I have recently replaced the vinyl siding on my house with new 7″ shiplap siding. I wrapped my house with 30# felt instead of the standard 15# felt figuring this would help keep the moisture out better. Does anybody think that this will cause any future problems with allowing the house to breath properly.
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Whether it's the optimal choice is a frequent religious argument around here, but it should be fine from a vapor barrier standpoint.
Not that it answers your question, but there is comfort in groups. Our architect specs out 30 lb felt as a best practice over 15 lb or tyvek.
Beer was created so carpenters wouldn't rule the world.
Be happy that you saved some money by using the felt over Tyvek. Let it go. Have a beer.
Best to you and yours, Chris.
Some say I know too much.
good choice- I wouldn't put that expensive garbage Tyvek or the like either.
Like I said, the subject of many religious arguments.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I wonder how long it will be before Tyvek makes a faux felt housewrap. complete with the lines and lapping effect. I'm sure it would be a great seller.
There already is such a product - by another manafacturer - it's called Fortress - or maybe it is Fortify - it looks like felt, but comes in 5' rolls - I think it is. I think it is a little tougher than regular felt too.
It depends on your climate conditions. We are in Houston, Tx and a tyvek style house wrap is a must. Because the warm side of the wall is the outside of the house and the cool side inside because of A/C we need the vapor barrier to be on the outside. Mold here is a big concern and nothing works better than a house wrap versus felt. Unless its stucco, then its felt for sure.
""we need the vapor barrier to be on the outside"" Tyvek is not a vapor barrier. If you are relying on Tyvek to keep water vapor out of the walls it is not going to happen.
It is an excellent vapor barrier. It works like gortex. Its water proof yet allows water in vapor form to excape. Where are you getting your info?
--- Its water proof yet allows water in vapor form to excape. ---That would make it a water barrier, but not a vapor barrier. There's a difference.Rebeccah
Actually Tyvek is a vapor retarder - the distinction is that a vapor barrier has a perm rating of less than 1 whereas a vapor retarder has a perm rating of greater than 1. Personally I feel that behind siding, Tyvek is the best choice, based on cost, performance, and cost of labor to install.
If someone wants to use felt, that is fine too.
Edited 2/4/2007 12:43 pm ET by Matt
Tyvek is an Air Barrier, designed to allow the passage of water vapor , but stop the movement of air and water .
Yes it works the same way as gortex, now imagine that your body is colder than the surrounding air.. the water vapor in the air will penetrate the goretex and condense on your skin.
I prefer felt myself. My goretex rain gearleaks too.
I think you will be fine. Personally I think all this discussion about whether felt or Tyvek is better is pretty academic. The item of central importance is that the house is wrapped and flashed properly before the exterior cladding is applied.
Here are some articles to read:
Leaky Housewraps
Housewraps, Felt Paper and Weather Penetration Barriers
Housewrap Felt or Paper
and this one gives perm ratings for various building materials. Although it does not list #30 felt something unique about felt is that it's perm value increases when it gets wet. Perm value is basically a materials ability to let water vapor pass, thereby allowing a drying action. The higher the perm rating, the higher the drying effect. On the flip side, felt tends to be more waterproof, so the water doesn't get in in the first place, partially because felt tends to seal around nails that penetrate the paper when the siding is installed.
BTW this whole thing about #15 and #30 felt is kind of a moving target. I believe there are no real industry standards to govern the actual performance of these materials, and specifically the perm rating. Notice that I said #15 and #30 as in "number fifteen" and "number thirty". We used to have 15# and 30# - fifteen pound and 30 pound felt. Just like everything else today, manufacturers started cutting back and now we have the #15 and #30 which is more of an indicator than a measurement.
It all comes down to personal preferance.
I deal primarily in new construction so tyvek is the wrap of choice. We apply it while the walls are being built. A nine or ten foot roll is far faster to apply than 15 or 30lb felt. The builder we are working for is trying the newdense armour roof "felt" under the shingles. We'll see how it holds up.
I prefer jumbo-tex 2x, besides it's code here in SFNM.
Got some more info on this "jumbo-tex 2x" stuff? First time I heard of it. I found this web site . Roughly what is the cost? What is the 2x part? It surprises me that a particular product would be required by code. Is most of what is built there in Santa Fe stucco? I see the same manufacturer has a housewrap product called WeatherSmart and from the description it sounds pretty much like Tyvek.
Edited 2/5/2007 6:24 pm ET by Matt
If his shiplap was cedar than felt is better than tyvek. Seem I saw something in FW about tyvek reacting to cedar. Or is this not so?
Hammerelbow
This topic has been round and round. There is no "hard" evidence of cedar reacting with Tyvek, but several anecdotal reports.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin