My house was built in the 60s and doesn't have normal plywood sheathing. It has that old sheet-rock-like sheathing (it's black, I think it is exterior gypsum). Basically the walls (right now) go, exterior gypsum > tar paper like stuff > foam board > vinyl siding.

I am not re-sheathing the house, so I am unsure if a house wrap is needed when re-siding. I'm hiring a company to do the siding and the owner said it wasn't necessary to install a house wrap, I was hoping to verify that with someone who knows siding.

  • Where are you located?
    – DMoore
    Oct 21, 2014 at 21:39
  • @DMoore east coast, nyc area
    – justinw
    Oct 21, 2014 at 21:50

4 Answers 4


Building wrap is used as an infiltration barrier. Before materials like Tyvek were widely available, tar paper was used as appears to be the case with your home.

Materials like Tyvek superseded tar paper because their lighter weight allows wider rolls and thus more efficient installation. But tar paper is fine. As with building wrap, proper installation is more important than differences among suitable materials.


Whether or not you want it has nothing to do with siding.

It makes no difference to the siding.

The point of housewrap (brand-neutral) is that it is vapor-permeable air-barrier - as such it can reduce drafts and air movement, and thus potentially reduce your heating and/or cooling costs.

  • As I mentioned to @Dmoore above, right now there seems to be some tar/felt paper on the sheathing; I am wondering if putting tyvek over that is redundant
    – justinw
    Oct 22, 2014 at 3:30
  • IIRC, tarpaper (as opposed to red resin paper) is not vapor-permeable - though this does not matter so much because it has leaky (air-wise) joints every 3 feet. In my area red resin paper was typically used under siding. Housewrap is vapor-permable and 9 feet tall, with joints that can be effectively taped - so it makes a more effective air-barrier, which is the main reason it has taken over from the older products (and some newer sheathings have a bonded surface that can itself be effectively taped and take over from housewrap.)
    – Ecnerwal
    Oct 22, 2014 at 14:55

Being that you are on the upper east coast, I would say yes if you do not currently have a house wrap. This will decrease moisture/air issues and is a good bang for your buck.

I also agree with Ecnerwal - the siding is its own thing - you really need both. If the siding company tells you that you don't need it then it is possible that they believe you have a housewrap performing OK now or that they don't usually do housewraps (or feels like the profit isn't worth it or whatever) and don't want you talking to a siding installer that does.

  • There seems to be some tar or felt paper over the existing sheathing, wouldn't that serve the same purpose as the tyvek?
    – justinw
    Oct 22, 2014 at 3:29
  • 1
    If the tar paper is in good condition then I wouldn't replace it. It serves the same purpose and really the disadvantage of tar paper vs. tyvek is that it tears really easy (when installing - obviously shouldn't tear with siding over it). There is nothing wrong with tar paper as a housewrap if it is in good condition.
    – DMoore
    Oct 22, 2014 at 3:51

I believe if you don't have a moisture problem the way the house sits right now ie. Mold or mildew or popping plaster. Then you don't need the added cost for labor and materials for a siding job.

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