Need advice on weatherproofing/insulating interior walls

My 1963 Eichler had poorly installed R-9 fiberglass insulation. Replacing it with R-13 has made a big difference, especially in one corner room. I considered R-15, which is the thickest bat you can put between 2X4 studs, but it isn't available in Northern California, except by special order, and at a 50% premium.

The R-13 bats sold at Home Depot (not an advertiser on this site) have these cool vertical perforations which really make installation easier. Be sure to wear the proper safety gear http://tinyurl.com/2k2c4 For instance, don't use cheapo single strap dust masks which aren't rated for fiberglass.

Be careful about "sealing" the walls. For instance, Tyvek sheeting would commonly be used in new homes to prevent air from entering/leaving the walls. But if you seal up your Eichler, you'll create a humidity problem. Which you could fix with a heat exchanger, etc etc. Caulking open holes certainly makes sense.

I agree the last post, I'd like to add a few things. I prefer to use encapsulated insulation (R-13) on exterior walls for three reasons:

1. It is full encapsuated in plastic and not paper, so it helps to act as a vapor barrier (and resists mildew better).

2. It has far less irritants (some products claim to be "virtually" itch free),
you should use it in a well ventilated area and wear a respirator, gloves and long sleeved clothing if you are sure how sensitive you may be to this product.

3. If you are purchasing this at a home improvement store (Lowe's, Home
Depot etc.-it's okay to mention those places on the network) you'll also find that product is generally less expensive per square foot.

As far as installation goes, place approx. 4'X2' plywood on the ground. lay insulation, writing side up on plywood, measure needed length or width, take a wood straight edge (2"x4" is what we use) compress insulation with straight edge, cut with sharp razor knife, install in wall, staple. Done.

To seal water from the exterior, there shoud be a #15 felt paer or tyvek product in place. that's all that is needed to keep water out, unless there are penetrations in the exterior wall, If the hole is the size of a quarter or
smaller, it can be filled with sealant (like paintable silicone), if larger, some siding repairs may be in order
One last thing on insulation, if you are insulating
interior walls for acoustic insulation, Owens-Corning has a product available at the Home Depot Pro store (Colma,Milpitas) that costs about the same as the encapsulated product, and is designed specifically to work better than R-13, to block noise. I've got to get to the job site, my employees are probably on a long coffee break.

Thanks- this is helpful. I have a heat exchanger (see last article in Fall's 2003 Eichler Network Snail Mail Newsletter) so I have no problem sealing my house better (I've done the windows and roof already).

Regarding Tyvek. I've seen this wrapped around a new house but I'm not sure of the procedure of how to install it on an existing house. I checked their website but they didn't have any directions for existing homes.

1. Should I install it before the insulation next to the siding or over the insulation?
2. If under the insulation, how specifically should I install it between the studs? Should I cut it to exactly the opening as I would insulation or should it be bigger and sort of folded so it gets attached to the studs?

Thanks, Lynn

Installation of Tyvek (or ASTM#15 asphalt saturated felt paper, which is on every one of the dozens of Eichler homes that I've opened from the interior or exterior) is done over the rough exterior framing, between the exterior siding and framing. it alone protects the rough framing from water related problems, and is sufficient to do so by current building standards. It is installed after the exterior siding is removed; there is no other way to practically install it. If your siding is free of dryrot fungus, termites, or other wood destrying organisms, it is not structurally necessary to install either material. If you are having a moisture/humidity problem (typically symptomatic of mildew, softened drywall, or de-laminated 1/4" plywood wall coverings), then sometimes it is necessary
to take further steps to seal the exterior prior to re-covering with replacement siding. We have good results with correcting these types of problems and mildew abatement, but because each set of circumstances is different, it would be unprofessional and irresponsible of me to give general do-it-yourself advise to remedy this type of problem without evaluating the situation personally (an improper repair can lead to more problems). If these conditions are not present, good for you, there is less work that you need to do. If the replacement of the exterior siding is not needed, I would not recommend undertaking the expense, unless there is a desire to replace with new material for aesthetic reasons (i.e. sun damaged siding). If that is needed, Jeff Nichols does manufacture siding (listed on this website) and we manufacture siding as well (in limited quantities), (Also on this website, or you can contact me via Email).
I am always happy to answer Eichler Homeowners' questions, so feel free and email me any time. Hopefully I answered your questions; if not, post a reply. Good luck, Jon.

Jon- Thanks for the clarification on Tyvek. Our siding is in pretty good shape and but a good look at the interior side will hopefully confirm that. I planned on a termite inspection when the walls are open. May call you if things look suspicious! Thanks for your guidance on the msg board. Lynn