How about the "cash is no object approach"? Open the gap to a consistent
dimensions -- one-quarter inch minimum -- to the face of the tongue. This is
a job for a router. Place strip of wood in gap set in water-resistant /
water-proof glue (Resorcinol comes to mind). Trim surface of strip flush
with board siding using olde-tyme block plane.

Of course, no one really pays much attention to the size of the gap and how
it changes from season to season. Which means, in the dead of summer it will
be closed -- or nearly so -- and in the winter "wide" open. Putting anything
in the joint -- caulk or a piece of wood (installed with great pains and at
great cost) -- will tend to make the wood compress or buckle. With the
ultimate result being larger gaps.

Plus, if one were to jam caulk into the joint, without a bond-breaking tape
at the back of the joint, wouldn't one be violating one of the fundamental
rules of sealant application? UNDER NO CIRCUMSTANCES ALLOW THE SEALANT TO
ADHERE TO MORE THAN TWO SURFACES OF THE MATERIAL BEING SEALED!

And, one could argue that the sealant is going to tend to force moisture
migrating through the building envelope -- this is an olde-tyme house
without a proper vapor retarder I imagine -- through the wood siding. Or,
worse, will tend to force the moisture to condense on the backside of the
caulk, where it will saturate the wood and, once the seal is broken (and
oxygen is added to the mix) cause the edge of the siding to rot.

To me the "cleaned" up facade of a building that has been thoroughly caulked
looks like a moulded plastic replica of itself. No sharp arrises suggests no
sharp residents.

Sign me,

Sharp and Square


-----Original Message-----
From: Mike Devonshire [mailto:[log in to unmask]]
Sent: Friday, April 14, 2000 11:06 AM
To: [log in to unmask]
Subject: Re: Flushboard siding


In a message dated 4/14/2000 9:02:45 AM Eastern Daylight Time,
[log in to unmask] writes:

<< They want every joint cleaned out and filled with caulk, ugh.  Or
 should we convince them that it already looks "nice", and clean it up,
 treat it, prime it and finish it?  Can we have some historic
 justification, or perhaps literature to oppose or support such
 treatments?
  >>

Rob,

Assuming the tongues on the horizontals are oriented properly, there is
probably no water getting into the joints. It sounds like the boards have
just "shrunk" to a more or less stable width, which has opened the joint a
bit. I presume that there is a quirk (about 1/16" adjacent to the bead,
which
provides a reveal on that side. If you fill the opposite side it will look
wierd (in my opinion), there would typically have been some gap on that side
as well (which widened and narrowed with the season. It is true that 1/4" is
a bit wide, but filling it will look odd in my opinion. If they insist, fill
it,but with something flexible - or tell them to buy a new ranchburger with
aluminum siding on it.

Twybil