Gus Potter

Can I ask, did you buy this at auction?

Yes. 1/ Invest in a good Co monitor. 2/ Check your flue. 3/ Accept that if you have not run the stove for a few months you will get a "funny smell" as it dries out the surrounding structure. 4/ When was the last time you replaced the door seal to the stove? bet you have not! 5/ The flue vacum will change as the chimney warms up.. you are chasing the dragon here. If you check the basics then come back to us describing the problem in more detail. Why are you indulging in this? Have you not got something better to do? The flue pressure will change a lot depending on which way the wind blows! I know this as I'm an SE. The reason I'm being a bit rough with you is this. Young and new self builders may look at your posts and get worried that self building is so hard these days, it's not worth the effort. I think it is the best thing you can do, is to build your own house! I'm here to encourage young folk as they are the future! But they do need information from folk like myself to enable them to make informed decisions. Make no mistake here, many of my posts are intended to inform.. it up to you as grown ups to decide!

Ah philistine here. Why on gods earth are we designing systems that are not passive in the UK to cool houses? Why not design our doors / ground floor windows to provide purge ventilation and say put Velux windows in the roof to promote passive stack type convection with a bit of cross flow ventilation. You can achieve this even on a single story building. Again I'll come back to this. I've been designing UFH as a designer and as an SE for decades. So I kind of know what the long term costs are. And no one on BH has stepped up to this plate.. yet.. I'm alone in my view it seems. But the thing is.. I'm pretty good at maths, have installed and designed UFH when most of you were in short pants, I know the economics! and to boot I'm an SE so know how you integrate UFH structurally. So get that up you and lets see some evidence about long term maintenance costs on UFH and the introduction of complex controls.. Oh and if you can make that basic argument then have a go at cooling. If you want to make your arguement then explain how pipes in the floors work over the design life of the house first. Work up from there. Go on and give it a go! I'm willing to learn.

I've seen a lot of changes in the merchants business over the last 40 years ago. One thing that has driven this is that is it a lot harder for them to take cash and not really put it through the books. The other is that the increase in dodgy customers who don't pay their bills has also increased.

That's a bad show. Hope this gives you a few pointers, some points you will already be aware of, but this post is also intended to help others that may be in a similar position to you. You are not the first to have an extended project so take heart from that. I've recently had a Client who started a project under their own steam, but their financing arrangments changed and they needed a warranty retro actively for lending purposes. But you are specifically talking about an insurer. Is that just say for public liability, contents etc. But say, for all on BH this is for warranty (10 year) purposes, like an NHBC warranty. In your case I think the starting point is to show that what you have built so far is ok. You are going to have to do a bit of work! Gather together all the site record photos you have, invoices and so on, itemise who did each part of the work so far. Put that in a big folder, even if it looks spurious! This is your evidence base. Next step is to contact your original design team and ask if they can help. You should indicate that you are willing to pay for this service. Sound them out, even if you offer say £200 quid for a quick consultation. Be proactive with the cash! Now they may not want to get involved. Very occasionally I do this, but only if I'm going to get a fair days pay for a fair days work. But when I do I give it full pelters and you need to be willing to pay about £ 275 - £300 quid a day for my time. So if you take my rate then anticipate / compare that your design team may charge similar. Make no mistake, I'm not touting for work as your design team already have a head start. When I get involved I look at two primary things. First is what evidence do we have that what you have built is ok and how do we package that up so a broker / insurer will be interested in quoting for something that carries a higher risk. Have any site inspections been carried out by the insurer that has stepped awy from this? If you have record then this is good evidence. As an SE I'm very aware of risk, as are my insurers. It's about putting something together that insurers can quickly understand and engage in the detail that leads up to a quotation you can live with. You can almost insure anything. In your case the premium will likely increase, but if you present well you may find that more than one insurer will be interested. As a final word of encouragement. A recent Client got the run around from Protek admin, but once we elevated that to director level they were great... but we had to do a lot of leg work first for them to recognise we were not trying to take the piss out of them. I bet they don't..there will, I suspect be all sorts of agreements, maybe some NDA', side marketing and product placement deals.

Good point, design is an iterative process.

Agree with @Nickfromwales Is the floor separating two different dwellings? If you are adding load to the floor have you checked that is ok? A drawing would help a lot. You need to start with the basics and develop from there. You can maybe see it but for us it's difficult to comprehend as a complete floor design. If we can't understand it then little chance your builder will and the prices you get will reflect that.

