More recently the term house wrap is usually used to describe plastic fabric wrbs such as tyvek.
Roof felt as house wrap.
Substituting synthetic roof underlayments for housewrap after stripping the original siding from a 30 year old house and preparing to install fiber cement panels a contractor wonders if he can use a waterproof synthetic roofing underlayment instead of housewrap behind the panels.
The original wrb was asphalt impregnated felt paper or tar paper the same material commonly used as an underlayment under roof shingles.
When and why condensation occurs inside buildings explains the problems caused by excessive indoor condensation explains how moisture enters building wall and ceiling cavities and summarizes the best approaches to prevention of indoor moisture and condensation problems.
After the shingles or roofing material is installed the felt is of no effect except as an insulation and it is negligible.
Tar paper or roofing felt is put on a roof to waterproof it until the shingles are applied.
The main advantage of house wrap over felt paper is the superior strength and durability of house wrap.
It s both breathable which will help solve problems with moisture and waterproof.
Here s what an expert had to say.
No you should not use roofing felt as a house wrap for siding but you can use gaf underlayment call deck armor for wrapping the exterior of a home before siding is installed.
House wrap and felt paper when properly installed and undamaged are both weather resistant barriers wrb that create permeable and water and air resistant exterior walls.
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Asphalt felt tar paper the standard requirement is type 1 felt meeting astm d 226 standards.
Then install vertical nailers over the wrapped sheathing and attach the panels to the nailers which will create an air space between the panels and the wall sheathing.
As for using house wrap on a roof there would be nothing wrong with it but i believe it would be more expensive.
In fact there are a number of important ways roofing felt not only protects your roof but also your residence.
The main purpose of the sheathing wrap whether building felt or plastic housewrap is to prevent water leakage into the building structure.
First cover the sheathing with asphalt felt or a nonperforated housewrap like tyvek or typar which will protect the sheathing from moisture but also allow the wall assembly to breathe.
Roofing experts have discovered that adding a layer of protection between your structural roof decking the layer of wood that covers your rafters and your roof shingles helps create a better looking and longer lasting roof.
It is critical therefore to cover the entire shell from roof to foundation including gable ends and band joists and always to lap upper layers over lower layers shingle style to shed water.