Salt/cristaline wall secretions... how to paint/handle this?

[queequeg152]

Why do u need the paint to be breathable? To suck more moisture inside to then dry it w either normal air circ or a deuy? Why?

If u clean all the buildup thoroughly, then seal the inside walls w moisture resistant primer/top coat, that should end ur problem. No more water coming through the wall, less humidity, no salt build up. Peeps that put in a livining area in a damp basement seal the walls this way all the time, then just frame and drywall.

U wont be digging out 2-3' all the way around your foundation from the outside and then do a proper sealing anyway, so sealing the inside wall is the next best thing. I think u r overthinking it.

Id seal it w a good primer like the kilz, or something like it. Maybe even look into a marine paint/primer, assuming it will bond well w cement. Ez as painting and venting... And prepping the wall before.

why do people think kilz is the end all of good primers? in my experiance, pretty much all of the 'do it all' paints and primers are not great on any substrate. just ok.

regarding paints. its generally thought that the concrete walls should be able to dry to the interior slowly via vapor retarding assemblies or coatings...
however people spray closed cell foams on basment walls ALL THE TIME...from what i know this has never been a problem.
closed cell foams are about as vapor tight as you an get.
so i agree with your that you COULD use a vapor tight coating of some sort, but only if the basement does not have water flooding issues. its just not an industry accepted practice.

the amount of moisture you would exclude though is less than you think... moving to a low from a high perm paint.


but if you have flooding issues you will still need a system to handle that water. no coating short of like... polyurea or something very hearty will stop water from getting into a basement.

 

[bigbadbiddy]

No flooding issues.

The salt secretions are completely benign and don't come back as fast as I feared after removal. Just steady.

There was heavy rain recently and no visible signs of it in the basement.


I wanted to paint it breathable because I don't want to lock in any moisture into the wall. On the other side there is just moist/humid earth and if I seal the inside wall, I am confident the moisture will be trapped in the wall. Over years, I would surmise that the wall's integrity/stability will suffer immensely.


That's why I will go with that special "breathable" caulk/mortar and hang panda film on top.
Afaik panda film is not a big fire hazard at all.

My biggest concern will be checking behind the panda film regularly to make sure I didn't speed along the development of anything else covering the wall with panda film.

 

[queequeg152]

No flooding issues.

The salt secretions are completely benign and don't come back as fast as I feared after removal. Just steady.

There was heavy rain recently and no visible signs of it in the basement.


I wanted to paint it breathable because I don't want to lock in any moisture into the wall. On the other side there is just moist/humid earth and if I seal the inside wall, I am confident the moisture will be trapped in the wall. Over years, I would surmise that the wall's integrity/stability will suffer immensely.


That's why I will go with that special "breathable" caulk/mortar and hang panda film on top.
Afaik panda film is not a big fire hazard at all.

My biggest concern will be checking behind the panda film regularly to make sure I didn't speed along the development of anything else covering the wall with panda film.

concrete will happily stay damp 247 so long as its cured properly in the first place.

its the steel inside the wall that does not appreciate being wet 247. still though the foundation(assuming no soil issues) will last a very long time, longer than the joists... beams spanning the basement etc. moisture not withstanding.

again though, the diifference in terms of condensable moisture between a low perm paint and a high perm paint is less than you might think. were talking like a quart of water less per day max.

high perm stuff like the WRB wraps ... tyvek etc are there so that moisture trapped inside walls can escape, albeit at a slow rate.
even moisture escaping at a slow rate will prevent extensive damage though.

 

[stoned-trout]

the foundation needs to be seal coated on the outside...I used to do it for a living ...its messy...then the inside wont be a problem anymore...yeehaw

 

[bigbadbiddy]

Well yes, the ideal course of action is clear.

But it would be a major investment and set me back months if I were to re-seal the foundation from the outside.

I am talking 10k easily around here and probably 2 months at least that I would live on a construction site, again...

But I have spoken with neighbors, read into the topic more etc. and found out that most basements are like this in the area and have been for decades, some for a century or more.

Nobody ever had any issues with it and they all just live with it since it is benign. Those houses also have been standing for, like I said, up to a century in some cases.

I just don't want to "make it worse" in any way by sealing the wall from the inside. Because that is something nobody in the neighborhood has done afaik.

