Exterior Wall Insulation

[StanD]

40 year old MH. What R value should I be using? Present insulation is 1" thick.

Time to fix some dry rot around a window. I pulled the paneling and the header, trimmers, sill and floor are damaged. I'll have to replace the framing and repair the floor.

Wall is framed with 2X4s but the jack studs are 2X3 (why is this?) and the wiring that passes under the window is in the middle of the opening.

3 different contractors flaked out so I am doing this myself.

[Greg]

With a wall that thin you are limited as to what you can do. You can only put just so much fiberglass in there. Foam may be an option worth checking, I'm not sure what the R value of 3" foam is and what the costs would be.

Greg

[ponch37300]

2x4 framing will accept R13 fiberglass insulation. The thing with fiberglass insulation is you don't want to cram it in there, if you compress it to fit more insulation you actually decrease the R value. I'm sure the 2x3 jack studs or cripples are just a cost saving measure, I've learned not to question why they do what they do with mobile homes! For the wiring just pull the insulation apart in half as high as the wiring goes and slide one half over the wire and the other half in front.

[bobfather99]

Is there any kind of vapor barrier??

[StanD]

No vapor barrier.
The previous owner had double pane windows put in and they did a terrible job with the flashing and the caulking. But it was 14 years ago.

Noticed something else. Whoever put the rain gutters in drilled into the siding. There's a bunch of screws sticking through. But, there are no signs that water has come in around the screws. Still going to seal up the guttters.

Thanks for the input.

[bobfather99]

You can remove the gutter screws one at a time and seal them up. Give a drop or two of silicone around each screw head to double seal it. Should be ok.

Couldnt hurt to cut out the bad caulk job and start over. Start at the roofline and work your way down, sealing as you go. That way you know you got the window area sealed up, keeping moisture and drafts out.

[JeffInFL]

for what it's worth, i put R13 in my 2x3 framing. It fit pretty well .. not like I had to compress it much to get the drywall over it.