Hello Frances:

I have never seen anything that covers the risk of developing mold in houses.

I have had mold develop on the ceiling of one room in my house, here in Florida in the wintertime. I solved that problem by (a) painting the ceiling with paint that contained a special chemical, (b) adding insulation to the outside of the house (c) adding insulation in the attic (d) upgrading to a heat pump.

If flooding of the house were to occur due to storms/hurricanes during summer, then mold will form on the walls within a few weeks and there is nothing one can do.

Peter Brooks

Palm Bay FL.

I did the calculations at college around fourty seven years ago, when I did the City snd Guilds Construction Technician course and gained the qualification, including calculating the probability of black mould developing in a corner of a room. 

It was something I was going to get back up to speed with some years ago when the Domestic Ventilation Competent Person Scheme was launched and a few years later I bought a combined laser thermometer and humidity meter, which will test and determine it whilst on site, it is in with my air flow anometer, I will try and show it to you later.

I ended up installing lots of extractor fans, as I worked for walk in bathroom companies for nearly seven years and other customers, including landlord, but didn't do much black mould investigation work.

But there are certainly things one can do to avoid making it worse, mainly monitoring humidity and encouraging air exchange at times when the air outside is drier. Heat recovering trickle vents are expensive compared to simple fans, but are less likely to lead to cold spots,  Generally houses in flood risk areas will be solid floor downstairs, and things like tiles and painted render inside, instead of carpet and wall paper. Cavity wall insulation closed cell foam rather than rockwool, that sort of thing. (only if it is young enough to have cavity walls at all of course.)

Not sure how much understanding is new but there are certainly courses on how to do assessments.

https://ukcmb.org/training-and-cpd/ for example - their diy on line calculator seems to be broken so that cant be tested right now.

Mike

I have an interest in indoor environmental mould risk calculations.

Depends on quite what you're interested in calculating - the humidity/temperature that gives a dew point which can lead to mould, or the probabilities of mould occurring given less precise data, or the probability of harm etc. There's quite a bit out there on preventing condensation - e.g. I think passiv haus had a formula for preventing condensation (which given a few assumptions comes up with a U value of 0.8 for windows etc.) and I suspect similar can be found in most ventilation and/or insulation guides.

- Andy.

Thanks Mike,  the 'use case' for detecting conditions that could lead to mould development is a commercial one. We already have  regular  temperature and humidity reading data for the environment, keen to explore how to use science to indicate if there's a risk of mould developing. 

Thanks Sparkingchip, I'll take a look at the DVCP scheme. The use case for what we're looking at is commercial in lots of residential spaces.

Thanks Andy, I'll take a look at the passivhaus trust website, not one I'd heard of before. 

Thanks Peter, the use case for what we're trying to do is large residential properties, we have temperature and humidity data, keen to explore if science can help us detect conditions for risk of mould development. 

certainly you should be able to - the humidity is most important, and that is affected by temperature as that relates to condensation risk, but ideally also you need to have ventilation rate information or a model - or you will be identifying all 65% plus humidity areas in a building as being at risk, not just those with a lack of air changes or warm temperature..

See https://support.conserv.io/knowledge/mold-risk-kpis as an example

I have a Extech IRT600 Daul Laser Infrared Thermometer with Humidity and Dew Point test meter.

Extech Instruments is a Flir company, the tester is now obsolete and I can’t see what, if anything, they have replaced it with. It is literally point and test, with a screen displaying information and a traffic light green, amber and red indicator lamp above it.

The tester gives a quick and clear visual indication of where black mould may develop, particularly in corners of rooms and helps to explain black mould issues to people.

https://www.coleparmer.co.uk/i/extech-irt600-dual-laser-infrared-thermometer-with-humidity-and-dew-point-12-1/8653108

It is part of the Domestic Ventilation testing kit I have, along with an air flow anemometer and moisture meter.

I have a couple of books, but I can only find one at the moment, the Dri-Eaz Restorative Drying manual, a good general reference, but over sixty quid second hand on Amazon, reference books are expensive!

https://www.amazon.co.uk/Guide-Restorative-Drying-Dri-Eaz-Education/dp/0977670104

Best of all, one of my neighbours was the National Franchise Manager for an insurance remediation company and he was a great source of information, if he didn’t know the answer to questions about drying buildings out after floods and leaks, and preventing black mould developing in the meantime, he knew someone who did, but unfortunately he has now retired