Will keep you guys posted and might get this thread out again in a year or so if I ran into any issues.

For now I believe it will be fine if I go for the less costly and less ideal option of treating the wall from the inside with the special caulk/mortar and using panda film instead of painting to make sure I don't seal anything inside the walls.


Down the road I may cough up the dinero for the ideal solution but right now that would set me back too much.

 

[bigbadbiddy]

Hi there folks,

I'm back because... well something happened to that wall

I covered the wall with the special "breathable" mortar/caulk that is used around these woods for situations like this.

Unfortunately the "white fuzz" aka crystalline secretions have since become full-blown mold.

Before I covered the wall in the special mortar/caulk, it felt wet but the "white fuzz" was the only visible thing and when touched, it felt dry and crumbled.

After having applied the special mortar/caulk, soon actual black spots started to appear.
It is mold without a doubt, smells like it when you touch it/scrape it off.

A friend suggested that the mold was simply not visible before we applied the special mortar/caulk but then why couldn't I smell it when I scraped off the "white fuzz" before?

I am a bit unsure what to do now...

Scrape off the special mortar/caulk again and hang panda film on top?
Leave it as it is and just hang panda film over the whole mess (then check behind the panda film after half a year or so?)?

I'm a bit sad and angry. It seems like I just should have left the wall be and hung panda film over it, now it seems like I made things worse by treating it with that breathable mortar/caulk...

 

[queequeg152]

you have mold growing ontop of your vapor tight coating? how is that possiible. mold needs moisture to thrive?

 

[bigbadbiddy]

The coating is not vapor-tight, actually the opposite.

I didn't want to "seal in" the wetness after talking with people who deal with these kinds of issues around here.

They suggested to me (and I agreed) that using this special caulk/mortar that is "breathable" and allows the wetness "to escape" would be the way to move forward.

The coating is basically very "fluffy" when you apply it and is supposed to allow the wetness to seep through i.e. aid in "pulling it out" of the wall instead of sealing it inside.

My assumption is that there either was mold just inside the wall but it didn't take hold on the wall itself (only the white fuzz or crystalline secretions did).
Now with the special caulk/mortar coating applied, the mold apparently has a place to "root" and grow ...
Or there was no mold to begin with and it just appeared now because of the additional coating...

I will scrape off the mold today and treat the wall with chlorine, hoping that will do something.

Unless someone has another suggestion ...

I will then hang panda film on top after it dried and make a run, checking behind the panda film after that run to see what happened.

My hope is that with the ventilation and heat from the lamps, the mold will be combated...

If things go completely wrong, I will likely have to swap my veg and bloom chamber which would suck because I would loose an easy 20-30 cm of headspace for the plants T_T

 

[queequeg152]

i have 0 clue what coating you are talking about.

can you link me something?

its entiierly possible the coating is simply holding too much moisture... and or, the coating is itself nutritious in some way.

mold needs 2 things, lots of moisture and nutrients. cut off one and you can stop the mold spreading.

 

[bigbadbiddy]

Heyo,

thanks for staying interested and being willing to help me quee, much appreciated!

I found this youtub vid, hope it's ok to link it:
https://www.youtube.com/watch?v=x8MzujrITUg

At the start there is some explanation on the concept of the stuff and at around 2:30 the guy starts mixing it up and applying it to the wall.

I doubt the coating is nutritious in itself but due to its "fluffyness" it might offer a better surface for the mold to take hold, absorb nutes and be supplied with moisture than it had previously with "just the wall".


The "proper" way to use this special coating is to use it as a last step after drying the wall from the outside and fixing the insulation.
It is normally used as a last step to help extract all remaining moisture and salts from the wall before ultimately applying another insulating coat from the inside to seal it off completely. At least that was my understanding.

My expectation was that it would just help extracting the moisture, making sure it does not get trapped in the wall and causing further damage in the future...

 

[queequeg152]

wow wtf are you guys doing over there in the UK?

seriously this dude is flinging the scratch coat on the wall? what the hell?

ANYWAY.

you are talking about this stuff?

http://www.kosterusa.com/us_en/prodid-95-1899/restoration+plaster+2+white.html

i can see why you would call it fluffy... 41% pososity!

heres where i get confused. 2 things.

1. plaster usually does not promote mold growth. its just lime and portland and maby some crushed marble and shit.

