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Discussion Forum

30 lb roofing felt as building paper

angusj | Posted in General Discussion on June 9, 2009 07:54am

Does anyone know what the effects of having 30lb roofing felt on the walls would be?

I have been asked to fix a reno that has gone horribly wrong.  One of the countless mistakes is they papered the building with 30 lb roofing felt.  I have never considered this and I am wondering what the long term effects of this might be.  We are fixing other things with the install (upside down windows, no over lap, no flashings, sun damage, etc.)  so it will all come off anyway but …  any ideas what would happen if we were going to leave it.  Thanks

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Replies

  1. bobtim | Jun 09, 2009 08:03am | #1

    I really don't think it is a negative. Although I usually use #15.

    Might be a bit more difficult to install.

    1. angusj | Jun 09, 2009 08:42am | #2

      15 lb roofing felt on the walls or 15 minute tar paper?

      Here we use 30 minute tar paper, half lapped or 60 minute 2 in lap.

      1. User avater
        Matt | Jun 09, 2009 02:30pm | #5

        Is it the thickness or just the fact that it is felt that concerns you?

        BTW, you said: >> 

        15 lb roofing felt on the walls or 15 minute tar paper?

        Here we use 30 minute tar paper, half lapped or 60 minute 2 in lap.

          << 

        Here we get #15 or #30.  As in number 15 or number 30.   As far as I know the 15lb and the 30lb was how it used to be graded - I think maybe it was 15lbs or 30 lbs per square.  With everything getting cheaper what is available here is not actually up to the old standard of measurement and they went to the #15 as opposed to the 15lb.  I do'know  maybe if I special ordered?

        Here #15 or #30 felt is used under stone and brick veneer as standard practice all the time.  

        When you say 30 or 60 minute, does it actually say that on the tar paper roll?  I have not seen that here, but maybe they sell different stuff where you live.  I kow there are different types of building paper (not tar paper (asphault impreginated)) that have a minute rating, but I have not seen tar paper like that.

        1. User avater
          PaulBinCT | Jun 09, 2009 02:54pm | #6

          I want to hear about the upside down windows...PaulB

          http://www.makeabettertomorrow.com

          http://www.finecontracting.com

      2. bobtim | Jun 09, 2009 06:17pm | #9

        I use #15 on walls usually and prefer to use #30 on roofs. I can't find 15 or 30 pound felt anymore.

        I don't know what "minute " paper is. What is it?

        What's the diffrence between tar paper and roofing felt?

        1. User avater
          xxPaulCPxx | Jun 09, 2009 07:16pm | #10

          I don't know what "minute " paper is. What is it?

          I'd say 30 minute paper take twice as long to install as 15 minute paper.

           

          :)

           

          Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!

          Look, just send me to my drawer.  This whole talking-to-you thing is like double punishment.

          1. splintergroupie | Jun 09, 2009 08:26pm | #11

            Google to the rescue:http://www.halind.com/content/building_paper_faq.html"Q: What do the designations of 30 Minute and 60 Minute building paper mean?
            A: These designations refer to a moisture resistance test which uses a moisture sensitive dye as an indicator. This is an American test and is not officially recognized in Canada. HAL INDUSTRIES is the only Canadian manufacturer of building paper to rate our building papers according to this test."Odd, since the poster if from British Columbia. The reno looks like it's in capable hands, eh?

          2. MikeHennessy | Jun 09, 2009 08:30pm | #12

            "These designations refer to a moisture resistance test "

            Here, I was thinkin' it added a little extra safety margin for 1-hour fire walls! ;-)Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.

          3. splintergroupie | Jun 10, 2009 08:21am | #17

            I think FHB did an article in the long-ago on moisture testing wall wrap, including felt and the "new" Tyvek-type materials. I think there were Mason jars and rubber bands involved. <G> I'm not sure what they proved. Me, i use a rain screen...

          4. User avater
            xxPaulCPxx | Jun 09, 2009 09:09pm | #13

            ...uses a moisture sensitive dye as an indicator.

            Great!  So when the paper gets wet, after 30 or 60 minutes blue dye starts leaking from your walls?

             

            ;)

            Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!

            Look, just send me to my drawer.  This whole talking-to-you thing is like double punishment.

          5. splintergroupie | Jun 10, 2009 08:22am | #18

            <...blue dye starts leaking from your walls?>No extra charge for that.

          6. angusj | Jun 10, 2009 10:18am | #19

            Hey guys sounds like I really don't have to worry about the roofing felt.  Here we use the Hals Minute system as one of you explained.  30 min or 60 min.  the same company make the building paper and roofing felt at our lumber yard.  I hear that in the interior of BC they can use 20 min paper.  Never seen it myself.  Here is a link to the products we use,  the product they used is the roof underlayment.  There are sections where we will be leaving that on and sections where it will have to come off.  I thought I would see what you folks thought about it as it wasn't something I had come across.

            http://www.halind.com/content/walls_rainscreen.html

            The upside down vinyl windows have the drain holes on the top.  Drill new holes you say.. could do that however I have seen windows where the blocks they use to help space and hold the glass have not been  installed in the top ( I guess gravity doesn't require upward stops)  besides they have nice little rectangle holes, time consuming to match.

            Discovered today that they didn't have enough power in the house to add the electrical load of the addition. Instead of advising that there would have to be a service upgrade they just disconected things like the heaters in the main house. 

            I think the service upgrade was going to bring an inspector by forsure.

            No smoke detectors installed let alone the required interconnected. 

            New bath fan 50 cfm vents into crawl space.

            Flat roof on addition not enough slope (pudleing), over spanned 2X8 rafters, no venting with fiberglass batts.

            It's endless really.  Water lines are run outside under the house (section of the house on stilts.)  Of coarse they froze so now have wires wrapped around them that plug in for those cold days.  Almost like they forgot the water lines and did that later.

            One of the rooms was built on a slab poured on the dirt and ruble they dug out from the crawlspace.  No concrete bearing walls or footings carrying the over spanned roof loads. just a 3" slab.  They were thinking ahead though,  they I guess realized that they were not going to get the required 8" separation of wood and grade so they put the 6mil poly under the slab left it big and then after framing the walls and putting the 30lb felt in question here on, they pulled that poly up over the felt and stapled it on.  I guess the fact that water runs down the wall when the wind blows it on to the wall hadn't occurred to them.  It's Ok though it can only get three inches deep and then there is a handy escape route under the framing to the inside.  i guess that's why they left the sill gasket out.  Don't want to block that route as well. 

            OK now I'm just venting and getting worked up.  I can't belive that people can get away with this kind of work. 

            We are working on a plan of action with the home owner to help her out.  Thanks for your input on the roofing felt. 

          7. User avater
            Matt | Jun 10, 2009 02:37pm | #20

            So, this stuff was done by "professionals"?

            I think once you get the electrical inspector over there you are gonna open up a can of worms.  Hope the HO has major $$$ to cover all this.

          8. angusj | Jun 11, 2009 07:50am | #22

            yes I have started that proccess today went and saw the building inspector today to get that ball rolling. 

            Speaking of worms.... I was explaining to the home owner why the 2x4 that is structural and is actually touching the dirt was going to rot away, I stuck my finger under it and pulled some dirt out and with it came a big worm. A perfect demonstration.

             

             

          9. FastEddie | Jun 11, 2009 03:05pm | #25

            Wow, I like the turned up poly sheeting.  Never would have thought someone would do that."Put your creed in your deed."   Emerson

            "When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it."  T. Roosevelt

          10. deskguy | Jun 11, 2009 08:15am | #23

            I ordered the red dye paper. Just turn the sprinkler on the kids exterior walls halloween mornin by that night they have great memories that they'll carry with them forever.
            :)

          11. User avater
            xxPaulCPxx | Jun 11, 2009 08:50am | #24

            Wow, that's a great idea.  It's gotta be cheaper than all the acid I'm putting in the kids Kool Aid for Halloween.

             

            They're so cute while they're tripping.  A kindergartner on acid is a sight to behold!

            Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!

            Look, just send me to my drawer.  This whole talking-to-you thing is like double punishment.

          12. User avater
            Matt | Jun 12, 2009 02:13am | #26

            Only in california... :-)

          13. fingersandtoes | Jun 12, 2009 03:06am | #27

            "Odd, since the poster if from British Columbia.

            The reno looks like it's in capable hands, eh?"

            90% of the architectural specs in Canada use minutes rather than the old numbers to designate felt thickness. I'm too lazy to look but I think the latest code does too. My understanding is that they now rely on a certain tested infiltration standard rather than the old "#15" which used to vary widely in quality.

          14. splintergroupie | Jun 12, 2009 03:52am | #28

            The copyright date on that link was 2008, so it looks like their data is dated or just wrong about it being an American test only.

  2. Pelipeth | Jun 09, 2009 01:34pm | #3

    My whole house is covered with 30# felt, doing fine.

  3. JTC1 | Jun 09, 2009 02:20pm | #4

    >>One of the countless mistakes is they papered the building with 30 lb roofing felt. <<

    Sounds like one of the few things they did right to me.

    Difference? A few thousandths of an inch.

    Leave it, it will do just fine.

    Jim 

    Never underestimate the value of a sharp pencil or good light.
  4. seeyou | Jun 09, 2009 03:06pm | #7

    Felt is building paper. Was the standard before some brainiac invented Tyvek and it's competitors. Lots of folks here are going back to it, especially under cedar. Now if the question is #15 vs #30, I've seen both used. I'd prefer and have used #30.

    http://www.quittintime.com/      View Image        

  5. Shep | Jun 09, 2009 03:06pm | #8

    There's nothing wrong with using 30# on the walls. I prefer it these days over 15#. The 15 just seems too flimsy anymore.

  6. mike4244 | Jun 10, 2009 01:58am | #14

    Years ago I used 15lb felt.15lb felt today is much thinner in my opinion. I use 30lb felt all the time now.Sounds like the only thing done right was the 30lb felt.How the heck do you install a window upside down. They must of thought the window sill was a drip edge.

    mike

    1. User avater
      Matt | Jun 10, 2009 03:11am | #15

      Yea - I wanted to hear about the upside window too - and the nit wit who "done it".  I'm guessing it (they?) was/were vinyl with a nailing flange all around.   Seems like the light bulb mighta turned on when they stood back from the newly installed window and noticed the writing on all stickers was upside down... duhhh!!!  So easy even a caveman could do it...

  7. User avater
    Jeff_Clarke | Jun 10, 2009 06:14am | #16

    #30 paper under all 6800 LF of CVG cedar siding here - all doing just fine.

    Jeff

  8. Ehoff | Jun 10, 2009 08:15pm | #21

    Angus

      There is nothing wrong with using 30# felt as a building wrap.  As a matter of fact, the Cedar bureau calls for you to use 30# for cedar siding.  There is some question as to Tyvek/tannin reaction.  My 60+year old home I just resided had 30#felt as the wrap.  I used 30# felt again.

     

    E

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