Dealing With Damp and Condensation 

I like the fact that Mostyn doesn’t know the cure until he has looked at the problem, unlike some. It’s also important to say “you don’t know” every now and again. That’s the sign of someone who knows what they are talking about.

These videos make you feel that you are in the same room as the guys discussing your building projects. Thanks for all the practical advice

Just had Mostyn visit our cellar at our high street shop in South Cave. Great guy, spent time inspecting the area properly and we look forward to having him undertake work to alleviate condensation we have in the cellar. Another great video Roger. Mostyn gave this a share to me 👍

Open up your fireplaces, fit in-line fans in bathrooms, open your windows and trickle vents, use your extractor fan when cooking, don't dry clothes on a radiator - there's many simple things you can do to air your house and prevent damp and mould. We swapped out a tiny ceiling extractor fan in a bathroom with big in-line fan that extracts 3x the cubic volume, it's so good the mirror doesn't mist up when showering.

I installed a Nuair unit in a rental property a few years ago. It is no exaggeration to say that the condensation problem was cured overnight permanently.

One of your best videos yet Roger, thank you. Mostyn is clearly an expert. I've fitted Drimasters and they certainly work.

At last someone who understands hygroscopic salts on you tube! I once went to a chimney leak, all flashings slates etc no problems, mushrooms on the pots & vents in the blanked off fireplaces. we eventually pulled out 10 rubbish bags of old jackdaw nests out of the chimney! the sweating brought the salts through. sorted with K11, never a bother again, the customer admitted that we were the 7th firm who had had a go at fixing the damp problem! builders need to be more aware of salts as they will send a damp meter off the scale & its only in the top 3mm.

I T is a truly joy to hear this person-guest you interviewed-spoke with....he is personable, open to hand information out, full of effective ideas on how to solve these issues. Thank you for informing us-me and educating us-me.....What is the name of this wonderful Contractor?

I had lots of condensation in my new 1910 house. So bad the paint on some walls was lifting and mould growing. I fitted a PIV this last weekend and within a day the windows are almost condensation free. I can’t believe how quick and effective this solution is. It’s probably reduced the problem by 80% in two days.

Great discussion ive got 3 bed house with 2ft wide walls. wet walls put ebac dehumidifier top off stairs was pulling 2.5 litres a day now full every few days, house is alot warmer .

ROGER, what a fine interview. I'm offering you a sincere "Greetings" to you, from the colony; Canada.

Great Episode. Clear discussion on one of the most moss understood areas of how home ownership and renovation. Well done

Great vid. Great to hear Mostyn talking the holistic approach to dealing the damp/humidity and condensation problems.

Thank you for this video. I've learnt so much here and have booked an appointment with Mostyn. We have a grade 2 listed Cornish house and this information is vital!

There are too many “damp proofing companies” that come to the house, take a look and say that’s rising damp, it needs hacking off to 1.2m tanking, injecting and re plastering. There are too many courses like that, they don’t teach you about how damp works. I have condensation and I had a guy try and tell me I need to have all of the above done when in fact, I don’t. Great tips, I am definitely looking into the Drimaster. Thank you very much

Excellent interview great to listen to people who understand the systems and problems they are dealing with

Good interview Roger. It amazes me how little we really know about resolving rising damp and condensation issues. The money that goes into quick fix remedies is preposterous. We have the same problems here in Italy, especially with rising damp. Millions are made with quick fix solutions, you'll find the problem returning a couple of years later. I've resolved condensation problems in my house by adding false ceilings and installing insulation in the voids. It's a simple process with good results. The rooms are much warmer and the ceilings aren't cold to the touch. Basically i'm trying to control the dew point as much as possible. This has made a big difference, especially in the bathrooms. Adding extractor fans in the bathrooms with humidistats are also a must. If And of course taking the necessary steps like not drying clothes in the house. Steaming kettles and cooking pans with hot water can be resolved by an extract fan over the cooker that expels steam directly outside instead of relying on the usual filter. The big problem here in Italy is rising damp. Most older houses, which there are a lot, have this problem. Our house has it on all the ground floor walls. A couple of years back i removed the plaster on one of the walls in the entrance to our house, it was bad and very unsightly. I removed the plaster 1100mm from the floor. Most of the bricks were damp. I let it dry out intending to plaster over it but it actually made a nice feature so i left it as it was. To this day the dampness has gone, or evaporated. There's a big deal over here with using breathable plaster and paint. That's the direction i'll be heading when i start renovating the ground floor. That and the Dryrod system that i saw on one of your videos. Keep up the great work

Really insightful conversation from both so thanks for sharing on the topic.

