Replies

1. 
   ptp | Apr 19, 2008 02:30pm | #1

   30# felt.

1. 
   paperhanger | Apr 19, 2008 02:45pm | #2

   Really? No tyvek? This is on the weather side of the house, the white cedars curled up unbelievably after only 8 years. I want to do this right this time.

1. 
   gb93433 | Apr 19, 2008 07:57pm | #4

   Anytime I installed wood siding I always back primed the material and have never had a problem in over 30 years. In fact a few years ago a new owner hired a contractor to add onto a building I built. After 23 years the siding I installed was in great shape and it was bare on the front. The contractor added onto the building and the siding I installed years ago is still straight and flat while the new siding is cupped. The contractor did not back prime the new material.If you back prime the back then the water can come and go in only one direction. The water will tend to move to the dry area of the front when the sun dries the front.

2. 
   GRCourter | Apr 19, 2008 04:01pm | #3

   Did you back prime, or even better, dip the shingles in Cop-r-Tox?  Eight years, I just did some reflashing on a 78 year old house that is all cedar shingles.

3. 
   Bing187 | Apr 19, 2008 08:48pm | #5

       Pre-primed clap a must, I can't believe anybody does clap w/out it anymore, unless they're going au-natural with the outside.

       I wouldn't go felt under the clap, tho, even 15#. I'm happy w/ Typar, mostly due to the  fact that it's ok to leave exposed longer than Tyvek.

            Utimately, my belief is that from a weather infiltration standpoint, Good flashing, tight joints, good finish, and phenoseal should keep moisture ( from rain ) from ever getting to the housewrap anyway. Pre-primed stays nicer longer till you get a coat of >>>>>>whatever on it.

   Bing

   
   

   ---

   Edited 4/19/2008 1:54 pm ET by Bing187

4. 
   mike_maines | Apr 19, 2008 09:22pm | #6

   Tyvek doesn't perform as well as some other housewraps, like plain old tarpaper or Typar.  Plus there are reports that the acids (tannins) in the cedar actually dissolve the Typar over time.

   Typar with "Homeslicker" membrane adhered to it is probably the best easy way.  Tarpaper is second best but plenty good enough.

5. 
   Dinosaur | Apr 20, 2008 02:48am | #7

   ptp gave you the right answer in post #2: use 30-lb. felt.

   Cedar is one of the most active aromatic wood species, and all the issues of its chemical inter-reactivity with modern synthetics like Tyvek, et al., have yet to be discovered, of that you can be sure. But builders have been using felt under cedar for over a hundred years with no problems, and it works as well or better than the modern synthetic membranes to repel wind and water.

   Seems like a no-brainer to me.

   Dinosaur

   How now, Mighty Sauron, that thou art not brought
   low by this? For thine evil pales before that which
   foolish men call Justice....
   

   

6. 
   Pelipeth | Apr 20, 2008 02:51am | #8

   Ditto on the 30# felt.

1. 
   paperhanger | Apr 20, 2008 02:26pm | #9

   Looks like the 30# felt is the ways to go. The white cedars where installed over typar and stapled. The shingles were stained and the weather has beat the snot out of them. Shrinkage is over 1/4 inches and there is considerable cupping going on , and some shingles are loose. Off they come today.

1. 
   Bing187 | Apr 22, 2008 01:57am | #10

           I wont argue the point as to white cedars and felt; if you asked me what to put under cedar shingles, I would respond 15# felt...... White cedar shingles in general are garbage and I steer people away from them on a regular basis. Tell ya what, put new white cedars over 30# felt and see what they look like in 5-10 years. Like ####. I like Typar, haven't heard the same "tannins break down the paper " arguement with it that I have with Tyvek.Whichever way ya go... good luck

   Bing

1. 
   paperhanger | Apr 22, 2008 02:06am | #11

   Thanks Bing, I started ripping the white cedar shingles off, there is typar under them and in good shape. Here's a question. I'm banging in all the staples and am going to slash the typar and reinstall new typar over that. Do you think that will cause any problems?