Hello webby. Thanks for a good post and the work you have put in. I've attached a document from the RICS which is to do with spray foam insulation. This might seem a bit odd as at first glance it has got nothing to do with your post. But read the last paragraph of page 4. Then look at the diagram on page 5, then read around. For all on BH, it's also a good guide to help you understand some of the basics about roof insulation. @webbythewebster. Here is a bit of a lay persons guide to insulating an old loft. Let's say your Dad's ceiling is just plasterboard, painted but with no vapour barrier and it's got say 100mm of glass wool at the moment. I'm going to call simplistically water vapour a gas. When the gas gets cold enough the water gas turns into water drops and at that point the problem starts. Gas molecules are farther apart and move more freely than liquid molecules so they can get out the roof more easily. The paint (may have some gloss paint) acts as a bit of a vapour barrier. The loft space may have some ventilation but not that much. When the weather is cold some moist air will penetrate the ceiling and now and again, depending on the temperature in the void above you will hit what is called the dew point. This is where the water vapour turns from a gas into a liquid. Now when the insulation is only 100mm thick this won't happen very often. The water gas will keep migrating into the roof void and escape more easily. The insulation will get a bit wet from time to time but it often dries out in an old roof. The techy bit is called the dew point. This is where the water gas turns to a liquid. Like when the gas in the clouds turns to water and it rains. In the thinner insulation the dew point will occur less frequently and the gas will just exit the roof more often without causing any harm. But to bring a roof up to modern standards we are looking at (350 - 400 mm in Scotland) and a say 300mm in England, this insulation comes in standard thickness. Here you can see that the loft will be much colder as you have added insulation. As the insulation is thicker the dew point will occur more often within the depth of the insulation and the insulation will become wet more often. Wet insulation against a timber roof don't make good bed fellows. To solve this we need to make the roof void much more drafty.. by installing more roof vents so it dries out the thicker insulation and reduces the time that the roof timbers are exposed to moisture. The big problem with this is that the foil is impermeable. We know that at some point we will get the water gas turning to water drops. The foil stops this water from venting out into the loft and then out the roof so it is trapped and will rot the timbers. @webbythewebster To upgrade the loft insulation, it sounds counter intuitive, you need about 300 to 400 mm of glass wool and then increase the ventilation to the void. The loft will become much colder, but the house will be warmer. Here is a link to a free calculator that you can play with. It also chucks out a basic condensation analysis. https://tools.knaufinsulation.com/en-GB/tools/u-value-insulation-calculator But why is this product to be treated with extreme caution! Basically, because if it is laid on top of insulation is stops the water that has condensed within the insulation and then turned back to a gas when the weather warms up (evapourated say) from getting into the loft void and out the roof. For all, and the teckies. At some point many buildings will, depending on the weather get condensation happening in the depth of the structure. If we try and avoid all cases we end up over designing and that costs you money. For the really tecky we have what I would call a reverse condensation effect.. few if any condensation models take this into account. Your house outer pane of glazing is cool, a warm weather front moves in from the west, it's misty, you can see the mist with the eye. This mist / humid air penetrates the wall and condenses from the outside in! @webbythewebster To save money the easiest target is the loft. But you need to ventilate more. Have you explored whether your Dad can get a grant for this work? RICS Spray foam insulation downloaded 31-10-2025.pdf

Good point John. If you have a deep (thick roof) then the reveals can form quite a large area. The closer you get to the top surface of the roof the less effective thickness of insulation.

I bet it did! Took me ages to find this data also.

Welcome to Build Hub. This is a massive step forward. You'll get lots of help here as and when you need it. These type of projects are fascinating, even just from an engineering aspect and how you evaluate the existing building in terms of what you can retain structurally. Photographs and a couple of concept drawing will encourage targeted advice from members. Main thing is to enjoy the design process.

I think you have done well exploring this. Yes you can design this SE wise, maybe achieve a weather tight arrangement. But now I've read others opinions I'm inclined to say, I've learnt a bit more and now also concur that you should look at alternatives. Keep us posted though!

Avoid, it's a gimmic!

But I posted a long rant on how you do it as an SE, it's not that difficult! If another SE reads my posts all they have to do is look up the references I give, make their own judgement on the geometry of the roof and off you go! It's 3 hours work checking / learning that I'm not talking shite (call that research that will add add to your portfolio) and looking at your drawings. Then you go back to the PV designer to check their brackets are ok, do the rest of the checks for due dilligence. The key is to identify the pressure coefficients. For the house design the SE has probably worked out all the wind loadings already! This sums it up plus, as I said previously, the PV needs to look good Architecturally, you can't have a big unsightly gap at the ends for example. The detailing and weather proofing needs to be spot on. Keep asking your welcome questions so you can make an informed judgement.

Thank you for posting and asking questions. It keeps BH alive! In no particular order. True enough. We are both experienced in design, have much common ground. @saveasteading has more than a decade of design experience than I. But it's ok to sometimes disagree. You present / argue your case. You bring to bear specialist knowledge and sometimes that sways the case. Good designers learn every day, age is not a barrier, new materials are on the market so the choice of material is more varied. It's a great time to be a designer! But if we never disagreed that would be unheathy. Check the privacy regulations for your neighbours windows. Often you need to add 2.0m plan distance for every 1.0 m change in level. Just check even if to rule out as a consideration. I've attached a handy guide that is easy reading with lots of visuals that explain daylight and sunlight. Don't discard this on the basis that it is from a Scottish council.. the principles apply UK wide. Daylight and Sunlight guidance 17-06-21.pdf