2. this stuff is light and fluffy and should dry to the interior very well. in other words it should stay very dry because there is so much surface area exposed.


is it possible you installed this stuff incorrectly?

what is the humidity in the basement? are you maby not removing the air evaporated off the wall?

does the wall feel damp? is there any condensation etc?

without putting a membrane on the other side of the foundation wall, there a good chance this will actually increase the amount of moisture you are pulling across this wall. thats not necessarily bad... but you have to give the moisture some path out of the basement.

 

[Granger2]

I would remove as much as possible. Then I'd get a high capacity [for room size] dehumidifier, and run it for the whole room. Build your veg/flower rooms so that they are 3-6" out from the basement walls, putting your reflective film or white painted panels on the inside. I'd, for good measure, put small fans to blow between basement walls and flower/veg room walls. Good luck. -granger

 

[bigbadbiddy]

Thanks guys.

Yep that's the stuff quee.

The idea was indeed to simply pull out more moisture and let it escape.

The ventilation is not completely installed yet and only the veg chamber is running so I think air gets a bit trapped in there still and I hope when I finished installing all the ventilation the problem will resolve itself.

I have a large dehumidifier on standby and will install it soon to see how it will impact the whole situation.

It is theoretically possible that the stuff was applied incorrectly but I did let a "professional" do that before I started installing stuff in the room. Can't really invite him back though and ask him if he messed up as stuff is already growing there


The wall feels damp in the same spots it was damp before the coat was applied (which are also the spots where the mold is growing).

Lack of air removal could definitely be a possible problem and will be resolved shortly.

Humidity was around 45% last time I checked.


I treated the wall with chlorine yesterday, gonna have a look at it today and move forward with my installations.
If the mold is already coming back today/tomorrow, I will run the dehumidifier.

Once I installed everything, I will make 1 run and look behind the panda film to see if the mold is back after ventilation is pulling out air properly, the dehumidifer had a chance to do its work and the temps are up from the lights.

Maybe these 3 factors will already deal with the issue.

Fingers crossed.

And thanks for your feedback and help guys, much appreciated!

 

[queequeg152]

bleach needs scrubbing to remove mold. even then it will come back untill you resolve the moisture issue.

there are special solutions you can buy to treat mildew in flood damaged houses... again though, treated areas are NOT like pressure treated lumber or what ever... the mold spores are always around. they are aways ready to sporulate again provided the moisture and food is there to support its growth.

with that said though... 45%. is insanely low for a basement.

as an engineer i would LOVE to see you test wall assembly for moisture and vapor...
but this costs money. not a huge amount... but probably like 70 bucks for both.

have you ever heard of a
karsten tube?

have you ever heard of the concrete moisture test?

or the better concrete desicant test?

if you ever have to sue a contractor for a shitty concrete job this is one of the tests they might perform. they are good tests... not super insanely expensive, but not super cheap either.

before you remove any material... personally i would like to see you perform them.

if you do only one, i would say do the desicant moisture test, but a karsten tube is only like 20 bucks. my gut tells me that they would be available everywhere in the UK seeing as to how many old buildings you folks have... and how much masonry you folks seem to use in housing.

ive never done one one of these tests personally, but i would be glad to hell you pull down the ASCE standards or what ever standards govern the test.

what these tests will tell you is exactly how much moisture is escaping from the wall, and how moisture permeable your wall is.

its entirely possible that this issue is deeper than it seems.
i keep going back to the fact that plaster is NORMALLY very mold resistant. again its almost the same as mortar or concrete sans the aggregate.

however this plaster being very porous... perhaps it has some cellulose or something wierd inside it that mold can eat up?

perhaps this stuff can be treated in such a way to make that cellulose unavailable... a siloxane sealer comes to mind, but you might also be able to spray something like a acrylic sealer too.

siloxane sealers are VERY expensive btw. they dont last forever either.

it should be a last resort... were talking like 100 bucks a gallon in some cases. alot of people rush into brick sealers because they dont want to hire masons to actually fix the water ingress issue due to bad flashing and lack of capillary etc... but an actual mason doing actual work in some cases might actually be a cheaper option, and an option that does not discolor the brick AND an option that lasts.

 

[bigbadbiddy]

*sigh* I just typed out a long ass answer and my browser crashed

Anyway:
Thanks man, great feedback and advice!

