Roofing Questions

My house has a roof with a 2 1/2:12 (11 degrees) slope. The manufacturer says it’s okay to use asphalt shingles, but my contractor says it isn’t. Who’s right?

2017-12-06T11:25:39+00:00 December 6th, 2017|

There are some manufacturers (and even model building codes) that will allow the application of asphalt shingle roof having that slope; however, NRCA does not recommend shingles on slopes less than 4:12 (18 degrees). Asphalt shingle roof systems are watershedding and rely on gravity and roof slope to effectively drain water off the roof.

My contractor suggested installing a ridge vent on my roof and I already have two single static vents. Do I really need a ridge vent?

2017-12-06T11:24:42+00:00 December 6th, 2017|

NRCA suggests the amount of attic ventilation be balanced between the eaves and ridge. The intent of a balanced ventilation system is to provide nearly equivalent amounts of ventilation area at the eave/soffit and at or near the ridge. For a balanced ventilation system to function properly, approximately one-half of the ventilation area must be [...]

Are two layers of No. 15 underlayment the same as one layer of No. 30 underlayment?

2017-12-06T11:22:48+00:00 December 6th, 2017|

No. Two layers of underlayment are referred to as a "double-layer of underlayment" and there is a 19-inch overlap between layers. One layer of underlayment is called a "single-layer of underlayment" and there is 2 inches of overlap between layers. NRCA recommends a double-layer of underlayment for roof decks having slopes of 3:12 (14 degrees) [...]

One contractor’s bid includes No. 15 underlayment and another contractor says he only uses No. 30 because it’s the best. Who is right?

2017-12-06T11:21:48+00:00 December 6th, 2017|

For asphalt shingles, NRCA recommends a single layer of No. 15 asphalt-saturated underlayment be used with roofs having slopes of 4:12 (18 degrees) or greater. For roof slopes between 3:12 (14 degrees) to 4:12 (18 degrees), NRCA recommends a minimum of two layers of No. 15 underlayment. If you are installing a heavier-weight shingle with [...]

What is the best asphalt shingle to use on my roof?

2017-12-06T11:21:05+00:00 December 6th, 2017|

Asphalt shingle material performance depends of the quality, quantity and compatibility of asphalt fillers, reinforcements and surface granules. There are two kinds of asphalt shingles (based on the type of reinforcement mat used); fiberglass and organic. Fiberglass shingles are more fire- and moisture-resistant than organic shingles. Organic shingles have good wind resistance, high tear strength [...]