One subject that has plenty of room for more comment. PIV is the simple answer in so many cases.

The dri-master is possibly the best purchase I’ve ever made! Good to see they are still well regarded

One of the most important things to get down humidity/Condensation is to remove it quickly from the source area ie Bathroom Kitchen, put lids on pans try and get humidity sensing extraction fans in those areas and it will cut down the humidity also shut doors in those areas when in use to stop the humidity going in the rest of the house, open back up when the humidity sensing fan has stopped.

A great posting and an interesting guy, specialists in their field are always handy. Since you insulated my house the upstairs bedroom window reveal has gone black. Wow I'd best have a look at that. It was easy to see the ill fitting window at the bottom of the hinge side. Most of the Blackness was Traffic dust not mold, but mold was present up the reveal as this was also creating a cold spot. A glass lifter and some WD40 might save the day as you can lubricate the hinge and use the glass lifter to pull the hinge end into place and stop the draught. Generally if they have been stuck ajar in the bottom corner dust build up on the hinge can be huge, so watch out for it blowing back at ya.

brilliant video, I had big condensation issues and this interview is GOLD ! I did a lot of research over a year ago and bit the bullet and ordered a nuaire drimaster and fitted it myself which isn't that difficult, results are fantastic in controlling condensation. only slight negative of them is that it 'slightly' lowers temperature on landing but that is a small price to pay for reduced condensation.. keep up great work Roger

Very valid points lots i see is actually condensation with no air circulation so.👍

Hi Roger, that was a great interview, really enjoyed it. The eternal battle of insulation versus ventilation is a really interesting one. if you want to see the extent to which salt attracts mositure, go outside on a cold day like today and have a look at a road that has been gritted by the council. Even if there has been no rain, snow or whatever, the road will likely be damp: it's the salt in the grit drawing mositure out of the air. On very cold days with very low humidity and very dry air, the road salt will be dry and you'll see a white powdery coating on the road,. But for the most part in the UK we have pretty humid air so gritted roads look damp. You can often see it on pavements alongside gritted roads, too. You'll see lots of small damp spots on an otherwise dry pavement. If you look closely at the centre of each damp patch, there'll be a grain of road salt, which is sucking moisture out of the air and making a damp patch around it. I was showing my daughter only a couple of days ago as we walked to school, but she wasn't in the least bit interested because she's only eight. Thanks very much for all the great content, keep it up.

"Salt retardant treatment"! Salt coming out of the walls! This man is a star! Huge thanks Mostyn! Mine's got no damp course, built around 1860, on a salt marsh. Badly refurbed by a Housing Association over 20 years ago. With busses jumping over the road humps outside. It's a really good tiny house, it's just been badly treated. It's been a journey. Thank you for all of your wonderful videos! Borax by the way for black mould. Not bleach. And ventilation.

Excellent video, well presented by two Master tradesman technicians....Well done

Thanks to the both of you for taking the time to video this..really informative..

Excellent video Roger and what a nice knowledgeable guest.

I fitted one of those units not long ago for a couple and they said it helped no end with the damp.

Thank god for this video. Checked comments, got myself a nuaire drimaster. Perfect. Windows have minimal condensation on now in the mornings compared to the full window dripping. No wet walls and ceiling on the bay window anymore. I'm guessing no more mould

I love Your curiosity and persistence in research ! It is inspiring.

I had a piv or what ever its called fitted all I can say my house was nice and cosy and warm now it's soo cold the air pumping in is soo cold so I went into the loft turned it off and blocked it off now my home is nice and warm

Bless you Roger .. you’re a star ⭐️ ..

This guy is clearly very good.

Fantastic video, very informative. Just in the process of buying an old 1920's property. The home buyer report referred me to get a damp and timber survey whose representatives came round and quoted £7k for a damp proof course. Never one who wishes to pay for my ignorance I have been doing my own research and came upon your video which makes so much sense particularly around lifestyle in relation to condensation being a key problem nowadays. Hope I can find some decent tradesman ;like you guys as things progress

Great to see you changing your damp attack tack! It’s a learning curve my man and each job teaches you more. A lot of good stuff here 👍🏻

Totally agree Roger,people don't put their spending priorities in the right order, nothing worse than damp and mould!Government incentives waste of time in my opinion.Great video!👍

Great advice as usual. Thanks Roger.

