Rising damp - of course not!
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- Опубликовано: 16 ноя 2024
- This house was 'diagnosed ' by the timber and damp companies as needing £30,000 worth of 'damp' treatment. In fact it needed little or nothing - dry as a bone, but suffering from condensation and high ground levels. It needs very little expense - just sensible restoration. Here's a few pointers on how to avoid being defrauded by damp companies.. See www.heritage-ho... for more details.
Very, very interesting. Thanks so much for taking the time to make this video - really appreciated!
Really interesting videos thank you for uploading all this information. Its all so obvious really now you point out. These houses were built as is and designed the correct way. Its not the house that is at fault causing the damp is it ?... Its all down to years and years of re decoration, re skiming , re pointing using wrong materials. As you point out all restoration and repairs should be carried out like for like. You have inspired me to go deeper into this subject as I do a lot of renovation work. Thanks and keep up the good work.
Thanks Peter - it's rarely if ever the house - and almost always what people have done later with modern materials which trap moisture. Ventilate, ventilate - and that does prevent problems, but doesn't remove the issue that these modern materials will trap moisture. If you need help, shout - or watch www.heritage-house.org for more.... :-)
Peter Ward Thank you I will take a look at that.
Might not be rising damp but it has been wet. Condensation is a nightmare in any building. I have seen many problems caused by double glazing too. I have an old stone farmhouse with Victorian cement render and dash on the outside but all lime inside. It seems to work just fine. House was built in 1899.
Peter, I survey houses for a living and find your criticism of the use of electric prong surface measuring damp meters and how the use of cement render can exacerbate problems very interesting.
Three questions if I may: 1 ) where you got low relative humidity but with salts to the walls in this house what did the speedy meter reading show? 2) why was there so much condensation - no heating and poor insulation ? 3) The salts will deteriorate any decoration applied in the future, what remedial work is recommended to deal with the salts and make the wall ready to receive decoration.
Regards Jon Winn MRICS
Jonathan Winn Hi! Answers: 1. Speedy was zero. Salts were surface concentrated - probably from minor deterioration of lime plaster over the years, and entrapment behind the wallpaper. Very little salts to be fair - more conductive - probably wallpaper glues etc... 2) Condensation was mainly because of the heating regime - on for 2 hrs in am, off, and on for 3 hrs at night - walls never warm up, moisture loads into air, temps drop at night, condenses out. High humidity because of the water leak under founds, and water getting into sub floor through vents. I suspect with better venting, humidity will drop under floors, thus less supply of moist air, and therefore less condensation. I'll monitor the house as they work on it. Insulation was ok - some window glazing had gone, so losing heat - loft insulated ok. 3) In this place, very few salts - if on lime plaster, I wash down, clean off, and use breathable paints - proper ones - Earthborn clay paints.. Salts will come through and crystallise out and drop off, without pushing paint off wall, so gradually dissipate. They are only really a problem if you trap them and allow build up.. Cheers!
Pete
Peter thanks, most interesting. Do you think a Protimeter survey master on search mode would have given a high reading in this scenario? Jon
Great explanation Peter.. This will help me solve my damp patch
a honest man with a honest straight forward answer.....now if the damp man mr wally came he be drilling holes everywhere lol
this is eye opening for me I work as a handyman , i have been telling clients ventalition is very helpful ,, but it looks like wall paper and glue could be a big problem and loads of other reasons cause damp like conditions , but to take rising damp off the list is a big help ,,under a clients instruction, i did loads of removing plaster applying what i thought was a water proofing /anti damp course, it was all probably a waste of time i know one room failed , they then called a injection company , again a waste of time ??
yup! Focus on ventilation and dry air - constant low temp heating - RH 50 to 55% at about 15 to 18 degrees C. Cant really get cold or damp (condensation) walls then... Pete
Peter Ward
I find your videos & explanations a real help & have hopefully solved a major problem for me. Having had 3 different tradesmen around to look at my problem ive been advised to 1) have a damp course fitted; 2) have the walls injected & 3) strip the walls to the brick & tank them !
However, following your advice, once I hack off the several layers plaster & expose the brick letting the walls breathe & dry out, what materials do I use to decorate them, eg. plan was to have them skimmed & painted. Any advice would be extremely welcome.
Apologies - only just seen this!! Hack off but keep breathable - ideally use lime palster - and breathable paints - earthborn clay paints are good.. Dont skim - it'll come off again. Monitor humidity in house - 50 to 55% max - ground levels outside 150mm below internal floors, check all drains not cracked or leaking / broken etc...
