Here in my city starting in 2008 you can not use tyvek when using brick (they found mold in brick/tyvek combination). You have to use 30 lb felt paper (#30) - felt paper is the same they use under the asphalt shingles.

Is the use of house wrap standard in your city? if so, why you need to pay for it as an additional?

I think you need to get a detailed list of specifications before you sign the contract.

No, it's not standard, that's why I asked if we should get it or not.

Thanks

After more than 20 years of building new homes, I'm coming full circle on this.

Appropriate housewraps such as Tyvek can do a wonderful job in conserving energy and providing a drainage plane when they're properly applied. But the Devil, as they say, is in the details. And too many builders and/or their trades get those details not just wrong, but completely backwards. So, at best, the housewrap is useless; at worst, it leads to long-term damage. When I have a choice, I sheathe the home in XPS and forget the housewrap altogether. And, since I almost always build in brick or stone, I let the masons add their felt as they have been doing for a hundred years.

As the sidebar by Paul Fisette in the linked article shows, that's the preference of some leading experts.

If the OP has a choice, it should be to insist on effective window and door pans and window flashings.

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me: Do you have links on the local ban on housewraps?

Here is a link that might be useful: Making Sense of Housewraps

This is an interesting question. I will be using Styrofoam SIS, and was considering adding a layer of housewrap on top. Would that be warranted? As I understand it, the tape that is used to tie the Styrofoam SIS panels can become unglued, causing problems.

Should I use felt paper on the studs before the Styrofoam SIS?

The siding will be some type of fiber cement like cemplank.

Building Science Corp.'s guidelines on sheathing with XPS say a wrap can be used on the outside of the foam, layered between the foam and sheathing or on the studs. However, the preferred location is between the sheathing and foam; that way it's most secure. (See Building Science Corp. RR-0501, particularly page 13.)

If you use housewrap on the exterior of the SIS (structural insulated sheathing) Dow recommends taping those seams and not the SIS seams.

Since no one seems sure how long the tape will last, the key is to wrap the house as continuously as possible with the correct overlapping, i.e., the top layers overlap the bottom ones. So even if all the tape comes undone, the water is still shed.

Building Science Corp. says to use housewrap or building paper. When housewraps were first being used here, the masons still insisted on adding the felt on top. My architect said it certainly didn't hurt to have a second layer on top. And now, when I look at the way the wrap was applied, I see it was a great idea!

In my location, I use a significant capillary break when installing siding, i.e., furring. I would check for local Codes and best practices in your area. (All I know about Oklahoma! comes from show tunes!)

Hi,

I think the answer is follow your local codes. I.E. do what other people have done. I.E. do not be a ginnea-pig for an experiment.

Having said that I think the logic to use it or not depends on humidity and local climate. Tyvek can be thought of as a sports jacket for houses. Consider a mountain jacket like The North Face, these are made with Gortex. Tyvek is like Gortex but for houses.

OK Tyvek allows small water vapour to go through but not liquid water, just like the jacket you wear. So Tyvek works well where you have humid inside and dry outside. Remember water vapor will go in the direction of more vapor to less vapor. Note no one wears a Mountain Jacket in the tropics because the humid outside will go in, hence it is not the effect you want.

Tyvek is therefore good if most of the time your inside of the house is more humid than the outside. So typically colder climates. Water vapor then goes from inside to outside the house. Water liquid remains on the outside.

In a quick test, if you can wear a mountain jacket comfortably for most of the year where you build your house, then use Tyvek. Otherwise maybe not such a good idea.

That's my 2 cents. Note I am not a builder. My house does have Tyvek and I am in New York State.
Best, Mike.