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Replacing Tar Paper from the Inside

2032-Nick's picture

I am remodelling my bathroom (first remodel for me).
The house is old, 1900, and one wall of this bathroom is an exterior wall of the house. Yesterday, we took the whole room down to the studs and discovered on that one exterior wall that the tar paper underlayment between the exterior siding and the studs was peeling off badly and mostly absent in large areas. My hunch is there was a bad leak from the bathroom immediately upstairs at some point in the history of this house.

So I've got two questions for the experts:

1) Is it imperative that I replace that rotten weather proofing?
2) If yes, is it possible to replace or otherwise repair it from inside the house, while I have that wall open?

I have pictures I can send to anyone who really wants to diagnose this further.

Thanks, Nick Merz

(post #101100, reply #1 of 34)

I have a client with an older building near the road. It's siding over studs, no felt or insulation. He has asked me a couple of times if I could somehow weatherize and insulate the building from inside, without removing the siding, so he won't have to get a permit.


Nope. Gotta remove the siding and install either felt, housewrap, or whatever you like over the studs or over sheathing. Then replace the siding and trim.


I suppose you could entertain some sort of spray foam insulation fully filling the wall cavities, but I don't think that addresses the issue of protecting the studs.

(post #101100, reply #2 of 34)

Is the siding leaking? Do you need protection from outside leakage for the studs, or just an air infiltration barrier? If the latter, you should be able to fit pieces of housewrap into each stud cavity, stapled and/or taped to the studs.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #101100, reply #3 of 34)

Consider this: Those studs have lasted a long time so far. The felt between the studs and siding is probably still there. I'd think about putting Tyvek neatly between the studs and tight against the back of the siding from the inside. Staple it to the sides of the studs. Caulk it if you must be anal. Then insulate and add a good vapor barrier on the inside of the studs.

This is a bathroom right? It's a small percentage of the total house exterior and not worth getting bogged-down over.

Al Mollitor, Sharon MA

(post #101100, reply #4 of 34)

Gentlemen, I respectfully submit that housewrap added to the cavities might actually speed the degradation of the framing. Moisture has previously had a way to migrate into the wall cavities and thru into the house if it wanted to. With tyvek there is will stop and the back of the siding will be wetter than before. That would concern me.


I could be completely full of sh!t. Advice worth price charged.

(post #101100, reply #7 of 34)

Housewrap will not keep moisture from migrating inward or outward. It will, however, keep cold air from migrating inward and promoting condensation in the walls. Combined with a proper poly vapor barrier on the inside housewrap should be fine.

Look at it this way: If Tyvek would cause rot by trapping moisture, felt, which does not allow moisture migration at all, would cause more.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #101100, reply #8 of 34)

I'm not persuaded. Felt does permit moisture migration, both thru the material and thru the laps. Tyvek stapled to the inside of the studs in sections will not prevent air movement very effectively.


As long as it's not my job or my house...

(post #101100, reply #9 of 34)

Air movement and moisture migration are two entirely different things.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #101100, reply #10 of 34)

When he said that I was thinking of a different problem.

You don't have a "wall" barrier between the siding and the studs anymore with overlaps from top to bottom to shed water.

That with pieces in each bay and not way to to have an higher lay to lap over that it can trap water that runs down into the cavity.

. William the Geezer, the sequel to Billy the Kid - Shoe

(post #101100, reply #11 of 34)

I still haven't figured out how it is that all this water is leaking behind the siding. You guys must have some pretty porous lumber.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #101100, reply #19 of 34)

"Is the siding leaking?"


"I still haven't figured out how it is that all this water is leaking behind the siding."


 


all siding "leaks" ... there is no "waterproof" siding material.


Jeff


    Buck Construction


 Artistry In Carpentry


     Pittsburgh Pa

    Buck Construction

 Artistry In Carpentry

     Pittsburgh Pa

(post #101100, reply #22 of 34)

I'll admit my experience is limited, but I never seen evidence of signficant siding leakage. Resided our house and the only evidence of leakage was around windows where they did a carpy job of flashing and caulking. And that was pretty minor.

Only case of bad leakage I've seen was a house in TN where the problem was some very old plastic junk that was badly cracked, and had been for decades.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #101100, reply #23 of 34)

everything "leaks" ... even brick.


the trick is giving the water a good escape route.


Jeff


    Buck Construction


 Artistry In Carpentry


     Pittsburgh Pa

    Buck Construction

 Artistry In Carpentry

     Pittsburgh Pa

(post #101100, reply #24 of 34)

This is great advice, everyone.
Some more details on the problem :

+ Location is San Francisco, CA, so lots of rain in winter.
+ The wall is an exterior wall, facing into a lightwell.
+ Looks like the wrap between siding and studs is tar paper -- could be original 1900 construction, maybe newer since house was re-vamped by SF housing redevelopment agency in the 60's (though I don't think they touched the siding then)
+ The siding that is exposed beneath the deteriorated tar paper is wood... your expertise is probably better then mine at what kind. (douglas fir?)
+ The deteriorating paper is shaped like a parabola around the sewer pipe of the toilet in the unit immediately upstairs. My diagnosis is the damage came from that toilet leaking at some point in the last century, not from water coming in from the light well.

-Nick

(post #101100, reply #30 of 34)

For just that one open wall, I'd strip the old paper, patch any weather gaps, prime the back of the siding (may as well do the studs too, while you're in there), staple-up housewrap against the back of the siding if you're concerned about air leaks, insulate (foam if practical), install an airtight vapor barrier on the inside, wall finish, done.


