1860 house attic needing to insulated

[NICKODEMOS]

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

[buffalobill]

i went to

and typed in insulation to find:

here's a good one too:

[Colbyt]

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

[m Ransley]

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.

[louie]

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.

[siralfred]

I recommend going to your local public library and asking for a how-to book on weatherproofing and insulation. Time-Life has published several editions that I've found useful.

[tbasc]

Look at Building Science Corporation web site.

Lstiburek says in part: In general, in cold climates, air barriers and vapor retarders are installed on the interior of building assemblies, and building assemblies are allowed to dry to the exterior...

TB

[NICKODEMOS]

Yes I should have said that the woman had three attics. Two she had blown insulation put in and likes the savings on heat. But she needs to keep the third for storage. So it has a wooden floor to walk on (nothing solid just plywood). But it is the backside of the clapboards and has some little holes all over the place.

The room isn't a true cathedral but I do need to do the walls and the roof. It sorta looks like this:

|\\ | \\ | \\ | || \\ | \\

This is a rough look but the left side is the wall to a room. The right is the roof. And the || is a window where the clapboards are. I was wondering how to keep the small holes in the clapboard area from blowing in (some type of fiberglass sheathing like I see on the outsides of houses?). And Also I sorta see what is meant that I need baffles on the bottom. But the ridge vents. Do I need to cut out the top of the roof to put them in?

Also I didn't look but I think that the roof continues on past the wall to the room on the left. so how would I put in ridge vents?

While I am still ready to help the woman out I am seeing that I need alot more information. I am going to follow one guys advice and look at the how to book but any advice that people have is still needed by me.

One other thing. The soffet. It is an old style house. Wouldn't putting aluminum soffet kinda ruin the look?

Nickodemos.

[Colbyt]

Insulating the wall on the left makes sense using standard fiberglass batts, vapor barrier turned to the heated side. Insulating under the existing plywood floor makes sense if it can be removed and replaced. If these two things are done no soffitt or vents are required the roof will have the same airflow afterwards as before. Another option would be just to roll fiberglass batts out over the existing floor but you lose the storage space.

Frankly trying to insulate the entire attic in my opinion is a waste. It might help a little but the payback is no where near what it would be if the above is done. The heat is still going to leave the home and move to the attic.

If you choose to disregard this advice, you need to maintain 1.5" of clearance between the bottom of the roof boards and top of the insulation. This greatly reduces the R-value you can install. The old house is most likely leaky enough that if you do that you can avoid adding soffitt vents. That is just an opinion not a know fact.

As for your holey clapboards you could use house wrap in one big piece folded over the studs, into 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.

Colbyt

[Goedjn]

the stud cavities and back out before you add

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?

[HeyBub]

1860?

I'd see if the local historical preservation society wouldn't be interested - you could probably get architectual advice for free. If you can CLAIM U.S. Grant slept there or the house was a way-station on the Underground Railroad, you might be able to get grant money from the government.*

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*Years ago, my city wanted to give a little old lady $200 each for five old oak trees whose removal was necessary to widen the road. She asserted the trees were hand-planted by King Gustav V to commemorate the city's Swedish citizens who lost their lives in the Great War of 1917. And the trees WERE on the National Historical Registry (due to an earlier claim). The city didn't get out for a paltry $1000. I think they moved the road.

[NICKODEMOS]

OK. This seems reasonable to me. I like this idea best.

Also will do this to just cut out the air leakage. The wall is on the southside so it does get alot of hard wind on it.

Goedjn:

Not it doesn't as far as I know. After all she left it in there without it being insulated now.

HeyBub:

I like this advice alot but it is a small city so they wont have any money. But we will look into it for the gov part.

Thx for all the advice people. All of it was good and helpfull.

Nickodemos