I had same problem, my tenants had an electric heater in the bathroom, and an airer dull of washing. The ceiling went black with mould, they reported me to the council and they explained to them what they were doing wrong. People don’t understand the consequence of their actions

We had that issue in our house - mould growing around the windows, patches on the ceiling etc ...being amateurs we jacked up the heating, replaced the double glazing and doors, shoved a flock of sheep in the loft...and made it worse. Then we looked at it from a different angle and started to reduce the moisture in the house by any means we could (including opening the windows for 15mins a day in the winter). It's pretty much eradicated it apart from an ongoing issue in the kitchen but that's to do with shoddy fitting of the extractor and is a whole novel in itself. Love the channel - by the time I've watched all the videos I might actually have a handle on how to fix the 'Money Trap' :)

Another great vid packed with useful information and food for thought. thank you. I'm not convinced by the Drimaster - 400 W running maybe 24/7 adds up to a potentially high electricity bill.

roger love your channel please keep it up and can you always ask Mostyn to join you with a problem he knows what he is doing he is one of the good guys 9n this damp industry

I like this style of longer format videos

Mostyn Neylon-Witham knows exactly what he is talking about totally agree with him

This was brilliant so much knowledge and expertise between you , absolutely loved it

Fitted a PIV in a single block house that the walls and windows streamed with water. Within a week it was all gone. I was genuinely surprised and a fantastic purchase I made

Over the past 10 years I have renovated over 50 victorian property's in Liverpool, there hit and miss with condensation problems, these houses where not designed for modern living, sash windows where dehumidifiers in themselves and when double glazing was introduced the condensation in these properties just go to the external walls and cold spots, especially if there solid render and plaster finish, I knock all external walls off and replace with therma plaster boards with secondary fixings, I also put trickle vents in the sashes on the pvc windows, now I do install the heated piv system in the loft as standard, I do all dpc as standard with dryzone, great product. Drying cloths on radiators, madens, is one of the main problems. Also if anyone has condensation issues try not to use matt emulsion as this just holds moisture in the chalky paint a vinyl matt is much better.

I always use the rice in salt example myself - it's a good one for people to relate to.

Excellent video Roger. I wonder how much condensation dampness (possibly to residents below) is caused by old weeping plastic waste or galvanised steel water pipes (poorly) imbedded in a concrete floor e.g. pipes placed on a concrete purlin floor, with a thin concrete screed on top?

In my old house we chased damp and every firm (free surveys) we had said we needed injections, we had it done and it made no difference. We found a company that charged for the damp survery and they said the problem was a badly laid concrete floor which had replaced the original suspended wooden floor. When we dug it up we found only about an inch of concrete with just rubbish infill underneath and a bit of roofing felt round the edge as the damp proofing. In addition we found open air bricks below ground level. New concrete floor, blocked up air bricks and it was cured. My lesson is you get what you pay for, and a free survey is just a sales pitch.

seems to me the sooner we build houses using straw bales and lime plaster the better. Your right about peoples priorities, eg, our choir would put on a concert and say charge about £5.00, people would moan about the price and yet during the after glow in a local pub the same people would be quaffing double whiskies like they were going out of fashion.

Noticed staining and black mould on an internal painted wallpapered chimney breast in an unused upstairs bedroom and on the ceiling area adjacent to it. Fire place in the bedroom long since bricked off. Roofer 1 suggested fitting new cowls and he checked the chimney's external flashing. Roofer 1 retired. Staining continued to expand. Roofer 2 thought that blown harling on the external chimney might the problem and replaced this. Staining continued to expand. I decided to strip the wall paper off the internal chimney breast to see if that might help inform source of the damp. Was shocked and appalled at the extent of black mould under the wallpaper and how damp the plaster was. Roofer 2 now suggesting condensation. Bought a dehumidifier and left it to run in dry mode continuously. I'm gobsmacked at how much water this collects - average 4 litres a day! Also blowing a warm air fan onto the chimney breast. 3 weeks of this and still a couple of damp patches on the chimney breast (some of which expand if I turn the fan heater off). Still not 100% convinced it's condensation and not a leak from outside. Is there a sure fire way to test for this?

Exceptionally informative. Thank you.

Excellent discussion. Thank you!

We've had damp in one area and it became apparent it was a blocked down pipe from the gutter. The survey didn't pick it up. We noticed it after a downpore, luckily before before the damproofing was due to take place. A new soak away saved use a lot of money. Well not that much but the appropriate action was taken.

Thanks guys, wonderful interesting video. Humidity is almost always very confusing. We live at the coast and always wind from the South-West. Guess witch wall / woodwork gets the most damage from water. I will look at this storm-dry thing. Measurement is gold. Installing wireless sensors for temp en humidity and recording this for longer time, would help to proove. Solution can be difficult. Floor / walls / windows / ventilation have to be looked at.