I checked on the wall yesterday after treating it with chlorine the day before and all the mold was gone, washed off by the chlorine.

The wall is still moist to the touch and moisture is clearly visible in the spots where the mold grew before.

I scrubbed it with a rough sponge and to my surprise there was not even a faint smell or hint of mold. I would have assumed that scrubbing off the top layer would result in some residual spores being released but to my delight there was nothing.

Now I am aware that this is likely only a temporary solution but the way I see it I have 2 options:
1) hang the panda film on top now, make a run and see how additional heat from the lamps and improved air flow from the ventilation setup completed impact the whole situation, then take it from there.
2) do one of the tests you prescribed, realize my wall holds way too much moisture and plunge into counter-measures (laying the wall dry from inside and out, re-sealing it from both sides, etc.).

I will go with option 1) for 2 major reasons.
First off I really wanna have at least 1 run after setting up all of this. Tearing it all down now and delaying for another couple of months would break my heart xD
Secondly I would have to somehow explain to contractors why I have 4 wooden chambers in my basement and all this ventilation work etc. ...
Or I would have to tear down that stuff as well...

Not too keen on any of that plus I would have to find a way to finance all of it first of all.

I think doing one run now and looking at what the situation is afterwards (plus I have the dehumidifier as an ace in the hole) will be best as I will be sure by then if serious action needs to be taken or if I can work with a hotfix for a while.

Would be nice if I could run things as is for a few years before having to tear stuff down and getting construction workers in...


Oh and I forgot to mention:
According to all parties I consulted, it is not advisable to put anything on top of the "fluffy" coating. Neither paint nor sealant, nothing.
If I would go that rout, I should first tear down the layer of special coating before proceeding.

 

[queequeg152]

if you wall is as wet as it seems, you should absolutly NOT put a poly film over it.

that moisture HAS to go somewhere. if you put a film over it you are going to intensify the mold issue 10 fold.

now... you could build a poly film barrier so to speak.... and put in a dehumidifer behind this barrier. but whats the point of that when you could just run a dehuy for the whole space in the first place.

so much of this does not make sense to me at all.

a. you have low ambient humidity... presumably you have 100's of square feet of wall area that is damp to saturated with moisture. how is that possible?

b. you said you never ever had moisture issues prior to this coating.

c. how is mold growing on "plaster" so easily and so quickly? is it collecting dust and the mold are feeding on the dust? or is this special plaster some how nutritious.

its almost like this plaster is acting like a capillary mat of some sort... perhaps at some point the excess moisture will be drawn out of the wall assembly and you will be left with the plaster being dryer... but idk.

again let me reiterate!

the moisture HAS TO GO SOMEWHERE.

this is what happens when you trap moisture behind a polyfilm.

this moisture has to dry to the interior or exterior. you do not have the means to allow it to dry to the exterior, so dry it to the interior.

put in some fans. aim some of them at the wall, and install a beast dehuy. monitor the wall for mold and monitor your condensate volumes.

imo you should get a dehuy + condensate pump... pump the condensate into a closed drum or something that will allow you to monitor the total volume of water collected per day before draining it.

 

[bigbadbiddy]

Hey mate,

I think some of the confusion also comes from me not properly expressing myself, being a noob in all this and not exactly knowing what I am talking about.
Just learning along the ride and understanding better

What I can say is this:
- I checked the humidity again and it is more around the 55% RH range. I misremembered plain and simple ;p It should also be noted that it has been quite dry this year, I assume that it will go up to 65% in certain times.
- Since the chlorine treatment about a week ago, there has been no mold grown back, the wall is still free of mold, just wet to the touch (in certain spots, not everywhere) as usual

I believe the coating works as a capillary mat of some sort indeed and that is exactly what the contractors I employed and myself were hoping for: That the coating will pull out moisture and help it evaporate until at some point the wall might become a bit dryer overall.
That point might already be reached as the mold is currently not growing back so it might actually be working already.

I agree that I should not hang polyfilm on top tightly.
I have a wooden "plank" at the ceiling and floor level. I wanted to attach the pandafilm onto those planks and thus be about 5 cm or so removed from the wall, leaving some breathing room. I would also only staple the pandafilm to those planks and leave the side open, so air can move freely and vapor can escape.
But maybe I just leave the wall free then. Might be some PAR lost or whatever but better than having mold and without panda film on top, I am pretty sure the light+heat from the lamps and the air exchange (the filter and fan are positioned directly in front of the wet wall) will help the wall in dealing with the moisture.


