05:57AM | 12/17/02
Member Since: 12/16/02
1 lifetime posts
I live in Michigan. In September of this year, I started building a new 3-bedroom ranch on a crawl space.

I insulated the crawl space walls and bonds with Polyurethane spray foam 3 inches thick.
The heating ducts run through the crawl space and are not insulated.
I have an open heat vent in the crawl space area.
The cold air returns are in the attic and they are insulated
I did not install any outside vents, figuring this would be a "conditioned" crawl space.
I am still finishing inside the house and no insulation is on the walls of the house yet
I heat the house only on weekends while working inside.
I have 3 inches of pea gravel over a dirt/clay ground
I have not yet covered the pea gravel with 6 mil plastic, but plan too.

I've noticed condensation on PVC drain pipes and on the underside of the flooring between joists starting just inside the insulated bond area. It has only been about a 1-1/2 months and already I am seeing some mold/mildew forming on the underside of the flooring between the joists.

I am concerned with the mold/mildew forming so quickly, so I was considering spraying the flooring between the joists (using a garden sprayer) with bleach or TSP to eradicate the freshly formed mold/mildew. I would do this before covering the pea gravel over with a 6 mil plastic vapor barrier. Once that was done, I was going to seal up the entry.

Am I doing all that I can or should do, or do I need to do something more or differently? Any suggestions would be appreciated. Do I need to put a humidifier down in the crawl space for a short period of time to dry it out after spraying or just cover it with the vapor barrier and let gravity deal with the problem? Is the spraying of bleach of TSP recommended or an overkill on my part?

Thank you,

Thomas Miller


03:54PM | 12/28/02
Member Since: 11/06/02
1284 lifetime posts
Spraying a ten percent bleach to kill the mildew is OK. It will probably stop growing once you control thew moisture problem. You don't want a humidifieer which will add moisture. You have ground water rising and evaporating into the air space under the floor and then condensing on the cold surfaces of the wood when you shut the heat off. Alternate cooling and heating encourages this percipitation.
The time to put down a vapour bar on the ground was yesterday. That will prevent moisture from rising. The condensation will happen on the bottom of it. Peastone will likely tear holes in regular plastic when you crawl over it so you will have to double it up with another layer after you are doine working down there and the house is built.
Heating the place all week will also help. Just turn it way down.


Post a reply as Anonymous

Photo must be in JPG, GIF or PNG format and less than 5MB.


type the code from the image


Post_new_button or Login_button

Deep blue grays like the shade shown in this example "have a nautical, serene feeling," says Amy Hendel, designer for Hend... Built on a rocky island in the Drina River, near the town of Bajina Basta, Serbia, this wooden house was cobbled together ... Large steel-framed windows flood the interior of this remodeled Michigan barn with daylight. The owners hired Northworks A... Edging formed with upside-down wine bottles is a refreshing change. Cleverly and artistically involving recycled materials... A Washington State couple called on BC&J Architects to transform their 400-square-foot boathouse into a hub for family bea... Similar to the elevated utensil concept, hanging your pots and pans from a ceiling-mounted rack keeps them nearby and easy... Few projects are more fun than upcycling a vintage piece in a surprising way. Outfitted with a sink and a delicately tiled... The thyme growing between these stepping stones adds a heady fragrance to strolls along this lush, low-maintenance garden ... Decoupage is an easy way to add any paper design to your switch plate, whether it is wallpaper, scrapbook paper, book page... Twine lanterns add pops of crafty—but sophisticated—flair to any outdoor setting. Wrap glue-soaked twine around a balloon ... When securely fastened to a tree or the ceiling of a porch, a pallet and some cushioning make the ideal place to lounge. V... Reluctant to throw away any of those unidentified keys in your junk drawer? Hang them from a few chains attached to a simp... A stripped-down model, sans screened porch, starts out at $79,000. Add the porch, a heated floor for the bath, and all the... Salvaged boards in varying widths and colors make up the dramatic accent wall in this attic space. The high-gloss white of... This garden shed has been decked out to the nines. Designer Orla Kiely created the intimate home for a flower trade show, ...
Newsletter_icon Google_plus Facebook Twitter Pinterest Youtube Rss_icon