}}}}


PS: My house was also built in 1900, but way up near the Continental Divide in Colorado.  It's balloon framed with roughly (very roughly) 2-1/2" x 4-1/2" pine studs, 1" fir boards on both sides, and mine smelter slag filling the stud bays.  The exterior horizontal sheathing was "chinked" with tiny strips of wood whittled to fit, and all that was painted as the finished exterior.  The interior side of both the exterior and interior sheathing was plastered with newspapers, which make for interesting reading during renovation lunch breaks.


Edited 5/3/2006 8:48 pm ET by Ted Foureagles

(post #101100, reply #12 of 34)

In any event, with some care during installation (and maybe a piece of flashing wedged in at the bottom, with the wrap stuck between it and the siding), the wrap would be better than nothing in terms of keeping rain leakage out of the wall.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #101100, reply #13 of 34)

There are several issues here. What type of exterior wall finish does he have? If water gets blown through the cracks, how will it get out? I would spray a liquid sealer on the inside of the exterior wall surface. Then insulate, then put the interior wall surface. If you seal both inside and outside with a vapor barrior and some water gets into the wall cavity, then it will rot. Now there are plenty of ways for the water to get out, but if you add isulation to this space, it will act like a sponge and hold water.

Best method that can be guranteed, remove exterior finish and do the job right. Everything else is a gamble with not enough info here to make the best recommendation.


Edited 4/30/2006 11:59 am ET by KirkG

(post #101100, reply #14 of 34)

Read my lips: House wrap is not a vapor barrier.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #101100, reply #15 of 34)

Hi David. I suggested house wrap inside the siding because it's supposed to stop air infiltration (cold wind), but allow excess water vapor to move through. The vapor barrier I suggest for the inside is supposed to keep warm, moist bathroom air from getting into the stud cavities.

I think the main point here is that the house is over 100 years old and doesn't seem to be rotting to dust. I think the original poster could afford to let this issue slide after reasonable care from the inside and get his bathroom back togehter without tearing the siding off the outside.

Al Mollitor, Sharon MA

Just because it survived for (post #101100, reply #32 of 34)

Just because it survived for 100 years doesn't mean that it will survive being partially improved.  If you add insulation and other barriers to air flow, you'll increase the performance of the wall, but you'll also decrease it's ability to dry.  What works in a wall behind a good moisure barrier may cause rotting in a house with no such barier.  If you take the amount of water entering through an old-style wall and add modern barriers inside the wall, you'll combine larger amounts of water entry with lesser amounts of air drying and your wall will probably rot.  

(post #101100, reply #27 of 34)

> This is a bathroom right? It's a small percentage of the total house exterior ....


True, a one-bathroom fix isn't worth the bother.  But it would be a big mistake to assume that the moisture barrier failure is limited just to this one room.  On a building that old, the tarpaper may well have failed everywhere.  Mine's from 1926, and the paper is shot everywhere.  Getting a look at it in a few other places would be good, if it could be done without too much damage and effort.


 


 


-- J.S.


 

 

 

-- J.S.

 

(post #101100, reply #28 of 34)

John, not disputing that your felt paper was shot, but I have worked on many homes where the paper was at least 100 years old. In every case the paper was in excellent shape. That is why I still use 30 lb felt instead of house wrap.30lb felt today is about equal to 15lb felt from years ago.


mike

(post #101100, reply #29 of 34)

While it's very true that old tarpaper may be in good condition, if it's failed in one room, it's probably worth spot checking other parts of the building.  It's good to have a complete idea of what's wrong before deciding what to fix when.

 


 


-- J.S.


 

 

 

-- J.S.

 

(post #101100, reply #5 of 34)

Put a vapor barrier on  the studs before you apply the sheet rock or whatever the wall finish will be.


mike

(post #101100, reply #6 of 34)

If you do,start at the top and go down.

(post #101100, reply #16 of 34)

The house I have is newer (1906) remove the felt and backprime the siding with a good paint Zinzar 123 or the eq.  The felt is a vapor barrier, the paint will do the same thing.

(post #101100, reply #17 of 34)

I'm having a hard time seeing what's going on. Is there no sheathing on this place? If there is sheathing who would put tar paper on the studs under the sheathing?


Maybe the sheathing is that paper faced fluff we used to call beaver board and the paper is coming off that.


What's going on?


Ron


 

(post #101100, reply #18 of 34)

No sheathing. Not at all uncommon in older houses.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #101100, reply #25 of 34)

Quite a few older homes were built without sheathing. The paper was nailed on the studs and wood clapboards over .The clapboards were not beveled either. Same thickness across the width, but nailed up like bevel siding.


mike

(post #101100, reply #26 of 34)

I built a shed like that once.

(post #101100, reply #20 of 34)

Okay.....


First things first..... Where is your jobsite located at, and what kind of stud and "sheathing" are we looking at? Is the outside cedar/cypress/longleaf weather boards? Brick/brownstone/stucco?


More info if you may?? Also most homes built before 1938 usually don't have an exterior "sheathing" installed on them. They have weather boards nailed directly onto the studs (sometimes with tarpaper) or they have masonry facades installed with some form of lath, either metal or wood, to bond the masonry to the wooden structure. Again, depending on the locale...