In article , "Pete C." wrote:
Doug Miller wrote:

In article , "Pete C."
wrote:
I think the chance of it being chemical related are close to zero. If it
was a chemical that got on the surface of the siding there is virtually
no chance that it would have any effect on the tyvek underneath.

"Virtually no chance" is completely incorrect. Vinyl siding is *not* air-tight
by any means. Solvent wiped or sprayed on the outside would very rapidly lead
to solvent vapors on the inside.

Not in enough concentration to affect the tyvek. Solvent on the outside
would almost entirely evaporate on the outside as well.

Got any data behind that assumption, or are you just guessing? Even a light
breeze could easily push solvent vapors through the gaps in vinyl siding --
that's why the Tyvek is there, because the stuff is so leaky.

Sure you'd get a
detectable amount on the inside if you were sampling the air inside,
but certainly not enough to do the damage seen on the tyvek.

How are you going to get a detectable amount on the inside if it almost
entirely evaporates on the outside? If you can get a detectable amount on the
inside -- after it's passed through the siding, the Tyvek, the sheathing, the
insulation, the drywall, and a layer or two of paint -- how can you possibly
think that there "certainly" wouldn't be enough to damage the Tyvek? Do you
have any data behind that assumption, or are you just guessing again? Do you
even know how much solvent, or what type of solvent, it takes to do that?

Look, I'm not saying that he absolutely shouldn't open up the wall -- just
saying that he should look at the back side of the vinyl siding first, which
he does not appear to have done. Somebody asked him a couple days ago what the
back side of it looked like; as far as I can tell, he hasn't answered that
question yet.

It's also been suggested to the OP that he perform a test on a scrap of
siding, to see if the stain and the solvent he used will produce similar
damage. He hasn't yet reported results of that test, either.

Both you and the OP have got the idea so firmly fixed in your heads that a
heat source inside the wall is the only possible cause of this problem, that
neither one of you is the least bit willing to entertain any alternative
explanation.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.