Ventilating hip roofs is something that every roofer one day will have to do. Due to their short ridge lines, properly ventilating these types of roofs in a hip style fashion can be somewhat difficult.
Some problems that may arise when trying to ventilate a hip roof can be that their maybe not enough exhaust ventilation. A 1,200 sq. foot of an attic space needs 17′ of Cobra Exhaust Vent system. You may need to compensate with extra exhaust. Install roof louvers with 12″-18″ of ridge to add exhaust ventilation to the roof system and attic space for proper ventilation needs.

Add five roof louvers on a typical 1,200 square foot attic to reach the needed ventilation for that particular area. Roof louvers are also most commonly called and known as mushroom vents, soldier vents, air hawks, cake pans, and box vents.

When installing the exhaust vents make sure you know if the roof has ridge boards or not. Leave a 6″ of uncut sheathing at the gable ends. Leaving the 6″ protects the structure from wind driven rains. Cut the sheathing only for safety and structural integrity, set the correct blade depth. Cover the entire ridge with the cobra exhaust vent for weather protection, best appearance, and to prevent dead-air pockets, cover the entire ridge with ridge vent.

When using ridge ventilation, do not cover the ridge vent slot/opening with leak barrier material or other underlayments. Caulk the lengths together. If larger lengths are needed, caulk the ends to seal them together. Install the ridge cap shingles over the cobra exhaust vent. Use the cobra smart nails supplied with every package that you purchase of the cobra exhaust venting system.

Match the caps to the shingles. Install the ridge caps with equal or longer warranty than main shingles. Ado not over drives the nails when installing the exhaust vents. Leave a ¾” between the ridge cap and the deck. Over driving can leave an uneven ridge profile. When installing over laminated shingles, caulk the underside of the outer baffles to the shingles to completely seal them together. Important, do not install any ridge-type vent along the down slope hip rafters, or hip legs.

Many roofers like to use a special cobra nail gun to install the nails. This ensures that you are getting the secure and safe fasten that you need for the exhaust vents to stay in place since inclement weather can quickly rip them off the roof.