My house has vinyl siding running along the back of the house and brick along the front. I plan to install rigid foam board along with Tyvek house wrap beneath the siding. Do I place the house wrap on top of or behind the foam board? I’ve noticed that some areas behind the siding have felt paper while other areas do not. Do I need to remove the felt paper when installing the other two products? The foam boards interlock with each other. Will I need to tape these junction points? If I do, what tape do I use. Do I run the boards vertically or horizontally? Do I need to do anything different in the ares where the siding meets the brick?
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Greetings iggy,
This post, in response to your question, will bump the thread through the 'recent discussion' listing again.
Perhaps it will catch someones attention that can help you with advice.
http://www.buildingscience.com/resources/resources.htm
is also a site that might assist you.
Cheers
'Nemo me impune lacesset'
No one will provoke me with impunity
bump
'Nemo me impune lacesset'
No one will provoke me with impunity
Run the Tyvek first - I mean after you get the vinyl off
Then install the foam - use plasticap nails with shank long enough for whatever thickness foam you are installing.
What thickness it that? What kind of foam - Dow or Foil faced? That answer effects next step...
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Iggy,
I think if you're installing rigid board insulation (XPS or Polyiso) on the exterior of the house frame, using a housewrap (Tyvek or equivalent) is unnecessary.
Assuming you're using insulation with shiplapped joints, if you install carefully and tape all the seams with quality sheathing tape (e.g. VentureTape or equivalent... NOT duct tape) you will create a very effective air barrier, which is the primary benefit of a housewrap. I believe housewraps are also used as a secondary drainage plane behind the siding... orienting the shiplapped joints in the insulation appropriately would likely achieve the same thing.
The air permeance of some EPS insulation (e.g. white "beadboard" type) is too high to be considered an effective air barrier, so if this is the material you're looking at using a housewrap would be advisable.
As Piffin eluded to, depending on the climate where you live, the thickness and material type of the insulation need to be considered carefully... the insulation will act as a vapour retarder or vapour barrier, and will have a profound effect on the performance of the building envelope.
Lots of good information over at buildingscience.com... I suggest checking it out.
Regards,
Ewan
Edited 4/7/2006 5:54 pm ET by Ewan
Good points.The biggest problem he is going to have is detailing around windows and doors with custom made J-metal or new trims and keeping the drainage plane shedding water
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I was under the impression that EPS is an air barrier when the seams are sealed, it is not however a vapor barrier, due to it's perm rating of 1+. I don't know if it is rated as a drainage plane?
Garett
Hi Garett,
It seems that air permeability values for XPS and EPS rigid insulation are not normally documented... I suspect largely because it's the permeability of the air barrier SYSTEM, as opposed to any individual component, that has any real relevance.
However, I have read in a couple of documents (not manufacturer's literature) that the lower compressive-strength Type I and Type II EPS insulation have measurable air leakage rates greater than what is normally designated for an air barrier. Of course, as the saying goes, the devil is in the details, and I gather it's the seam sealing and transitions that will make or break an air barrier regardless of the insulation type. I'm not sure about EPS as a drainage plane... I suspect the water absorption is low enough so it would work, but I don't think any rigid board insulation makes for an ideal drainage plane due to the horizontal and vertical joints between boards.Ewan
I live in New Jersey and I am planning to use Owens Corning foamular 250 which is 3/4 inch foam board. In the few areas that do not have felt paper, should I bother in covering these areas with more felt paper or will the foam be enough.