My buildings problem is mostly on the North end, and noticed either salt or lime drawing from the brickwork externally, internally wall paper comes away but plasterer appears dry. Since installing double glazing and keeping the temp16-18c during winter , noticeable improvement. I don't know if the property needs more ventilation although near one of the problem areas, where the floor timbers are slightly damp, there is a boxed in pip to the upstairs flat (water supply I think) would the copper draw moisture to that area? ( assuming it's copper pipes).
could do - see other reply - bung pics and ifo to us - office@heritage-consulting.org
Thanks Peter, I love how damp proof pain adverts come up! :)
Yup - every time we show an advert we get a few pennies - so we're costing the manufacturers money all the time - serves them right!
Hi Peter, great video - very informative! I have just had a survey done on a property i intend to purchase and it's come back requesting a timber and damp report. Is this something you could do or could you recommend someone? The house is in Bridgend, South Wales... Thanks Mike
Gawd - the usual incompetent valuation surveyors covering their arse. We can certainly do - getting close to xmas though - we are very busy and trying to finish loads of stuff before.. If the survey is asking for timber and damp, bin the survey - not worth the paper written on. If you send full details to office@heritage-consulting.org we'll see what we can do.. Pete
a friend has been told they have rubble .mortar bridging their damp course dmp 1990s house .they have had a endoscope put into cavity and say its causing damp to form at base of wall and rise up
Like the videos Peter. If the damp is simply due to condensation, where are the salts coming from? Non-volatile compounds like salt will not be present in water vapour, so I'm wondering where they come from if not through the bricks?
All building materials have salts - bricks are fired - clay burns = salts. Brick gets damp, salts move with moisture to outer surface, water evaporates, salts left behind. Add more salts from any acidic reaction of water - rainwater is slightly acid, walls often got nitrates from traffic fumes - salts can build up quite quickly really..
By salt do you mean efflorescence
the salts came from the rising damp transporting them up the bricks?
lol i bet you watch loads and loads of star trek too huh? great comment lol
jesus shaves
Hey person, thanks for the intelligent comment.
Well actually, we moved into a house years ago that had fictitious rising damp, the clothes got fictitious mildew and the place fictitiously stank but this is of course the imagination of the family and visitors since it (rising damp) doesn't exist.
By preventing the fictitious rising damp from occurring (by sealing the bottom row of bricks with pump in sealer) the strangest thing happened, after several months no more mildew and no more smell and no more paint peeling off the walls.
I say "strange" as after all, according to some comedians on television, rising damp does not exist.
or
does it?
(ominous music in the background)
en.wikipedia.org/wiki/Damp_(structural)#Rising_damp_-_Historical_evidence
Skepticism
Rising damp is a phenomenon that is fully predicted by the laws of physics,[22] has been researched on a worldwide scale,[13] and has been documented since Roman times.[14][15] Nevertheless a small number of people have expressed the view that rising damp is a myth and that it is, in fact, impossible for moisture to rise from the ground into the wall structure through pores in the masonry. A former chairman of the construction arm of the Royal Institution of Chartered Surveyors (RICS), Stephen Boniface, has said that 'true rising damp' is a myth and chemically injected damp-proof courses (DPC) are 'a complete waste of money'.[23] However he has recently clarified this statement on a comment post made on the Surveying Property website, "Whilst I have often been quoted as stating "rising damp is a myth" the only time I have ever said that phrase (or similar) is once when delivering a paper at a conference and then using the intake of breath as a cue to then develop the argument further and explore the issue of damp. In other words I used the phrase provocatively (it usually worked). I then went on to state that whilst I accept rising damp (as a term often used by the public and professionals alike) might exist it is indeed extremely rare. I have at other times referred to the myth of rising dampness and explained what I understand without actually stating myself that it is a complete myth."[24]
GREAT PRESENTATION PETER, AND ANSWERS A LOT OF MY DAMP PROBLEMS, OR WHAT I ASSUMED TO BE DAMP. JUST A QUICK QUESTION REGARDING THIS VIDEO, AFTER BRUSHING OF LAST REMAINING SALTS OFF THE AFFECTED AREA, WHAT MATERIALS , IE WALL PAPER PAINTS SHOULD YOU USE TO TIDY/MAKE GOOD?
