Hi Jill. Thanks for your input. I completely agree with your point that a moisture meter should never be the only piece of evidence used. I hope the demonstration has not given that impression. However it can be used to help quickly establish the patten of damp to assist in isolating various forms, and is very useful on basic visual only inspections to draw a surveyors attention to where evidence may have been covered over. From that perspective, I would not relegate it to the last port of call. I do agree that if someone is doing a building pathology exercise they should have much more evidence and equipment to accurately diagnose. Sadly this is often not the case. Thanks again for raising this very important point

Can you expand on your question. I'm not sure the scope of the video includes remedial actions. You would need to refer to BRE digest 245.

Glad it was helpful!

If the condensation hangs round long enough it can skew readings which is why you need to take a comparative reading. A lot of misdiagnosis of rising damp is caused by things like condensation. You often see videos of people lifting the plaster to find dry brickwork beneath.

Thank you. There is a lot of disproportionate misinformation as to the use of moisture meters so its as well to read widely and take a view as to when to use one rather than follow an ideology.

Yes I agree.

I have to confess I was one of your students at Cirencester summer 2022!

Yes, I think roofers might take a number of views.

From the perspective of a surveyor, a company that adhere to the British Board of Agrément (BBA) standards, including the provision for full encapsulation of the roof structure, is a matter of both compliance and quality assurance. However, it's not as straightforward as it might seem. If a company follows the BBA guidelines rigorously and implements full encapsulation of the roof structure along with a vapor control layer (VCL) (Only HR roofings underlays) using the paint method, one might presume that surveyors should approve these methods based on their adherence to recognise standards From my viewpoint, the concerns extend beyond the technical specifications of spray foam insulation. They also touch upon the interests of surveyors and their professional associations. The requirement for full encapsulation of the roof structure, accompanied by a VCL, does not directly benefit surveyor businesses. I do think that can potentially impacting the demand for their services. The United Kingdom boasts a significantly high number of surveyors compared to other countries. For example Germany has approximately 1,000 ( RICS) individual surveyors, suggesting that the prevalence of professional residential surveyors and the issues they encounter may be lesser in magnitude there. This disparity raises questions about the relationship between industry practices and the perceived interests of surveyors. However, the potential for perceived conflicts of interest, stemming from the economic dynamics of the surveying profession and its business models, complicates this issue. It suggests a need for ongoing dialogue and collaboration between installers, surveyors, and British bodies Codes to align technical practices with the overarching goal of maintaining high standards of building performance and integrity. Despite many surveyors cautioning against spray foam, it's crucial to acknowledge the impracticality of a trade meeting everyone's standards. Properly assessing spray foam requires an understanding of moisture management and the underlying science. I've never saw a profesional surveyor providing a condensation risk analysis or, when necessary, recommending a Vapor Control Layer (VCL) or ventilation system. This highlights that the issue extends beyond just untrained installers; a lack of knowledge among professional surveyors is a significant industry problem. Without delving too deeply here, to illustrate: a recent email from a customer relayed a surveyor's claim that a product felt soft because it had been diluted with water. The surveyor, likely familiar only with closed-cell foam, misunderstood the natural softness of open-cell foam so he questioned the integrity of the installation company( BBA approved ) saying this ( -a clear misinterpretation, Great example off inadequate industry understanding. -I've seen a video where you discuss using a combination of open-cell foam and fibreglass, which can lead to what's known as a double vapour barrier, particularly when leaving the fibreglass in place at the ceiling levels. Interestingly, it seems we're unique in the UK for keeping fibreglass at these levels, and this practice largely stems from the constraints placed on the UK spray foam industry. According to section 9.1.10 of the BBA ( in England and Wales, roofs and loft spaces are deemed to adequately limit the risk of surface condensation as long as the thermal transmittance (U-value) doesn't exceed 0.35 W·m^2·K^−1 anywhere, and the connections with other building parts are designed following section 6 of this certificate.) For spray foam businesses aiming to adhere to this clause, we find ourselves forzed to leave the fibreglass in place at the ceiling levels, us included. This necessity arises because, with just 100mm of open-cell foam application-which is often the max we can apply due to rafter thickness and its thermal conductivity being around 0.038 W·m^2·K^−1-just the foam alone isn't enough to prevent or eliminate surface condensation. Thus, the presence of fibreglass must be considered in our assessments. So, we circle back to the same dilemma. If we're to follow the guidelines to the letter, achieving compliance across the board is challenging. It won't be until third parties fully understand the science behind what we do that we'll see progress in resolving these issues. Remember how, over a decade ago, British homeowners faced difficulties selling properties with cavity wall insulation? At that time, thousands of homeowners struggled to secure mortgages due to the insulation in their cavity walls. It turns out, the products weren't the issue. This presented a challenging period for the surveying industry, which found it difficult to assess cavities after they had been filled. Today, however, inspecting filled cavities has become common practice. So, it's clear that spray foam isn't the first product to encounter skepticism. Now you might be wondering, how do I judge surveyors? It's simple. I see the surveying industry as quite vulnerable. Universities are still teaching moisture management using methods from the 50s, like Glasser's, but the dynamics of properties and insulation products have evolved significantly. And from what I've seen, spray foam isn't straightforward. Sometimes, not always, but sometimes, I hear surveyors getting it all wrong about spray foam. And from what I know through experience, when new products are tested by manufacturers, they don't often think about educating surveyors, training them, or providing them with the resources to assess such new and complex products. Building science and spray foam science are just on two different levels. I can understand some of the misconceptions. That's why this is my second time responding to a video from a qualified surveyor. The first time was because he used a picture of my work from 2020, which was professionally installed. I want to Thank you for your time reading this comment. All the Best Mr Geoff Kind Regards Adrian Fernandez

