With the recent heat wave throughout the country and some of the attics I’ve been in the past few days, I’m wondering if anyone has a rule of thumb for how much difference between outside air and temperature in the attic is acceptable. If it gets too hot in the attic, does it matter?
I have a problem when the beer instantly turns to dust.
I do not know where I read it but I believe last year a home inspector died from heat exhaustion .
I think he was able to get back down out of the attic but died in the home .
Any one have more information on this .
Roy Cooke sr
I thought I had read a similar article, and I thought I had saved it, but I can’t find it now. I might have lost it on my hard drive that crashed last August.
Most thermostats for attic fans have a maximum setting of 140°F. That is the same setting I use for determining whether or not I go into the attic to any significant distance. It’s not hard to explain heat-related deaths to Clients; just save all the newspaper stories that appeared in papers this month.
Use that third-party reference (the manufacturer’s maximum thermostat setting) and pull out some stories about heat-related deaths, and recommend more ventilation for the attic, and you’ll probably be okay. Charge a reduced fee (I charge half my original inspection fee) to go back out and inspect things that could not be inspected at the original inspection, or recommend further evaluation by a qualified roofing contractor, who, hopefully, will provide them with additional information about high attic temperatures, as well as options for installing additional ventilation.
I heard 20 degrees from outside to inside.
This was one from last week for me.
Inadequate attic ventilation will result in a reduction of the life expectancy of the roof covering, if asphalt based. Ideally the attic temp should be as close as possible to the outside temp. That is close to impossible on a hot day. If the roof is exposed to the sun on a hot day I will not even walk it, the potential for damage is too great.
Larry
I never walk on roofs, hot, cold, or otherwise.
I like that ideal, too.
I heard there is usually about a 40 degree difference. Can’t remember where I heard it though.
This was in an uninsulated garage wall facing west as the sun was going down, I don’t know what the attic temperature was, probably the same or a little warmer.
150-160 are not uncommon when its 115 in the shade here.
150 is very common here with proper ventilation and the hot sun bearing down on a dark roof!
i would not enter an attic much hotter than 120 degrees because it is difficult to breathe with a resperator on
If it’s hotter than 80°F, Ms Margarita and Dr Cuervo head to the beach, not an attic!
If it’s hotter than 80°F, Ms Margarita and Dr Cuervo head to the beach, not an attic!
If that is the case, you must not be inspecting the roof and/or the attic’s too often. ha. ha.
Marcel 
Attic heat will kill you dead now or later!
You’ll be gone before the Real Estate Agents gets off the phone and realizes you’ve been gone a while!
It does seem like Ms Margarita and Dr Cuervo are always at the beach, doesn’t it. I shall have to put them on a time clock, I guess, to see if they’re carrying their weight around the office here.
I just learned of a Realtor I knew just died of heat exhaustion.His elderly clients asked him to empty their attic of items and he got overheated.He came down out of the attic, got some water,went out on the porch , sat down and died.This happened last week in Wilmington , NC.His obit is here:
http://www.wilmingtonstar.com/apps/pbcs.dll/article?AID=/20060805/NEWS11/60804025/-1/news11
We all need to be aware of the dangers we face everyday.
Safety First.
130 in the attic I was in today.
Some houses here have 2 water heaters and two hvac units in the attic.
I try to inspect those in the am but for afternoon inspections it is really hard. I have to do it in stages on real hot days and drink lots of water early in the day.
Most builders are only using soffit and ridge venting. The ridge venting is sometimes marginal due to length of the vents and lack of proper opening in the sheathing. Sometimes the ridge venting is blocked with felt paper or sheathing. Sometimes the soffit venting is partially blocked with insulation too.