Not wallpaper, use earthborn clay paints ideally - breathable, and lovely to work with. Salts not easy to get rid of - might need to get rid of badly salted plaster - but need to know more really... If got more info, can send to us at office@heritage-consulting.org and we can try to help... Pete
Hi Peter, i've been watching your videos with great interest. I live in an old house, brick walls with lime mortar and i am looking to make one of my walls water proof, because it gets exposed a lot to harsh weather and a very wet environment (rain accumulates at the bottom, dries very slow). What solutions do you recommend for water proofing that wall, because my constructor wants me to pun on a water repellent cement based mortar at the base of the wall but i know it won't work well with the lime mortar in between the bricks.
thank you!
Dont use water repellents - limewash will help a lot - build up coats of it... French drains, reduce ground levels, need to know more really before can help - difficult with just a few words and no idea of the actual situation.. could send pics to office@heritage-consulting.org and we'll try to help..
my understanding is moisture allows the salts to transfer through from ground moisture due to a failing damp course, is that not true?
Not true.. damp courses don't fail. Salts aren't in the ground anyway. Most moisture is there from condensation within the wall - looks like rising because at bottom - but lower part of wall is coolest, and you need to look inside house - what moisture levels - RH and temps - kitchen well ventilated, bathrooms etc? These are the main causes, together with bad drains - cracks, blocked, damp ground outside house - ground levels too high etc...
Peter Ward,
If the dampness was caused only by condensation, why does it occur only at the bottom of the walls, and not also near the top of the walls or around mid-height of the walls?
Kob Mohan Gravity? Cold air nearer the ground = higher humidity
***** Also colder building fabric near the ground.
I had terrible condensation in my house which i fixed with the drimaster 2000 unit worked a treat. However i have tide marks on some of my internal walls and bits collecting around the skirting. Does abybody know if this Is this salt in the plaster? How do i cure it?
Sounds like still have interstitial condensation. Would need to know more - photos etc.. there may well be salt in plaster, and if house is now dry, moisture may be coming out of walls, bringing salt with it....
What is your opinion on PIV unit for old design houses with high condensation and poor ventilation?
I'm not that happy with them. A lot of problems because they are not monitoring humidity. You are far better sorting out good ventilation - opening fireplaces, chimneys, etc - and extracting kitchen, bathrooms properly. Diagnose WHY there is condensation first instead of rushing into piv which tackles the symptom. Where is the moisture from? have you got blocked vents under floors for eg? Badly vented roof.. If all else fails, contact Ray Hudson at RHL Limited - who is one of the most experienced people in this game - and will sort out humidity controlled ventilation that will certainly cure condensation - but in a way that moves dry air into the right places, rather than blindly sucking air in, which may well be damper than where it is going!
Would positive air ventilation make any difference here?
+Kyle Rogers Might - I hesitate though - find the REAL cause of moisture - humidity - first - the PIV system just removes the symptom - bit like damp proofing - you need to find WHY there is high humdity - needs to be below 5%% at about 15 or 17 degrees C, If too humid - go looking for the cuase - no vents in kitchen, bathroom, blocked underfloor vents, blocked drains and so on - diagnose the issues, and you wont need piv.
+Peter Ward that makes sense Yeh. I fix damp for a living and honestly, the way I've been trained is everything you hate :-P
+Kyle Rogers Well - always time to make a change, and do it right - lots of happy customers. We help loads of folk in your position - some damppeople just don't know anything better because, as youo say, its how they were trained. You have opened your mind to other ways - that's great - just keep looking and learning - it's a good place to be, because you realise chemicals don't have a place any more - holistic approach is best - just not for the pca!
Peter Ward h
hi,been watching your videos. love your advice. we've bought a 1947 house and when moved in had damp. filled in the patches with filler for short time and seemed to dry out. then we put decking around that area outside and its come back. is this due to the decking. its 5cm away from the wall. the man who fitted it said it wasn't too close but I'm starting to think it is. we are getting big damp patched and salts coming through. we've put an air brick in and cleaned the wet cavity out. any tips? can plastering with a treatment help or is it just a someone trying to make money...
Just making money - more likely it is high humidity in house - RH of 50 to 55% at 15 to 18 C. If RH too high, humidity causes condensation in wall - and thats pushing plaster and paint off. Decking wont help, but not main cause. Ground levels need to be about 150mm below internal floor level. Pete
Does it mean that in solid wall houses you cannot use wallpapers?
yes and no - need to be breathable - most have plastic facing, so arent.. Old pure paper may be ok - but if humidity in house is low - ie less than 55%RH on average, little chance of condensation affecting walls anyway.
