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powder post and ground seal issues


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This mornings inspection was of a house built in the 1930s. It has suffered structural failure (deflection in 6x6 beams) between supporting posts. A carpenter sistered up suspect joists and poured some new footings adding posts. There are around 30 posts under this house.

Issues and points

1. recent vapor barrier (6mil poly) has white mold under surface in many areas(dirt crawl space 3 Ft clearance)

2. some existing posts have decay at pad area(not 6'' above grade)

3. water infiltration at skirting around crawl space.(exterior grade above crawl space grade)

4. Some new structure(1 year old) has symptoms of decay. Only close to grade.2 issues powder post and rot from moisture.

5. Has the powder post beetle gone?

6. Has anyone treated the beetle before

7. This is a vented crawl space should it become heated? removing mositure?

8. Bug treatment?

9.a new poured ground seal would be below exterior grade.

It would be difficult to create a water tight barrier 6'' above grade between supporting posts from the interior

Thanks for the input guys.

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I am not exactly sure what you are looking for but here is my $.02

I am also going to make the assumption that this house is post and pier and does not have a foundation.

1. White fungal growth under the vapor barrier is nothing to worry about. I see it all the time.

2. Posts that have decay should be replaced. If the pads aren't 6" above grade recommend using pressure treated lumber for posts. Cut ends should be treated with appropriate end cut solution. There should also be gasket material between posts and footings to prevent wicking of water from the concrete.

3. What is the grading on the exterior of the home. The soil should slope away from the structure to keep surface water from running into the crawl. Where do the downspouts discharge? Will this water run into the crawl?

4. These are not powder post beetles. Powder post beetles typically infest hardwoods such as oak. Since the framing is probably fir this will be an anobiid beetle, common name is death watch beetle, and no they are not gone. From the picture it looks like there may also have been some damp wood termite activity. It is hard to tell because the picture is blurry.

With anobiids all heavily infected wood should be removed. Once repairs have been made all the insulation should be pulled down and all exposed wood should be treated by a pest control operator. They will usually spray everything with a borate solution. This won't kill the larve in the wood but once the beetles emerge and lay eggs the treatment will kill the eggs and break the life cycle.

7. As long as the crawlspace is properly vented and there isn't standing water on the vapor barrier there should be no need to heat it.

I hope this helps.


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I agree, John. Pic 2 shows termite damage. In this case, they could actually be subterraneans, but who cares? Termites have been at work there.

We missname the anobiids here, because the pest guys call them "powder post beetles" all the time. We don't use oak for building, and there are no real East Coast Powder post beetles here. But you are correct, and yes, if there has not been a treatment done, the beetle larvae are still at work there as well.

If they think that shored-up wood skirting is a good fix for that house, they are sadly mistaken.

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I agree with the Johns on all points.

I'd also add that many lenders won't lend on a house that lacks a proper perimeter foundation. The engineered fix that I've been seeing is a concrete perimeter footing with a PT-framed foundation wall between the footing and the sills.

Whoever buys that house better be prepared to deal with all of the crap that Lee found as well as all of the stuff that's concealed that he wasn't able to find.

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"If they think that shored-up wood skirting is a good fix for that house, they are sadly mistaken. "

The 2x6 framing (vertical) on the left of the photo is nailed to the 6x6 posts to add additional support to the 2x10(horizontal) that is bolted in the existing 6x6 beam to lend support. I know poor images!

I reccommended pulling insulation down sistering up joists after a treatment has been sprayed. and pouring a concrete ground seal raising structure out of dirt.


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