I'm guessing if you are in an "A" zone you obtained an Elevation Certificate prior to building. The elevation of the crawlspace is considered the "top of bottom floor" and the finished floor of the first floor is considered "top of the next higher floor" when dealing with an enclosed area such as a house on a conventional foundation as indicated as C2a and C2b on the certificate. C2c is "bottom of the lowest horizontal structural member (V zones only)" ; "V" zones are coastal so if you are in an "A" that is in a community that also includes "V" zones I'd make sure somebody isn't confused about that.

Hate to bad-mouth Thompson water seal, but my experience:

Built a big deck on my own house in 1995. To save money, didn't use pressure treated wood. Sprayed Thompson's on posts, beams and joists. 15 years later, it was all rotten and I started over....Lesson learned.

I'm not suggesting that it be used on the outside of the house. I'm suggesting that a product called Water Seal be used in a basement as a moisture resistant barrier for code compliance.

BTW, as bad as Thompson's may be, you used non pressure treated wood outdoors, and you are blaming the coating that you put on it for its failure. Do you really think that is a valid test of any product ?

''AND 15 YEARS LATER''... :rolleyes: I suppose you only put one coat on as well, as opposed to yearly renewal. I deal with code compliance on a daily basis. As I said, the inspector is looking for something he can sign off on. Moisture resistant coating - Water Seal. See a correlation ? I actually use Woodlife Classic wood preservative as a wood preservative. However, there is nothing in its title that would imply it is to be used as a Moisture Barrier.

The title ''Water Seal'' pretty much says it all. I would have called the inspector yesterday, and I would be putting it on today with a respirator and a sprayer of some sort, even a garden sprayer. Then I would take a picture of the basement with the empty cans stacked up in the corner, and I would email it to the inspector. They love that , it makes their job 100 times easier when everybody does that.

Don't overthink this. FWIW, I use Fir for framing, not candy wood. But what's done is done.

http://www.rustoleum.com/product-catalog/consumer-brands/wolman/woodlife-classic/


Wolman™ WOODLIFE® CLASSIC Product Page -...


... Wolman™ WOODLIFE® CLASSIC. This 100%-clear formula repels water and contains nearly ... preservative protects against ... WOODLIFE® CLASSIC ...

This is what I would use on the inside of my house. Search is your friend.

CPES Clear Penetrating Epoxy SEaler. It is used in wood boat construction and repair. It is a thinned epoxy that penetrates the wood fibers and essentially encapsulates the wood in plastic. There are several commercially available CPES products on the market. Just google penetrating epoxy for a multitude of choices. I happen to like Smith & Company or you can use regular epoxy and heat it slightly. As epoxy heats up its viscosity gets thinner. You can roll or brush it on the wood

Wow that one's news to me. Is this a City of Mt Pleasant thing or is it county-wide?

edit: We're just off the Ashley River across from Wagener Terrace and one of the best things I did was encapsulate the crawlspace and keep a dehumidifier down there. I can't recommend doing it strongly enough. Maybe it would also help get you out of this floor joist problem with inspection?

This statement is actually wrong. Rot only occurs when four things are present for the mold spore to grow. A food source (the wood) air, moisture and heat. Remove any one of the four and rot will not occur. Air flow will aid in evaporation but in your application unless you intend to add exhaust fans you most likely will not have enough air flow to prevent rot form occurring.

From what I gather from your post you failed your framing inspection? If that is the case wouldn't the path of least resistance be to just replace the bridging with treated lumber or metal bridging?

Spoke to the head of the building dept. He said it should have been a class 4 or 5 material.

The good news is that he said I could use a brush or spray on product to make it water resistant. Just need to pick one, submit and get approval.

He said don't bring in a can of Thompsons water seal.

This is a local code ordinance they have, not a state or national code.

I'll sleep better tonight than I did last night.

It looks like this is the ordinance he is enforcing. This is from the City's Code of Ordinances.


STANDARDS FOR FLOOD HAZARD PREVENTION

§ 152.20 STANDARDS IN GENERAL.

In all areas of special flood hazard the following provisions are required:

(A) . . .

(B) . . .


(C) New construction and substantial improvements shall be constructed with only flood-resistant materials below the design flood elevation;

Fortunately flood resistant isn't necessarily the same as pressure treated, so it sounds like the building official is giving you a good workaround. he has the authority to grant waivers for substantially similar materials and methods, so you should be good to go.

You would need an insane amount of airflow to prevent rot, enough to bring up the temperature in the crawlspace above the dew point. Around here in the nastier time of year it's not uncommon for the dew point to get close to 80 with the crawlspace ambient temperature less than that. You get condensation all over the place. It's better to encapsulate and put in a dehumidifier here IMO.

Add leaking HVAC ducts running through the crawlspace like some have and now you have a real recipe for disaster!

Whew, looks like you have the info needed to be able to meet the code requirements.
Now you will want to look at the reason for the requirements in the first place. Is there a likely chance that rot in your lower framing is a possibility. What steps will most reduce that possibility. It's one thing to meet code, Another to build for longevity and low maintaince.

Glad you've found a way over this hurdle .

Cheers Richard

In talking to the building dept head, it was an issue with getting wet in a 100 year flood plain, not everyday rot and bugs (although I can see it helping).

The products you guys mention seem to cover both bases: water proof and bugs/mold etc.

Another BS of jumping through more hoops. Spray or roll that stuff (whatever you like to use) and get pass code and move on.

You would need an insane amount of airflow to dry the wood. Encapsulating the wood stops moisture infiltration and keeps oxygen at bay.

Hit it with this, and tell him "Fine, here ya go"


http://ecx.images-amazon.com/images/...L._SL1500_.jpg