I screwed up my garage, need help

[ratrodder123]

Well, I started this thread in the heating and ac forum but havent gotten any further direction, maybe someone here can help me out. Bear with me.. I have a block wall garage in pennsylvania. I put plastic up on the walls and studed with 2x4's. The 2x4's are not very far off the wall (1/4" at the most). I purchased fiberglass faced insulation and drywall but havent put it up yet. I now know the plastic (vapor barrier) is on the wrong side and after 4 months have mold spots on a couple damp spots on one of the walls.

Now what should I do to correct this. My thoughts were to cut the plastic out and remove it in the stud cavities but leave the remaining plastic behind the studs. Then put 1/4" foam board sheathing thats perforated and breathable (lowes item# 304092) in each stud cavity followed by the rolled fiberglass faced insulation and then drywall. This garage is detatched and it will only be heated when I am using it here and there on the weekends. What do you guys suggest?

 

[srmofo]

cutting the plastic out should be sufficient. Once its mostly gone its no longer a vapor barrier.

I would take extreme prejudice against those mold spores before doing anything to cover it up. Seriously, Im talking heavy bleach/water dilution followed by ample dry time and then several days/weeks before doing anything else......and then bleaching it one last time for good measure

 

[Ron Lombardo]

.... and find out where the water is coming from and correct the issue on the outside causing the mold issue.

R

 

[Scott65]

Not sure if this is the correct answer, but a block paint that seals out moisture would likely do the trick. Concrete will alway allow some moisture through even when not leaking, and the only way to keep the wall dry on the inside is to coat it with something that is impervious to moisture. I have taken this approach one time in the past and it worked well.

 

[Daniel Dudley]

Go for it. Bleach the mold and use JoMax.

 

[RHD 4 LIFE]

A
As said you need to remove the polly on the block side of the studs. Clean the mold with bleach or antibacterial soap! Now you can put the polly up on the inside and then cover with drywall!
This will solve your dilemma!

 

[Ron Lombardo]

If there is moisture penetrating the exterior you can paint and seal it all you want it will always be moist ... suit yourself a dry wall will solve a lot of issues ..especially the block from decaying and breaking down from the water problem ... most times its a simple a a leaking gutter or extending the downspouts away from the house.

The ploy on the inside of the studs will cause the moisture to grow mold onthe studs and insulation ?

 

[ratrodder123]

There is one wall that gets a few 2'x1' moist spots on it this time of year. The wall is completly above ground and exposed to the weather. I think its just normal blead through from it being so wet outside, it only happens in the winter. The garage was originally constructed in the early 1950's. I figured I should leave plastic strips behind the studs only so that the studs are not touching the concrete. I am just wondering if the foam board I was refering to would allow the air to flow in the wall and keep the fiberglass insulation dry. I am also not sure if I should put a poly vapor barrier up over the faced insulation. Maybe a few more folks will chime in.

 

[Scott65]

Any moisture penetrating the wall will lead to mold. You need some type of block lock product to seal the inside prior to covering. If you can isolate the source of the moisture outside, you need to find a way to keep it from soaking through. Block is not a poured foundation wall and does not respond the same to moisture as a poured wall. Unless completely sealed on the outside, it will never be as impermeable as a poured wall. A small spot above grade can be sealed with a block lock product. Below grade will require some sort of excavation to determine the scope of the product.

 

[5lima30]

cutting the plastic out should be sufficient. Once its mostly gone its no longer a vapor barrier.

I would take extreme prejudice against those mold spores before doing anything to cover it up. Seriously, Im talking heavy bleach/water dilution followed by ample dry time and then several days/weeks before doing anything else......and then bleaching it one last time for good measure

I agree completely with srmofo! You might want to put a fan or blower on it to speed up the process in drying it out. As others have suggested I would then apply some dry-lock to the block walls. JMHO.

 

[NickD]

Pictures of both the problem wall from the inside and outside of the building will help us give you better information.