You can't correctly diagnose rising damp measuring the humidity of the wall on the surface, or by surface manifestations alone. Rising damp is dampness in DEPTH, condensation is dampness on the SURFACE due to warm air condensing on cold wall surfaces. In case of rising damp wall is the dampest in depth as at the surface dries somewhat out due to evaporation, heat, sunshine etc. In order to correctly diagnose rising damp you need an instrument what measures the wall's water content in DEPTH or take drilled samples from the core/depth of the wall.
The video does not mention anything about where those lots of salts are coming from, just "they are there". Salts in the wall are coming from the ground, as water is attracted upwards inside the capillaries, then evaporates on the surface and salts will be left behind. Salts expand in volume while solidifying, pushing the wallpaper or plaster away from the wall. The wallpaper also feels damp at touch because of the constant evaporation, water comes in at the bottom then evaporates out higher.
Based on the looks there is rising damp in that building which can be confirmed easily by some additional measurements, and can not be reliably determined by surface measurements alone.
Aquapol Scotland Wrong. Condensation happens right through the wall - ever heard of diffusion? Salts do NOT come out of the ground - they are formed as a result of chemical reactions in the wall between water from diffused gases and mortars, plasters, glues etc - I have never seen rising damp - its a total myth and a con. Sorry. We measure moisture in walls all the time - carbide samples - and have never yet had to put something down to rising - it is ALWAYS condensation / diffusion related and easily fixed without any reference to rising damp treatments. You need to get your chemistry and physics right before making comments like that.
like peter said "rising damp" is a total myth and in holland they don't even use damp courses it just an easy way for some people to fleece someone with all that baloney
Peter Ward another cowboy stopped in he's tracks well done pete i read that web page and it's brilliant thanks mate all the best bud!
Cowboys everywhere! Rising damp doesnt exist - we all know that - neither does capillary rise - testing walls internally is what we do all the time. Salts dont come from the ground - have started writing about salts - try this: I'll add more as I get time... www.heritage-house.org/salt-damage-in-old-buildings.html
Peter Ward brilliant peter thanks and i've just watched that video called "renovation rising damp? not such thing" and towards the end there is a guy called jeff howell who undertook an experiment in which he built columns of bricks that he submersed in water for 3 years and surprise surprise no evidence of "rising damp" what so ever, what more evidence do you need?
why is most of the 'damp problems ' at the base of the walls .
It's temperature related - why we always use imaging cameras in our work to see temperature gradients in walls. Moisture is there because it diffuses through the wall as a gas, together with nitrogen, oxygen - in the air. It only becomes a problem when it condenses as a liquid. That happens when the wall cools down below dew point - you could liken it to fog forming in the wall - and as water condenses the wall gets wet. It dries out if the wall is breathable - lime mortar, soft stone etc - but if covered with cement and gypsum plaster it can't then evaporate and gets trapped. The base of a wall is usually the coldest bit - hence damp being at the base. Nothing to do with capillary action which can't really happen anyway as the pore sizing is too random, and not connected together.
"just brush off the salts once its gone, you've got a dry room" He says
unbelievable
yup... just that - salts are hygroscopic and draw water into wall - get rid, no water. Simples! Have to stop more salts though - often from fireplaces.. so line chimneys.. Have faith - its not rocket science.
nice
I send you private message - please check your inbox?
Dry Room? With bare brickwork? Folk stopped living like cavemen when the dinosaurs died out. Cement render attracting salts resulting in condensation? What are you suggesting? That we kango off all cement render and replace with lime plaster and a lime wash or distemper paint to enable the structure to breathe? Totally impracticable for most people as the skills have died out unfortunately. I'm probably only one of the tradesmen skilled in lime in the area within a 50 mile radius possibly more! Correct salts are coming to the surface of the chimney breast due to the sooty deposits left behind from the burning of solid fuels back in the day resulting in creosote deposits. No work required again I suppose? How about we tank out the salts on the chimney from floor to ceiling level using an air cavity membrane in order to allow the client to decorate the surface without having to reinstate the old coal appliance if they so wish? Are you punting for paid surveys on here Peter?
Yep - simple. And no the skills have not died out - they are more and more commonplace as people realise what mistakes they have been making. Tanking out salts justs leaves the problem to carry on - really need to address the problem first. And yes - we do paid surveys by the hundred all over the country - and get amazing feedback from happy cliewnts who have been saved from spending thousands on ridiculous cures that won't work. We specify, we help improve the internal environment to prevent further issues - we diagnose properly what the problems are. We are leaders in the field, working to BS 7913: 2013 - and very good at what we do. Get yer kango going, get rid of the cement render, and start using lime. You'll get a pleasant surprise if you take the trouble to learn lime plastering and realise what a huge demand there is....:-)