1. 
   Bing187 | Apr 22, 2008 03:00am | #12

            I don't see why it would, but why slash it? If it's supposed to keep vapor travelling in one direction, it should just offer that much more protection from elements. There may be other folk here with some reason or insight as to why it would cause a problem, but if it's tight, intact, and there's no moisture issues underneath ( mildew or damp areas on osb/ply) I would think leave it.

   Bing

2. 
   Dinosaur | Apr 22, 2008 03:02am | #13

   You've got me confused. Two posts ago, you agreed that felt was the way to go. Now you're saying you're going to install new Typar over the old Typar...?

    

   Dinosaur

   How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....

3. 
   Bing187 | Apr 22, 2008 03:19am | #14

               Just curious TH why do you dislike the housewrap products out there besides felt? I agree felt under shingles, but I really don't ever recall a good looking white cedar job lasting a long time. Even on the "shingle style" houses so popular on the cape, it's the "quaintness" of the old, curled, black white cedars that people seem to like, (not myself, mind you) I really doubt the condition of his shingles has as much to do with what's under them as it has to do with what they are. And before you ask, yes, I've stripped white cedars off with 30# felt under them, and they were just as nasty as the other houses I've seen with wc on them. I also ( and this actually surprises me ) have been by houses that I sidewalled my first summer swinging a hammer, ( with RED cedars r+r's) 25 years ago now, that we papered with red rosin paper ,of all things,that look fantastic. They've been well maintained, and still look great. Imagine that. Without " cedar breather, or any other of the trick new things out there. Musta we got lucky. :) A couple hundred times. Peace

   Bing

4. 
   Dinosaur | Apr 23, 2008 06:17am | #15

   I wouldn't say that I 'don't like' Tyvek/Typar &c; I used Tyvek on my own place when I re-built it in '95 (although, admittedly at that time I was taking more advice than I was giving, and not all of what I was told turned out to be correct) and, in the appropriate circumstances I would probably use it again. It has certain advantages over felt for certain types of applications.

   What I would say is that in the case of cedar shingles, felt has the advantage over the new housewraps for a couple of reasons.

   First there is the issue of the chemical inter-reactivity between the olefins used in making these housewraps and the aromatic oils in the cedars. Yes, red cedar contains more aromatics than does white, but the eastern white cedars still have enough zing to it to kill mites and moths quite dead, so I don't think it's safe to discount this issue.

   Second, to do the best job you can of shingling that wall, you should interleaf each course of shingles with felt, just as you would for a wood shingle or shake roof. This will bring any water that gets behind the shingles back out to the surface almost immediately, and help promote quicker drying. Once you decide to do that you lose one of the perceived advantages of using 9'-wide synthetic housewrap...which is that you can just 'wrap' the whole house and then cut out the windows and doors. On a shingle job, you can't do that, so you might as well use 3-foot-wide felt which is easier to handle anyway (especially if you're working alone).

   Finally, felt is cheaper. I haven't priced a roll of Tyvek recently, but last time I bought one it cost me 10 cents per square foot, as opposed to 3 cents per square foot for felt (the same year). Okay, so you won't save enough to do the roof in #1 resawn heavies--but you oughta be able to bankroll a few cases of Guiness with the difference....

   Dinosaur

   How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....

5. 
   Piffin | Apr 23, 2008 01:23pm | #16

   No need to slash the old stuff. It is already well perforated, but more the old double VB concern does not apply here. Both plies of Typar are in the same plane with nothing trapped between them.The concern about modern housewrap should not apply either, in theory. it is Tyvek and not Typar that has been observed to deteriorate in contact with cedar tannins, and the backpriming of the new clapboards will prevent direct contact anyways. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

6. 
   paperhanger | Apr 24, 2008 12:56am | #17

   Thanks, Piffin, so you have no reservations about the fingerjointed preprimed red cedar claps?

7. 
   Piffin | Apr 24, 2008 03:50am | #18

   No, not me 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

8. 
   paperhanger | Apr 24, 2008 12:26pm | #19

   good, I value your opinion.