A very interesting read. I agree that what spray foam does to the dynamics of a roof are very complex which is why it is difficult for residential surveyors in the UK to evaluate the likely forward performance when assessing a home for lending purposes on a visual inspection basis only. This critical point seems to have been overlooked by those entering the market when deciding their distribution strategies. Instead of demonstrating skill and judgement of the requirements of the BBA and KIWA certificates and selling it professionally most passed all responsibility to small teams of contractors, who subcontracted direct sales firms, who cold called homeowners and mis diagnosed the install. I have to disagree slightly with your assessment of the BBA certificates. They are (and there are many) the ones who suggest BS 13788 (the Glasier) model as the first test of a risk. This is a far too simplistic a model which can easily be manipulated to produce a positive result by selecting a nominal value for the vapour permeability of bitumen underfelts. This should always have been recognises as an Achilles heel by the BBA and KIWA in my opinion. The historic wide spread use of bitumen in the UK is another factor that has caught many international supplies on the back foot. The attempts to impress surveyors that this could be an acceptable application in a climate such as ours has been unimpressive and I have to say one which still seems unacceptable to many surveyors in the UK. Finally you may be surprised to hear that there has been no formal guidance from any surveying organisation or government to assist surveyors, hence the lack of knowledge. Any group that has tried has been issued legal letters which has not developed a free and safe space for surveyors to openly discuss the issues. I thank you for your observations. you too seem to have a very good grasp on what is happening. it would be great to discuss this further with you. This is my opinion only not the views of any professional institution I am a member of.