 

[sledzz]

I put 2" foam board on the inside of my 4' cinderblock walls three years ago and as far as I know I don't have any issues, (I haven't removed any pieces to check). I glued them to the block, and then glued on sheet rock and then 1/4 luan board. I have searched for ways to insulate the block but all the advice is to inulate the outside wall, which is not feasable for me.

 

[wnstwolf]

Rat Rod,
Just went through an entire village of homes flodded here in upstate NY. While Bleach is good FEMA was handing out something called Shockwave. Your local paint supplier not box store should be able to get it or look on line. I was a total non-believer of anything better than bleach until I ripped out a basement that also was flooded 2 years back. 1/2 of the space they used the shockwave the other due to running out was bleach. Shockwave kept mold out over 2 years where as the blached walls allowed mold to grow after it dried up. Not cool! For 20 dollar gallon dillute 4 oz or a little heavy per gallon of water you will have more than enough.
I am not connected to the company just had a terrible past 4 months helping people in need and Mold is something you do not want to mess with. Good luck..

 

[R6 Racer]

Pull the poly, clean up mould (don't use bleach!), spray foam insulation, drywall, done!

Steve

 

[Charles (in GA)]

Seal the block first as Scott65 noted and then insulate and sheetrock. I used a block sealer on my parents basement wall in the '70's (I was just a teenager at the time) and it stopped nearly all the moisture from coming thru the block. Would be well worth the trouble and expense.

Charles

 

[cderalow]

using a block filler and painting the outside while creating a future maintenance item, is a good way to help keep drafts from passing through the block along with moisture.

chances are if it's above ground, you either have improperly installed or no weeps in the wall.

 

[bd8134]

Vapor barriers opens up a whole can of worms. See these links..
http://www.energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11810
http://www.epa.gov/indoorairplus/technical/moisture/1_12.html
http://www.greenbuildingadvisor.com/blogs/dept/qa-spotlight/reviving-old-debate-vapor-barriers
I am not a building expert or in this field at all. When I built my garage in MA, cedar clapboard, tyvex, work sheathing, wood framing, open cell spray foam, 5/8" sheetrock and moisture vapor barrier paint. No plastic vapor barrier. My heating is kept at 50 when not used, 65 when working in garage and cooled with ac in the summer.
Ratrodder, cut out the old vapor barrier, the bits left on the backs of the stud are no problem. Maybe seal the wall, inside and out if possible (leave outside till summer), most sealers would never seal 100% so I dont think trapping water would be a problem. Using the foam board you said sounds good, followed by the fibreglass. Or use a spray foam if funds allow, enquire with a few firms as to whether closed or open would work. If you have moisture coming through your wall, most likely still happen even if you use sealer, putting the vapor barrier in behind the dryway may not be a good idea. You will still have moisture coming through the block wall and you could now get mold on the wall, framing, insulation etc. Use a good quality vapor barrier paint and do not use open flue heaters in your garage.
You might be best to discuss it with your town planning dept and see their recommendations.

 

[Zeke]

You might want to read up on bleach for mold. Boric acid powder mixed a cup to a gallon of water will kill mold and prevent insect infestation for years w/o any fumes or toxicity.

 

[Frank The Plumber]

You may not have a water leak, just the temperature differential will cause condensation on the block wall. When warm moist air hits a cold wall it equals wet, wet and cold equals mold.

 

[Falcon67]

You may not have a water leak, just the temperature differential will cause condensation on the block wall. When warm moist air hits a cold wall it equals wet, wet and cold equals mold.

I'd bet this if the exterior walls are all above grade. Even concrete HardiPanel stays cold longer than you'd think. We get some good temp swings here and I noticed that on the couple of days where we went from warm moist 70s to 30s from a cold front in the evening/night that I could feel a little condensation on the inside of my Hardi walls while the inside temp caught up with the outside (new building, uninsulated)

 

[ratrodder123]

Thank you for all the help guys, I'm gonna clean up/treat the mold, seal it up with drylock and commence with the foamboard plan. I too believe its a condensation/temperature related moisture problem. This summer I will have to address the outside as my thin budget allows, hopefully gas wont go as high as they are predicting. Thanks, the wealth of knowledge here is amazing!