Dehumidifier is the way to go warms the room as well. Outside air can have more moisture in than inside the house so putting more in.

You can also get heat exchange PIV units which pass warm air from the house across a heat exchanger to warm the fresh incoming air before it is expelled.

My PIV is brilliant, the window vac is back in the box and it was used every morning on saturated windows.

My bungalow was so bad humidity so high tha nails on the skirting would show through with rust the windows would run with water so bad that we bought a window vac for the windows in the mornings, the double glazed window all had trickle vents nothing helped, towels on the sills to save the floors I FITTED A P.A.V. NUAIR ITS THE BEST MONEY I HAVE EVER SPENT AN HOUR TO FIT AND THE FOLOWING MORNING AFTER A FROSTY MORNING, NOTHING ON THE WINDOWS, NO MORE MOULD IN THE BATHROOM, BETTER NIGHTS SLEEP. 75% - 48% HUMIDITY 👍MANY MANY THANKS 👍

Thanks for the brill discussion. I don't have damp but still considering a piv

I've found a lot of issues have occurred in the last 18 to 24 months - i've related this to the pandemic and working from home. Suddenly these properties which could equalise but not being occupied 24/7 are now being occupied 24/7! so people breathing, making coffees all day etc and problems arise.

I fitted a nuaire drimaster eco heat to my house 3 weeks ago and it has literally changed our lives over night. Every window would be dripping wet and within 24hrs they were all dry even with the curtains closed.

My sister lives in a 300 year cottage and its riddled with damp. Think shes had every damp expert look at it and she has had numerous work done. She has the extraction unit fitted and its not gone, will show here this video about positive air flow. Apparently there is a old stream that runs under the house but unless she knocks it down we will never know

What a brilliant video, great watch

Excellent video!! Well done guys. 👍👏🏻

storm dry is the only product in is own class as it also gives a thermal value to the wall as it carries on absorbing ,awesome product money well spent

Thanks. I think every problem is individual and it’s good to investigate thoroughly before throwing blanket Solutions out. The thing I will say is that, if you have to vacate your property often to keep it dryer then there must be a problem? I know houses where I can stay all day every day. Absolutely no problem in fact quite the opposite very dry. The Sun is hitting the property all day long on one side or the other. My property? No chance sun does not hit it, especially in the winter and in the summer not all day front and back. Get some sun in the morning and evening. This results in ridiculous condensation damp, mould everywhere. There has to be built in Solutions. I feel like I understand this very well now. PIV is a must? Another ventilation system in the house as well? There are some people who cannot vacate the property. They are housebound elderly and disabled as an example, but I don’t understand if you have to vacate the property regularly. Then in my opinion it’s not fit for a living why even build something like that, and if you do build that, then you should build in there filtration, ventilation, whatever is needed.

The controversial issue of rising damp is resolved for me when I look at the brick bridge over the Towy River in Carmarthen, the sides of which descend into the water. If rising damp existed, surely damp bricks and moisture would be visible above the water level? However, on a clear day it's bone dry. I'm dealing with a wet cellar in a Victorian renovation and have researched damp issues extensively. Finally decided to go with ventilation so this video was helpful and interesting. Thanks 👍

Great information gathered there Rodger. Keep up the great work.

We had salts/damp in the chimney, we lifted the tile base and discovered a hole in the base of the chimney floor, it was literally a puddle of water. We’d had the roof done already,and made sure there were no flower beds against it. We fixed the broken floor, relaid the tile, and over time the chimney dried out. Another problem in our kitchen was the neighbours bathroom upstairs, small gap in grout was letting water through. Neighbours eh? 😂

Before people spend money on damp cures they should try a few basic things to reduce damp. I had really bad condensation and damp issues. I had 3 cowboys come round a quote. One told me I needed a PIV, another told me my damp proof course was gone and another told me to replaster the walls. In the end I kept 3 windows on night latch and kept the bathroom door closed and the humidity dropped from over 65% to below 40% in 3 weeks, no more condensation at all and damp is drying out in the walls.....all for free.

400w heater at 33.9129p per kWh. Leave the heater on and it starts at 10 degrees or lower and costs a fortune to run. Is that 30 odd pence per 2 hours? 15p per hour?Easy £3 per day during the winter months. £90 per month. I have a Flatmaster and have the heater turned off and have the thing on a smart plug and I turn it off when the temp drops to very cold. Cheaper to turn the central heating on than run the heater on one of these.

Class video Rodger. Educational. 👍

pivs are awesome

Would be nice if you could show some examples (pictures) to highlight the different scenarios you are talking about.

