with 15mm pink fireline. If it is only a timber frame between the house and garage, that will need 2 layers of fireline with staggered joints and taped and filled or skimmed.

No insulation under the floor, I very much doubt an UFH overlay board system has "enough" insulation.

I would want to know WHY they are sloping? Built badly or subsidence? We tried once to buy a small timber bungalow with subsidence like that in one wing. Our short term plan would have been to level the floor (it would not have fixed the wonky walls or ceiling) and let it for a while with the long term plan knock it down and rebuild.

For a stove that only needs a 12mm hearth, I would insulate under it and put exactly the same floor finish as the rest of the room and just put the glass hearth on top. It is okay to draw combustion air from a ventilated under floor space it does not need any form of fan. Assuming you are not getting a glass hearth with a hole in it for the air duct, it is best to build a length of duct into the wall behind the stove to draw it's air from below.

What insulation is under the floor?

Tenants want something that "works" but importantly from your point of view that the tenants can's mess with and break. A lot of ASHP's have fiendishly complicated control units supplied with them. I can imagine if the tenants started trying to understand one of those, they could rapidly get in a mess, change some settings they should not and do not understand and stop it working. So i would suggest you do as I do, link the ASHP to a conventional central heating programmer to set the HW and heating on and off times, and put the ASHP's own controller away somehwere the tenant can't get to, like a locked plant room.

Then call them round NOW while it is cold and task them with making it work. you really don't care how they do that as long as it ends up working in very cold weather.

Hi and welcome to the forum. I am sad to say my gut feeling is whoever sized your system got the heat loss calculations wrong and the fact is, 5kW is not enough to heat your property when it is really cold. A 2001 build could be really good, or ot could be pretty mediocre. A lot of it will be how well it was detailed. Did you buy it as a design and install package? Have you gone back to the supplier to tell them it is not performing adequately?

Here is the data sheet for your thermostat https://cdn.wundatrade.co.uk/wp-content/uploads/2017/08/E02-generic-E91-touch-screen-Stat-27-4-2018.pdf See page 3. Parameter 4diF Switching differential, adjustable from 0.5C to 10C

I was about to say that. Don't even attempt it DIY if undermount, it has to look right.

So a posh electronic one? Why does it have so much hysterisis? Is that something you can adjust? Do you have a model number?