Attic access: What is the best way to maintain an airtight seal?
Once again, I’m a guy building a house–someday. After my seemingly endless perusal of this website, I’ve concluded that (a) attics can’t be drywalled off and forgotten, even though I won’t ever want to go up there, and, (b) an oft-sold accessory, the pull-down attic stairs, is a really bad idea for an energy-efficient home. Given these facts, can anyone suggest a simple, airtight detail which will allow attic access and maintain the integrity of the building envelope?
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1. Provide exterior attic access by means of an exterior door at the gable wall, accessible only with a ladder by service personnel. This method is preferred by energy geeks. No attic storage! No easy access!
2. Provide a generously sized attic access hatch in the ceiling of your upstairs hallway -- NOT in the ceiling of a closet. This access hatch can be built from a SIP scrap, or can be site-built with plywood and multiple layers of rigid foam. Provide weatherstripping at the perimeter and secure it with cam-action latches on all four sides.
Concur with Martin's second alternative though have used an alternative way to secure the foam lid. We run 4 eyebolts through the lid facing downward, one in the middle of each side near the perimeter. To the eyes on the bolts, we attach tension springs, about 3-4" long, available at local hardware store. At the end of the spring are simple barn door hooks which latch to eye hooks in the scuttle hole. This provides adequate tug to compress the weather seal strips, and give a reasonably good seal.
We have used 2 products for this. The first and most used is the Rainbow Attic Ladder. It is a walk up solution and has double weatherstripping and the panel is foam filled which gives R-15. Not enough, but much, much better than anything comparable for a walk up. It's thermal value can be augmented just like a standard attic ladder, but it does provide an air-tight seal. It is a sturdy painted steel unit and I'm a fan.: http://www.rainbowatticstair.com/attic-stairs-products/prestige-folding-attic-stairs.cfm
For just a hatch, the Skuttle Tight provides R-40.: http://www.skuttle-tight.com/cieling_applications.html
Perfect. Muchas Gracias.