Exterior wall insulation

[Dean2]

Jeeez Louise! Look at all My spelling errors! I'm gonna go hide in a corner!
Dean

[waitingtohear]

I do not plan to take off the outside aluminum framing nor replace with Tyvek even though this would be the ultimate solution. If I were planning on keeping this place for another 20 years I would do it. But I'm going to be selling it.

I can only afford at this time to finish the job I started (which was purchasing wallboard to replace my old wallboard).

After tearing down the wallboard is when I was introduced the the world of vapor issues.

I figure I have three choices at this time, while I still have the walls open:

A) I could tear down the old plastic sheeting which would allow the insulation to release it's moisture and dry out faster (although it would expose the insulation to direct contact with aluminum siding and outside environment overall)

B) I could PATCH the rips and tears in the plastic and assume it's keeping moisture from entering the home, as well as wind from deteriorating the insulation faster.

C) I could IGNORE the rips and tears in the plastic and hope that I'm getting a "middle of the road" solution. Just enough ventilation to allow moisture to leave the home, yet enough plastic that covers most of walls to protect from outside winds and other pollutants.

My overall confusion on making a final decision is:

I'm not sure if the outer plastic is actually helping in any way to keep the moisture out or is it adding to the problem?

I see lots of condensation between the outer plastic and the outer aluminum walls, in the kitchen area especially.

I don't know if the plastic is keeping the moisture from entering the inside or did it accumulate FROM the inside and work it's way to the outer side of the plastic?

Since I keep hearing that vapor barriers should always be on the inside walls behind wallboard, I can only assume the moisture is escaping from the inside and working it's way to the outer plastic at which time it condenses into water which gets trapped between the plastic and aluminum siding until it gets warm enough outside to fully evaporate.


Anyoo, which way would YOU go with this and why?

My project is on hold until I know for sure which way to go....

Thanks to all who have replied so far!!!

[steve]

I would add Tyvek to the outside from the inside covering the studs in a in/out fashion. This would stop air movement from the outside (air movement with condensation causes mold on cellulose material) and allow moisture to escape. This would also allow a cavity to install fiberglass batts which would be the interior moisture barrier. You could also put plastic on the inside over the batts, just behind the drywall. Dont forget to remove existing plastic from outside(best you can)

[Jim from Canada]

You definitley need to remove the exterior plastic. Vapour barrier is for the "warm in winter" side of the insulation only. Meaning, betwwen the insulation and interior sheathing (gyproc normally). The exterior plastic will cause problems with condensation. To get rid of it you need to strip the siding off. If you go that far, put on an air infiltration barrier (tyvek, or similar). What I am doing is removing the siding, adding 7/16 OSB to the exterior, then 1/2" isocyanurate insulation with a foil covering (the foil acts the same as tyvek). Then re siding. It is a multi year project that I am picking away at. As for weight, I have 2x6 wall construction, so I am confident in the unit being able to handle it.

Jim

[Dean2]

Since the siding is staying put then steve may have the idea to suit it for quick sale,,,that is,*if* You want to give the future buyer a mid-road solution.

Pulling the siding sheets,adding tyvek,then re-install the siding with slightly longer screws with fatter threads is recommended.there's no need to go too much longer with the screws because the girt board(horizontal ones)is only 3/4" thick anyway.

I forget what the siding is exactly but I'm assuming it is vertical 3'x8' sheets,,wich,,to a point,is kind of a solid vapor barrier anyway,almost defeats the purpose of tyvek.

Short answer,without going whole-hog on the remodell,,,I dunno.

Dean