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.
Roof felt as house wrap.
A high quality house wrap like barricade building wrap is more resistant to ripping and tearing during installation than felt paper.
After the shingles or roofing material is installed the felt is of no effect except as an insulation and it is negligible.
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.
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.
As for using house wrap on a roof there would be nothing wrong with it but i believe it would be more expensive.
More recently the term house wrap is usually used to describe plastic fabric wrbs such as tyvek.
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.
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.
Why use roofing felt paper.
Tar paper or roofing felt is put on a roof to waterproof it until the shingles are applied.
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.
The original wrb was asphalt impregnated felt paper or tar paper the same material commonly used as an underlayment under roof shingles.
It s both breathable which will help solve problems with moisture and waterproof.
The main advantage of house wrap over felt paper is the superior strength and durability of house wrap.
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.
Asphalt felt tar paper the standard requirement is type 1 felt meeting astm d 226 standards.
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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.