Oh and to correct:
The basement ALWAYS had moisture issues.
Just the issues manifested in the white fuzz/crystalline secretions from the walls and nothing more.
Since I applied the plaster to the one wall, I had that mold bloom on that one particular wall.
There were never mold issues anywhere else in the basement, only crystalline secretions.



Hope I could clarify some stuff and I think I understood some things better as well.


Maybe you could let me know if you think hanging the panda film over the wet wall with some distance (about 5cm) would be alright or if I should just leave it off altogether.

I think at this point i just leave it off altogether and see how the wall reacts for now. Can still hang it later on if I notice no mold coming back and the wall maybe drying off a bit.

If things go array I will employ the heavy duty dehuy (which I reserve as a last resort cause that thing uses way too much electricity).

Thanks so much for keeping an interest!

 

[queequeg152]

im against polyfilms for alot of reasons man... fire being the biggest one.

alot of jobsites burn in part due to people storing shit like solvents and poly films, and or poly films being erected for dust protection and painting etc.

when a fire starts on a job site, 99% of the time people put it out in no time... its that 1% of the time where the fire runs away, and the fumes and smoke due to shit like solvents and plastics make putting it out impossible.

hell i almost started a fire yesterday using a dullish ocillating blade at not very high rpms.

imho in all things you should minimizing the amount of shit that spreads fire and toxic smoke in buildings. yes i understand EVERYTHING generates smoke... all furniture, all matresses, all paints, all shelving etc... but i still like to avoid shit when i can.

all the above being said... your average 1970's carpet underlay is 100x worse than any amount of poly film you could possibly erect... so i guess its important to keep things in perspective.

far as panda film( i assume this is just LDPE polyfilm w/ strong white color?) reflecting light? .... yea IDK to be honest. i would think that the cost of the film is more than the light you gain?

then again are you running bare bulbs?

if you have it on good authority that panda film makes a huge difference verses the white plaster i guess id say go for it? but my gut tells me its negligible.

no i dont think you will have any problems running panda film with a gap as u suggested... i would just pull it back and check the wall for moisture from time to time.

keep me updated on this wall issue if you dont mind...

imo you should run a fan down there 24/7 even if you are not growing shit yet... the faster you can dry that moisture the better.

you also might consider buying a good hydrometer id you dont have one already.
the little digital ones you get for 10 bucks are trash. im speaking from experiance here. yes you can calibrate them to 1 point, but they loose their linearity.

if you can afford it get a synethetic or natural hair hygrometer.

https://www.amazon.com/Ambient-Weat...1_3?ie=UTF8&psc=1&refRID=5DBFB51ZK45F2YA18E9W

try to get something like that. unfortunatly they are sold out now =(. untill recently they were selling for 39 bucks which is a stupid good deal. they are usually like 50-60 bucks on all the weather watching websites.

 

[Granger2]

BBB,
Just bite the bullet and run your dehumidifier 24/7. They don't use that much juice. It will only run when needed. You have in your possession the solution to your problem. Use it. Also, Panda film has very little, if any, advantage over white paint or plaster. We're talking less than 5% and that's only of the reflective light. Good luck. -granger

 

[bigbadbiddy]

Aight guys, I will keep the wet wall free of panda film and just run with it.

I run a 630w CMH in that chamber with bare bulbs.
Probably going to do a run or two with the panda film and then just paint the chamber, excluding the wet wall.

The dehuy I turn on as soon as I feel the wall is no longer getting dryer.
At the moment it seems to be indeed drying off as no mold has come back and I might be imagining it but it seems to me that the wet spots are getting smaller.
Could be due to the recent dry weather though, hasn't been much rain as of late.

I will keep you guys updated but my best guess is that I will have to run the dehuy throughout fall/winter/spring and probably won't need it during the summer. Unless we again get a summer with so much rain.

Will see and keep it monitored and update you guys on time.


Oh and yes, I need to get me a proper hygrometer. I have 3 of those cheap 10 to 20 bucks range ones and they are all showing values differing by up to 5% which is no good. Gonna get me a good one asap.