Thank you for your thorough response, Mr. Geoff. I wholeheartedly agree with your insights on sales strategies. However, it's unfortunate that the spray foam installation industry seems to be inundated with numerous franchises aggressively promoting their services and products. Personally, I don't endorse this approach to conducting business. It appears to be ingrained in the business culture, especially in Britain.Similar sales tactics are prevalent in the home improvement industry as well.Spray foam holds tremendous potential, especially when we examine the data on how homeowners are living. It's evident that air-permeable products alone aren't sufficient to meet new standards. While surveyors & Government may suggest that 300mm of fiberglass insulation on ceiling levels is adequate, homeowners increasingly prefer more effective insulation systems for better performance. There's no need to resort to high-pressure sales tactics; the product should speak for itself. Regarding BBA BS 13788, it's crucial to acknowledge the limited vapor permeability of bitumen felts. Through thermal modeling calculations, we've seeing that some water vapour can escape from the overlapping of the felt. Dynamic calculations have shown this phenomenon occurring in certain regions of the UK, primarily in the south. You're correct in pointing out the potential manipulation of static condensation risk assessments. Various factors can be adjusted to favor certain outcomes, such as altering water vapor permeability or changing the center of the rafters or the thickness of the bitumen felt. It's important to clarify that spray foam holds certifications for application into HR roofing underlays. In contrast, rigid boards, for example, do not support this application. Therefore, there is no certification supporting the application of Rigid boards into retrofit homes where HR roofing underlay has been fitted. Hence your comment reflecting the truth. Please allow me to correct the understanding regarding BBA's recommendations Regarding HR certification and BS13788. While it's true that the BBA recommends following BS13788 standards, it's essential to note that merely adhering to static calculations is insufficient. BBA explicitly states the necessity of providing a dynamic condensation risk analysis, also known as hygrothermal analysis. This sets it apart, as other assessments, like BuildDesk, have their limitations, such as the inability to assess product airtightness. Dynamic assessments can be conducted using tools like WUFI for thermal modeling calculations. BBA certification is closely tied to documents like these. BBA employs external independent companies to conduct assessments, which span 5-20 years and comprehensively manage moisture within the roof structure. These assessments also evaluate risks such as rotting rafters within a long period of time. I believe you have been in touch with Richard Yeo regarding this type of Calcs, he is the right person to discuss the assessments. BBA's stance is clear: while dynamic calculations demonstrate the suitability of spray foam applications on bitumen felts, a vapor control layer (VCL) must be integrated to maintain the dew water threshold at 0 kg/m³ across all UK regions. This requirement is clearly outlined in their certification.( The answer to this in my previous comment) I understand your concern regarding the importance of clear communication within our industry. Experienced installers should be able to discern discussions about our field. From my perspective, there seems to be a dual issue at play. It's not just about uneducated installers improperly applying spray foam, but also professional surveyors recommending its removal without adequate knowledge. This results in homeowners wasting significant sums of money and enduring unnecessary stress due to misguided advice or decisions. This cycle needs to be halted. The notion of a blanket ban on spray foam is not entirely realistic. For instance, we've consistently been able to assist customers in selling their properties despite challenges. Some lenders, like Halifax, have proven difficult to work with due to their reluctance to listen and learn. However, by presenting sufficient evidence of compliance, we've been able to sway their stance. It's essential to address these issues and foster better understanding and cooperation among all parties involved. It will be my pleasure to keep in touch with you. please find my email [email protected] Regards Adrian

I have for building pathology work but not residential surveying as it requires drilling holes. The speedy carbide moisture meter is probably the next level but is also prone to mis interpretation and over qualification. I have found that with accurate assessment the digital meters can be used to move straight to gravimetric stage to eliminate free air form the assessment. When assess the causes of damp penetration there are so many other observations that are needed for assessment. There is no single test that is more accurate than the other to give a definitive answer.

I'm a structural engineer and have come across quite a few instances of roof spread. Geoff said you could consider strapping and I would use to 30x5 straps used for holding down rafters etc and place at 45 degrees to connect the rafter end to a ceiling joists ad do that every other rafter. I also suspect that the wall plate has a gap underneath it and only part of it is bearing on the brickwork. I would either pack with dry pack mortar or resin injection if the gap is too small.

Hi Craig. As I suggested in the video it is possibly static and to reduce or contain the risk some form of tie beam could be contemplated. I expressed the opinion the evidence suggested it was a low risk overall.

Thanks John great insight

@@geoffhunt6646 Hi thank you for the reply, so possibly CR2, can I ask did you advise that a structural engineer needs to be involved for the specification of the tie beam(s) and although low risk did you give an indication of timescales for remediation ? Apologies for the questions, its a good video and I am interested in this topic.

@craigsmith3954 when I look at these cases when mentoring on line we talk around various scenarios to stretch your thinking. But each case needs to be taken on merit but I was of the view that the situation was static but that any perceived risk could be controlled by a tie beam. I agree with you that if you were using the category system I would put it at Cr2 ( I'm not a fan of ratings so would not put it very prominently). As for structural engineers I wouldn't because a tension tie beam in timber doesn't need too much calculation and the risk is quite low. A good roofer would probably over cook it in any case and a "warranty" would be fairly trivial.

