"NICKODEMOS" wrote in message
...
Hell all. Did a search on here and found some answers but not all. So
here goes my questions.

The house was built in the 1860's. Doing an attic where I will be
insulating the walls and ceiling (cathedral I think it is called). It
will be against the old clap board siding with it's many tiny holes in
it. So how would I go about making it air tight before I put the
insulation in the walls? Or should I?

Live in the Indianapolis area so any special needs? Vapor barrior?

Also someone said something about putting in soffet? And something
about the bottem 12" remaining free of the insulation for venting.

Anyways I am looking for all information I can get since I am doing
this for an older lady from my church and don't want to screw it up.

Oh and if you have some link that would be great.

Nickodemos



Unless the attic is living space there is little value in insulating the
walls. Ditto the roofline.

The number one heat loss factor is through the ceiling. R-38 in this area
and some caulk for air infiltration could easily cut her heating bill in
half. If you insulate the living space below from the attic above that is
your greatest payback. Sometimes with a floored attic this is hard to do.
Is that you situation?

It is important to allow for airflow for the roof in situations where the
roof rafters have insulation added between them in a true cathedral ceiling
situation. I doubt you have that in pre 1900 construction. Also, I think
you have not clearly understood something that someone has posted about
soffitt and the bottom 12".

Post again with more info and myself or one of the regulars will try to
answer you questions.

And thanks in advance for helping the old folks.


Colbyt

Is it a heated attic, unheated you insulate the floor, if heated and do
the roof deck you need an airspace between the deck and insulation with
venting, a soffit and ridge vent. You better learn before you mess up
her houses design.

The soffit will be a horizontal panel (vented) between the lower edge
of the roof and the wall of the house. You'll also need a ridge vent
on the roof as others have mentioned. Then, with a cathedral ceiling,
you need to provide a space on the underside of the roof
sheathing/boards for air to travel freely from the soffit all the way
up to the ridge vent. There are styrofoam baffles that can be easily
stapled in place against the inside surface of the roof. Then you can
fill the remaining cavity between the rafters with insulation. If this
is living space, get the insulation batts with a vapor barrier and
install with the vapor barrier down (towards the living space). Then
you can finish the ceiling with drywall or whatever you feel like
doing.

If this is not heated living space - then as others mentioned, you
still need the soffit and ridge vent, you'll want at least a row of the
same baffles down near the soffit. Then you can insulate the floor of
the attic space (ceiling of the room below). The baffles will ensure
that air can get past the insulation and flow up into the unheated
attic then out through the ridge vent.

the stud cavities and back out before you add
your fiberglass batts.

IMO the little old lady needs to choose warm and cheap or storage for junk
she doesn't need.

Does the stuff being stored need to be in a climate controlled
environment, or can you just insulate the attic floor and
leave the storage area cold?