"With the air tight IC recessed light cans you should still build air sealed enclosures around them because they leak a lot apparently. LEDs are a great choice for these locations especially without enclosures as they have a weaker "mini chimney" effect." in all my projects new and existing I've found many ways to seal IC cans. retrofit with inserts. then seal housing to sheetrock ceiling...from inside the house before putting trim kits in place. even 'air tight' trims don't stop the oversized cuts in sheetrock from leaking. I use a mastic tape made by Hardcast #1402 for all my holes in ceiling. more on this later. this seal described above is the best with no measurable air leakage. building boxes..maintaining the 4" air space on all sides & top of can light..also works, cheaper cost..harder install. problem is the 'legs' of the can lights that are attached to ceiling joists & properly sealing around them. this is where the air leakage occurs. I never use foam..because it shrinks over time, you have little control over where it goes & unless it is fire rated..shouldn't be next to heat producing areas. and yeah..I'm overly cautious about this. this method can be well done..and still leaky. foam installs I've seen online in videos put fg batts around recessed lights and foam them. I don't like this at all, and it is never done on my jobs. best of all is to use ICAT only, and use the hardcast tape to seal the cut between housing & sheetrock. Hardcast brand mastic tape #1402 is a 3" wide strong mastic tape. I perfer it over any other brand on the market. cut it into 1 1/2" wide strips and use it in full width depending on size of opening to be sealed. sticks to just about any clean dry surface...to the point of pulling paper off sheetrock if you try to remove it. so use it carefully. opeings at bath fans, supply boxes, stove vents, recessed lights..I use hardcast. use it once..and you'll understand why. not the cheapest on the market @ $22- $35 per 100' roll. but absolutely great stuff. while it is hard to describe the sealing of supply boxes with hardcast from inside the house..a picture shows it well. I'll attach one to this post. flgargoyle .. foil bubble foil is an overpriced product that performs no better than the cheaper radiant barriers. in my house with a tin roof..I have a single sided foil scrim fraft paper like what is used for ductwrap. I used button cap nails to attach it to the undersides of my rafters. with gable end vents..and 3 hurricanes later I've had to do a little repair on it..but it was worth the few bucks it cost me & the 2 mornings it took to install. good benefit in summer little to none in winter. my attic has fg batts on attic floor, one layer in joist bays the other unfaced layer laid across joists. no ducts, no equipment no recessed lights and a damn near perfect air barrier from living to attic space. ducts are in fur downs inside living space, vs air handler in side living space also. a bit over sized @ 2 tons with an whole house april air dehumidifier..also in conditined space. 4" media filter at return. 15SEER unit the addition I re-roofed last summer, batts in rafter bays 1" R-7 foil foam sheating lathes & gavalnized tin. as rafter/ceiling joists are 2x4 (yeah...go figure) the batts are R-13 with the R-7 gives me R-21 for this large bedroom. prior to this install the room was used for storage as it was too hot in summer & too cold in winter and too expensive & uncomfortable to use. with radiant barriers there always has to be a mininum of a 3/4" air space. thus the lathes on top of foil foam board under tin in addition & opposite install in big attic with rb under rafters with foil facing into attic space. gotta run...but wanted to share my take on things. oh here is the pic of the supply sealed from inside the house with hardcast tape. best of luck

Well, idmd, this is just my opinion...I grew up in a one-storey ranch house built in 1958, the roof was hipped but fairly shallow and my dad put insulation batts in the attic, but I'm pretty sure it wasn't up to modern code. This was back in '61 when we moved in, and lived there until '87. We never had moisture problems and had no ridge vent and I don't recall any soffit vents either, although the crawlspace had sliding louvers every six feet or so. My current house is a 1908 two and a half storey frame house with a steep pitched hipped roof with three dormers and two chimneys. It has box gutters, so no soffit vents, and no ridge vent either. There is not one sign of moisture damage in the attic, which is a finished single room which takes up all the territory except for about 5 feet per side for storage under the rafters. The roof is skip-sheathed which meant original roof was slate, but is now asphalt shingles. My guess is that if it has lasted this long without vents, it will last another 100+ years. Old houses, even ones built in the 50s were not so hermetically sealed that moisture was a problem. The biggest problem with moisture from our ranch house was in winter, when ice formed on the aluminum window frames and the marble sills. We tended to put towels on them to catch the water as it melted--this was in the bedrooms, at the far end of the house from the furnace. :)

Sorry, I should have specified my location -- we are just outside of DC, so we typically have hot, humid summers and fairly cold winters. We don't get the extremes of some areas of the country though. I'm encouraged by the comments from both of you. Worthy, thanks for the article. I understood most of it. I think we have done a pretty good job of separating the conditioned living spaces from the unconditioned attic so the underside of the roof stays cool in winter. When it snows, the snow stays on our roof much longer than it does on neighbors' roofs (I always thought this was a good sign that our insulation was working) and we've never experienced any ice dams. We never see signs of moisture or mold in the attic or on things stored there. It does get very hot in the summer. As you climb the stairs from the second floor to the attic, you can feel the temps rise. Our basement used to be very damp, but since we had closed cell insulation sprayed on the rubble stone walls, it feels and smells much drier...if we're keeping the moisture out of the house, the attic should be drier as well, yes? Worthy, I'm thinking and hoping that you are right and that if it has been fine for 108 years and we've improved the envelope, we should be fine. Thanks so much for weighing in.

Hello, The potential issues all depend on how the roof was constructed and also insulated. Assuming the interior ceiling isn't vaulted I'm going to assume their is insulation on the attic floor. Yes, I know you said you have no attic but I think what you mean is that there's no accessible attic space. But unless you're vaulted, there's an attic space. You don't have to ventilate an attic space if it is completely sealed off. Meaning, no roof vents, etc. There's always the potential of condensation building within the attic during hot summers but that damage would be caught during inspection. My guess is that at some point after the home was built they drilled those holes into the attic space to minimize that condensation and it's probably doing an okay job unless you see any leakage/drywall damage on any of the ceiling areas of the home. I don't know Virginia climate as much as west but I'm going to assume it's more humid in the summer so that's your real challenge. There's a lot of varying information on how to ventilate or not ventilate an attic space - so you'll just have to talk to a couple experts on site. I say put an offer in and find a good home inspector that you personally meet at the site to evaluate your concerns. Those guys love to find issues with homes and maybe there is none but that's your best route. If your inspector seems perplexed, find another inspector. If there is a problem and you can put a number to altering the space, the homeowner will have an opportunity to fix the issue. I realize this adds time and stress into the process but will be worth it. The RE agent should make sure there is an inspection deadline and resolution in the purchase contract so you have an 'out' if nobody agrees with inspection/remedy costs, if any. Good luck! Jonah