A great point form a different angle and very valid. I fear the vast amounts of investments embedded into the products we use today may deafen the main players to your sincere calling. These types of product are not only in construction but literally everywhere. Thank you though for reminding us that we only have one planet. A nice warm house on a dead planet isn't of much use.

I have come to recognise that by not understanding the true nature of the supply chain when products are directly sold to the public the government makes a recurring critical error in delivery of what should be a worthy initiative.

A good spot. Many small builders do not appreciate this type of movement needs to be accommodated.

Good spot. I think that rule and not propping open fire doors is the most common of infringements.

An interesting point that speaks to compliance to guidance and any actual manifest problem. As surveyors we have to take the visual evidence and give a reasoned assessment of the risk. I am not aware of the full guidance of requirement for node support but bracing of trusses was generally introduced across the UK to regularise installations. It is often an over design in low exposure areas and therefore we would need to see evidence of a manifest ongoing problem before we raised reasonable concerns. We would raise any issues with non compliance but in context of the overall apparent risk. If any risk needed to be reduced, in my opinion, advice could be given. A very good spot. I assume you are a roofer or designer?

Oh yes. The meter is only an indicator. It's not a definitive result. There are many reasons why moisture might be in the wall. It is also only a snap shot. The moisture in walls fluctuates seasonally.

absolutely. the classic moisture meter false reading.

Yes Turner went through a mould phase but it was not well received in Paris so he ditched it.

Glad you liked it!

Yes it is true that many green initiatives have suffered because of pop up firms who go into liquidation and direct selling by third party sales companies who have no experience in the consequence of poor initial assessment.

Hi. Thanks for watching. In terms of the wall I only used it for demonstration purposes. I happen to know I have a higher spot on that wall as its a single skin garage wall with no DPC. Technically speaking you can put render on a cavity wall because the inner should be separated by the outer. That's not everyone's point of view and lots of people quote the 150mm minimum clear brick to ground level because it is thought that covering the dpc with render creates a bridge. In my experience it does bridge but it takes a long time to become manifest. It's different for solid walls where keeping the dpc as clear as possible is the best plan. Water is a complex chemical so if it can get in it will. Check out NHBC details as they are generally accepted as industry standard even if they don't care to check its built like that!

Although it is hard to diagnose on here I want to see if I can steer you in a good direction. You sound as though you are doing the right things. Get a temperature humidity meter and check what the temp is before you use the kitchen. Try to get close to 21 using the programmer. Don't leave windows open in the winter too much as ventilation sacrifices heat energy. Try to balance energy in the wall and air and the amount of moisture in the room where mould is growing. If you have a cooker hood that might not be an extractor so check that as it might not be helping as much as you think. I hope you can start to get the balance right.

I'm glad you liked it. Are you dealing with mould at the moment?

@@geoffhunt6646 ye

Yes I've just had room treated. Difficult to know in a leased accommodation that I've bought(retirement)who is responsible to pay for putting it right?I pay high maintenance fees annually and told when I purchased I only need contents insurance. Can you advise. Please.

@elainewhitelock5347 well basically condensation happens all the time and as long as it dries out there is usually no problem. In the room where you have a problem you need to work out if there is enough heat ( 21 degree C in the day) and how much moisture you are creating. Each room is different. Buy yourself a thermometer humidity meter and the humidity needs to stay around 50 to 70. If its low temp try lifting it when you use the room and if it's high moisture then ask your land lord to check fans have good ducting and work well. In the summer you can open the windows to clear the moisture but keep doors closed until the condensation has cleared. If it is a leak that will look like a stain in a specific place and often gets worse when it rains. That should be fixed by the land lord but always manage your condensation as the two are often not linked. I hope that helps a bit for you.

@@geoffhunt6646 thank you. That info is very helpful. I will certainly address this issue with your suggestions . I think it may need to improve the heating level . Much appreciated.

Very welcome

Hi. These are walls I have come across in the UK. I mainly work in the south west but some photographs were taken when I was on my travels.

@@geoffhunt6646 Ah, lovely. Thanks for the reply :)