Double Felting Low Pitch Roof

Sunday august 5 2018.

Double felting low pitch roof. 21 degrees is a bit low for a slate roof i would contact the felt manufacturer for advice some are ok some are not. Page 1 of 2 1 2 next. The traditional metal roof types such as 5v crimp shown above and corrugated are rated by the manufacturers for use down to a 3 12 pitch three inches of vertical rise for every foot of horizontal run because of the shallow height of the undulating. Roofing at low pitches counterbattens fixed to protect nail tape at the top of the rafters and nail tape over the rafters and other fixing points we all know that roofs are pitched to enable water to run off safely to the gutters without pooling and getting into the building structure.

Roll roofing is different. It looks as if there s no drip edge at the gable ends of the house so if you need to make a determination for sure your main task is not to fall off the ladder while looking under the shingles at the felt. In your cold climate with the possible danger of ice dams a bituminous membrane should suffice. It has just one layer so it goes.

Discussion in builders talk started by mudhut sep 28 2006. Can metal roofing be used on a low slope pitch roof. How to install roll roofing on low slope roofs. Guide to roofing underlayment installation on low slope roofs with asphalt shingles asphalt shingles can be used on roofs with a slope of 2 12 to 4 12 if double coverage underlayment is used.

Align this layer with the bottom of the roof. The roof is low enough slope that double coverage would have made sense. Snap a chalk line the. A typical roof has three layers a felt layer and two layers of overlapping shingles.

Understandably the double felt method has been implemented widely within the industry to overcome low pitch problems. 21 degree pitch double felting. Start with a 19 inch strip of 15 lb. The arma s residential manual for asphalt roofing recommends that asphalt shingles on low slope roofs be applied over a nonperforated single layer of adhesive backed bituminous membrane installed to the manufacturer s specifications or over a double layer of asphalt impregnated felt paper.

The double felt solution has proven to be particularly useful for small roof areas which would be expected to discharge only a limited amount of rainfall. 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. But if you want to use felt paper you need to take additional steps.