Always start from the top going down. Roof, chimney. Flashing. Guttering. Walls not pointed. For 5 years i had roofers round. Never solved my issue. I Was told condensation. Chimney and bad render was causing issues. Finally removed the chimney and looking good. Water travels a long way. Mine went vertical for a 4/5 metres.

Love watching Rodger! I have a bit of rising damp or a rain leak downstairs. I also have one bedroom corner that gets super mouldy after raining and gets mould very quick so I must have a rain leak there! Im getting a buildings and damp survey in 2 weeks.

Dehumidifiers still noisy and power hungry but it did the job, but my loft Nuaire PIV is working awesome, the heater element uses a lot of power not as much as the dehumidifier, since installing the the PIV my humidity has gone from 70% to 40/38% sometimes mainly stays at 40 and downstairs can drop to 35%, radiator on the landing keeps that area from getting too cold which has allowed me to decommission the heater element. The dehumidifier Meaco 25L used 53kWh an hour running almost 24/7 as that was the only way it would keep the humidity levels down but as soon as it stopped humidity started to rise so it switched back on. Compare the dehumidifier to the PIV, the PIV has got the humidity down to a level that surpassed the dehumidifier and it only uses 5.1kWh without the heater. This makes the PIV not even register in my mind for sucking the jungle juice from the wall, where I was looking at the dehumidifier on the landing knowing it was doing it’s job but still cursing it with how much it would cost me with all the jungle juice that it was using. PS do your home work on PIV’s I went with Vent-Axia because I could get an F7 filter, that filters out diesel particulates. Carbon filters are better than F5 or F7 but too expensive in any brand of PIV and also have a short life span compared to a F cotton filter

Love the great explanations.

Great video guys! Really like these! Will research these PIV units. They sound excellent.

Very impressed by how knowledgeable the guest is, however, Positive Input Ventilation has lost favour since this video was posted 3 years ago. This is because of the risk of interstitial condensation, especially in the context of increased insulation for retrofit work. For this reason, most retrofit organizations will advise against PIV.

+1 For the Nuaire drimaster PIV system, I don’t have the heater model and personally don’t mind as we only have to run ours on level 1 or 2 and any cold air from the attic is warmed up by the central heating being on. It’s solved our condensation issue, we leave our bedroom doors cracked open at night and we have zero condensation on any window thanks to the PIV system.

Seems like a 400W fan could be quite costly these days, although I'm guessing it won't be running at that 24/7.

i use the dryrods. they are brilliant

We have some similar types of older buildings in Australia but not too many, thank God with the same issues. What I find interesting is that in the UK, you don't seem to have central heating. In colder climate areas we use a lot of ducted central heating. It's brilliant. Gas powered and just amazing. You don't even know it's on and the whole house is toasty.

I get a lot of water on windows in the morning what can I do to get rid of it thanks your doing a great job and your very informative

He touched on surveyor's in my only experience i found them to be a massive Waste of money.I would tell anyone buying a house to get the most basic survey possible and pay a good multi trade builder to spend half an hour looking over the house and advising you on any issues.

Super informative! thanks for this

Nice chat, a bit long for my liking but I couldn't stop till the end. Damp doesn't concern me, I have a MVHR, but I really liked the chat. Keep em coming. Good luck!

I'm a glazing service engineer and regularly get called out to conservatorys with customers complaining about condensation, yet on arrival there is two heaters going drying clothes in there 🤦‍♂️. They look baffled when I say what the problem is.

Can anyone explain to me where the idea of sealed houses came from. Is it EU rules. As a decorator, over the years can you imagine the amount of properties I've seen and been questioned about the presence of mould. Open a a f##king window. Sorry for being controversial.

I really enjoyed this video until you got to the part about drilling and injecting. In 26 years of diagnosing damp issues I have never yet recommended doing that even to older buildings. In my opinion, if you have rising or penetrating damp, find the cause and fix it rather than just drilling and injecting

Might be worth describing the various types of survey available.

Very interesting chaps thanks very much 👌🏼🧱👍🏼

A roof needs to breath or you will get moisture/condensation which will rot joists eventually, also dehumidifiers will attract moisture from the rest of the house into the room it’s being used in, yes agree no chimneys more condensation especially in new houses, pets and fish tanks also create a lot of condensation issues. Heat and ventilation are the cure, PIV’s do work. This is mainly a life style issue and people need to be educated on this rather than seal there property air tight.

Interesting video, well done.

In my old house, we had the chimney capped as we were sick of the sound of the wind blowing down it. Especially to the fireplace in our bedroom. Once we did that, we started to suffer really badly with condensation. In hindsight I would have rather put up with the noise when it was windy.

I love the damp!