I'm working on a 20' single use shipping container build using InSoFast insulation panels (foam insulation with pre-engineered polymer "studs"). I installed all of the panels (which are, by spec, glued in with Loctite construction adhesive, required for side walls, end walls/doors, and ceiling. After gluing all the InSoFast panels inside of the container and allowing time for the adhesive to cure, I applied a layer of 47.75-in x 7.98-ft Smooth Brown Hardboard Wall Panel Item #: 15483 | Model #: SS1254825 (from Lowe's), gluing those hardboard panels to the InSoFast insulation already applied and cured on the ceiling. In addition to gluing the hardboard panels to the installed InSoFast panels, I also affixed them with sheetrock screws in addition to the adhesive, allowing the hardboard panels time to cure.
Next, I planned to glue/screw a layer of 4'x8' sheets of luaun onto the hardboard panels.
Albeit that 24 hours would have been fine to properly cure the adhesive holding the luaun in place on the ceiling, I was unable to continue working for a couple weeks. As I headed in to the container to get ready to affix the luaun (final) layer to the hardboard layer, I saw an extremely large gray mold bloom across the ceiling. It was a light slate gray sort of color, and extensive. In some peripheral areas spotty, but most of the hardboard layer was thoroughly covered with this mold.
Now, I obviously need to clean, treat, and protect the affected area from any future bloom, and I am not sure of the best way to do that.
Basically, at this point all one can view is the exterior surface of the now affixed hardboard panels, but there are obviously certain areas that are invisible now that they are in fact affixed, specifically the surfaces where the InSoFast panels are glued to the shipping container's ceiling, as well as the surfaces between the exterior of the InSoFast panels and the hardboard panels. I have to assume that these areas are likewise inundated by mold bloom as well. So, I need to clean, treat, and prep the hardboard panel layer to receive the final layer of luaun, and while I am doing that I need to address these "hidden" layers as well.
Now, I am sure that the best way would be to wreck and clean/tx/prep, but considering the manner of installation (using construction adhesive to attach the InSoFast panels to the ceiling, and construction adhesive and screws to affix the hardboard panels to the installed InSoFast panels), and the degree of difficulty as well as expense involved (especially considering that the construction adhesive assures that these materials would be destroyed during any removal process). Therefore, I am trying to figure out the best way to handle this.
It seems to me that I need to purchase some sort of biocide (or mix some bleach or similar solution, etc) to kill and clean surface mold on the hardboard layer before I glue/screw the luaun layer onto the hardboard layer. However, its surely best to assume that there is extensive mold infestation within the latent layers, and I need to address that at this point as well. Then, after the kill/clean-up/treat process is completed, to affix (glue/screw) the luaun layer onto the hardboard panel layer (running the luaun panels 90 degrees and/or staggering the luaun and hardboard panels to NOT double up joints together).
Its also my thought that after the clean/kill/tx process is completed, it would be best to use siliconized caulk to seal the the entire harboard layer to prevent any mold within the layers from making their way through the layers and into the container - applying the siliconized caulk to the butt and side joints between the hardboard panels as well as the edges where the hardboard layer of the ceiling meets the side and end walls - and then maybe applying a layer of Kilz to the hardboard layer after the siliconized caulk sealant application is completed to further work to keep any mold trapped within the layers from working its way through the layers and into the living area. It seems to me that cleaning/treating/prepping the hardboard layer and the associated layers therebetween, and then fully caulking/sealing and applying Kilz or something similar to the hardboard layer before applying the final luaun layer SHOULD work, especially if there is a way to assure the best possible clean/kill/tx process for the hardboard layer AND the hidden layers glued between.
I don't know what the best way would be to accomplish this without wrecking anything installed already. Maybe like some sort of pervasive "mold fogging" product? Then, the sealing and kilzing can retain any residual molds within the sealed layers. Is this how to go about it? If so, what products should be used and how should they be applied? It seems like I've read that DIY bleach/water solutions kill and clean up molds as good, or almost as good, as specialized commercial products/solutions/mixtures, but I can't say that for sure.
What should the best process be for this situation, and what kinds/types/phases of products should be used? Is there a solution that can be applied to the hardboard and allowed to dry, needing no rinsing off of the product that anyone is aware of? Or if not, what would be the best way to apply and rinse the hardboard layer without compromising the integrity of the hardboard panels?
If anyone here has any ideas on handling this issue, I would be extremely grateful to hear it!
Incidentally, there is NO leak in the container. The doors had been inadvertently left open, allowing some rain to enter the unit, which is what started the issue.
Also, I am thinking that the InSoFast panels in the end/side walls should also be fully sealed with siliconized caulk or a similar product, and Kilzed as described above as well (between panels and the floor, area where the walls meet the ceiling, etc.). This way, if there is any mold trapped between the layers of the wall(s) and/or ceiling, they would be sequestered from breaching the living area with caulk and Kilz...or similar.
I doubt that there is anything that can be used to saturate the hardboard layer of the ceiling that wouldn't cause swelling/buckling of the hardboard panels (which is why I left enough of an expansion joint between side and end butting of the hardboard panels, and why I believe that stretchable/elastic siliconized should be used to seal off the afore described layers, allowing stretching/compression of the caulk sealing WITHOUT causing the hardboard panels to buckle, pop off, etc). It just seems that much 'saturation' should be avoided, but how to do so in such a manner as to prevent buckling, etc., but still be applied in a solution strength that is effective. For all I know it may be totally OK to saturate the hardboard layer with a bleach solution before air drying same...or not!
I also believe that the best way to seal the end and butt joints of the hardboard panels would be to do so in a manner that leaves a slight 'ditch' or depression along these butt and end joints, which would minimize the chances of telegraphing (causing a bulge in the elastomeric sealant along the sealed joint any time the hardboard panels swell).
Any and all info, including yet surely not limited to the best ways/means/products/solution strengths, brand names, DIY mixtures, etc., would be VERY MUCH APPRECIATED!! Obviously, the cheapest, least destructive, and /or easiest ways to properly accomplish this are favored!
In hindsight there are numerous sensible things I would have surely benefitted from early on in this process, and in the future I will surely handle this sort of situation better - but, at this point I am where I am, and I need to fix that instead of kicking my own dumb ass for my mistakes. Utilizing a cheap, effective, and easy to apply and remove (if removal/rinse is required) DIY solution and process to thoroughly clean/kill/treat molds, both visible on the surface as well as trapped within layers (without any destruction needed to accomplish same) is of course ideal.
Thanks much in advance.