This felt or rubberized asphalt sheet provides an extra layer of protection between your shingles and your roof deck.
How many layers roofing felt.
You wan walk over the roof to remove any air bubbles that may form.
However in almost all areas it is not acceptable to install more than two layers of roofing on any commercial building.
The first course starts with an extra 1 2 wide run.
So anywhere along the gable end that you can see the felt you ll see two layers.
Align this layer with the bottom of the roof.
On roof slopes of 2 12 to 4 12 the remainder of the roof shall be two layers of 15 felt applied in shingle fashion or 1 layer of ice dam protection.
These thick layers of roofing felt are installed by heating the back of the felt with a butane torch and then carefully applying it to the roof.
You will be placing the second layer of felt over this.
It helps reduce blow off by allowing your shingles to lay flatter and more uniformly.
Installing the roofing felt does take care but can go very quickly.
Before adding the second layer though spread a thin layer of adhesive on the first layer using your trowel.
Assuming your roofing contractor is using standard 36 wide 15 roofing felt double coverage means that each layer of felt put down across the roof laps 19 over the upper half of the previous course.
On 4 12 or greater slopes the balance of the roof shall be one layer of 15 felt.
There needs to be an overlap in the felt to help increase the water tight quality.
Snap a chalk line the.
Though the requirement is 2 layers 15 felt in my area northern california the roofers spec 30 whether for 2 layer low slope or 1 layer normal high slope.
Five best practices reasons for using roofing felt underlayment.
For many years it was acceptable to put even the third layer.
Additionally it prevents wind driven rain from getting under your shingles and causing damage to your roof structure or the inside of your.
Of course how many rolls you need will depend on the size of the roof so ensure you measure correctly.
The key to weatherproofing your flat roof is adding a total of 3 layers.
Anderson tecnatorch sbs torch on mineral felt capsheet is used as the final layer of the felt roofing process.
It s available in rolls that are 8m long and 1m wide with a thickness of 4 2mm mineral or 3 8mm sand.
Overlay a second layer of felt 2 to 3 inches and fasten it through the overlay so it secures the top of the felt underneath.
If i were you i d at least follow up with that roofer on why they chose to spec 2 layers felt just for piece of mind and in case he turns out to be the better roofer or not.
Add the second layer.
Thus you will repeat the earlier steps.
A third layer of felt needs to be placed.
This will help the two layers adhere to each other.
