Walls and Ceilings - musty, moldy odor

We live in an old (90-100 yrs) two-story home in SD (cold winters; hot summers). A week ago we had an inch of rain driven by 65 mph winds from the NW. During the storm, rain water began leaking in around the west picture window. I went to the attic during the storm and found the west interior wall of the attic was soaked and water dripping down the framing members on the west wall, as well as down the wall itself. I found that situation once last summer, and vowed to reside the house. Didn't get that done yet. Now we have a musty, moldy, mildewy smell in the house which I suspect is wet insulation and damp plaster (we have plaster/lathe interior walls). The condition exists also in the west bedroom upstairs, which is directly above the affected living room. I'm convinced the leaking is due to dried out tarpaper under the narrow cedar siding. The wind apparently is driving the rain under the siding and through the dried out paper into the wood wall of the house.
I will get the old siding off, Tyvec the wall, and re-side it. THE QUESTION IS, DO YOU SUSPECT I'LL HAVE TO REMOVE THE PLASTER/LATHE WALLS AND INSULATION AFTER THE NEW SIDING IS UP AND RE-INSULATE AND INSTALL DRY-WALL IN ORDER TO GET RID OF THE ODOR?? YOU EXPERIENCED GUYS, PLEASE GIVE ME SOME DIRECTION. Thanks!

bez,

You have a big problem. Based on the age of the home, I am assuming that you are making upgrades beyond the exterior siding unless they have already been done, i.e. electrical, insulation,etc.

The home is a big investment. Your health is even a bigger one!

I recommend being safe. Consider your options. If you reside, what is under the cedar? If we don't have much there then what else has gotten wet? With insulation getting wet and living in an area where winters are cold, you don't have any insulation quality left!

If you are expereincing the odor now, it may get worse and MOLD is an issue to contend with. You should consider investigating various areas of the home and prepare to spend some dollars!

Good Luck and Stay Healthy!

The home has been re-roofed and insulated. The only problem is the siding. Right now, the west and north walls (exposed to prevailing winds, rain, snow) are the problems.

I expect we'll pull down the plaster/lathe and insulation on those walls after the siding job is done. Then we'll re-insulate and do the sheet rock tricks. What a mess that will be. It's not the first, nor the last, of the restoration we'll do in "our old house".

Thanks for the reply.

Here's an article on mold from Reader's Digest "The Family Handyman" magazine:
http://www.familyhandyman.com/200207/fixit/main.html
Good Luck!
Mike

Thanks for the article, Oldguy! I printed it and will heed the good advice when we open our two west walls---which I'm sure we'll be doing! Plans now are to not only open them but to remove the plaster, lathe, and insulation (blown in) entirely from both walls and to re-insulate and dry-wall. Fun times. Thanks again. -bez-