The loft area is a sauna during the day, you'll start sweating immediately and literally have a heat stroke if up there for too long. I installed 2 tiny gable vents at the front / back for airflow but I cant tell a difference.

Im preparing to install foam boards between the rafters for my roof insulation (2nd pic), this will leave a 1.5" air gap between the metal roof and foam board.
Would this alleviate my pizza oven loft area and keep the hot air outside or are there venting options I should look in to? Theres a lot of debate on forums about different techs and ways to approach this.
BTW the metal roof ends are completely sealed off to protect against the elements / insects.

>>2926189 (OP)
>why is this uninsulated room so hot?

>>2926189 (OP)
lol it's a metal roof with zero insulation and a fucking tiny vent. so yeah insulate it. You can also paint it reflective white to cool it. small vent like the wont do shit, you could put a small fan on it to push out hot air I guess.

I'm a retard so I'd 24 huge vents

have you given any thought to mylar/aluminum foil?
your roof is thermally conductive, so it is pissing Infared. A second reflective layer not excited by the sun should reduce em. i would staple under the rafters creating large air pockets i would not seal it.
are you sure it is the roof and not the walls?
concrete curing produces lots of heat for a few months.

>>2926317
This. Put a layer of aluminium to reflect IR back (the roof reflects it but heats up thus becomes another source of IR). Then insulate. Then fed up for still having 85F and install AC.

Anon you're always going to be fighting massive thermal transfer, adding mylar/aluminum foil isnt going to do shit. From the lighting it looks like your eaves are open.

If you really want to fight the heat you need to elevate that metal roof and put it on a deck of insulation. As thick as possible.

https://www.youtube.com/watch?v=T05c6ZQy2dI
https://www.youtube.com/watch?v=Qhs52h8f51Q
https://www.youtube.com/watch?v=8ly8X_bCUXw

Vents aren't going to do shit here. You want actual airflow, you need windows and preferably, fans and/or an air conditioner. That's after you insulate that shit as per other anons.

>>2926189 (OP)
get two fans pushing air in and one fan twice the CFM pushing air up and out. problem solved.

>>2926189 (OP)
Seeing as /DIY/ has the reading comprehension of a 40 year old roofer, I'll try and answer your question. Yes, the insulation will help a ton. Personally I overheat anytime there isn't any airflow so a solar fan blowing out would be the next step if the insulation isn't enough.

Airflow. Fan bringing cool air in, and fans up high in the gable ends blowing the hot air out. Whirly birds might help too though they're pretty useless imo

There's a spray paint/foam that I've seen used by people here to externally insulate a roof, and if course internal insulation should help alot

>>2926189 (OP)
>I installed 2 tiny gable vents at the front / back for airflow but I cant tell a difference.

Minimum recommended vent area is 1:150 of the attic's area, so if your shack is 200 square feet the sum of open vent area should be at least 1.33 sqft.

>Im preparing to install foam boards between the rafters for my roof insulation (2nd pic), this will leave a 1.5" air gap between the metal roof and foam board.

If installing boards at rafters you need to close those vents you installed at gables since they would bypass the insulation.

>Would this alleviate my pizza oven loft area and keep the hot air outside or are there venting options I should look in to?

Ideally the air gap is vented to outdoors (ridge and eave venting)
Polystyrene is not great when exposed to high temperature because it releases toxic styrene fumes, and the insulation will be isolating heat at the air gap since it no longer escapes into the shack, so that top surface of the foam will be extra hot.

Since you are not doing a cathedral ceiling and you already have gable vents, I don't see why you wouldn't insulate horizontally at the ceiling level as with a conventional attic.

get some shiny foil up there to reflect that radiant heat away.

>>2926189 (OP)
didn't we already have this thread?
i remember seeing this pic and writing a reply a few months ago
insulation will make temperature more comfortable
you need a gap between insulation and the metal sheets to allow air flow. the purpose of that air flow is to allow moisture to escape. therefore the area between the insulation and metal needs to be vented to the outside world. not sealed.
if you had a warm roof layup (insulation ON the joists and then metal ON the insulation (no wood touches metal) ) then you don't need a gap because theres nothing to rot. you can actually buy roof sheets with insulation glued to them for this reason. but because the wood is there it will rot so you are fucked.

>>2926189 (OP)
>>2926192
>those tiny vents for a space that size
You're the kind of guy who would keep tripping a breaker and would "fix" it by fastening something over it to keep it in place.

Radiant barrier aka aluminum foil as others have said. Its relatively cheap and easy to install.
Insulation won't stop radiant heat as well and that is probably where most of your heat gain comes from.

>>2926189 (OP)
Insulation and better ventilation like anons said above, but also picrel is a lifesaver in such a situation
Just make sure you have a good large open window or vent for cross ventilation so the thing will pull air out
Believe me these things work wonders

>>2926415
kinda interesting looks a bit weird but straightforward