My 2nd floor is aprox 15-20 degrees warmer than the 1st floor. Iv been given several options to fix this issue such as adding ceiling fans, additional hvac returns and insulating the attic. I’m considering insulating my attic.

I don’t want to use blown in insulation because the space is easily accessible with a full plywood floor and in the future could be used for storage.

I’m concerned that spray in foam will obviously be permanent but would hide any issues such as leaks or holes and some online info says mold can be an issue.

I’m considering insulating it by self with bats, insulation boards heat barriers etc.

Looking for feedback for anyone who has had their attic insulated.

Is your attic vented?

Are you wanting to put insulation under the plywood flooring or under the roof deck?

I'm trying to imagine a world where you don't have insulation in the attic

Can you do blow in cellulose under the plywood floor?  Will obviously require holes in the floor in multiple places in order to get it in every bay and ensure it gets all the way in.  Sounds like a pain.

Or remove the plywood floor a few pieces at a time and lay in rockwool or good old pink fiberglass?  Reinstall the floor.  That might be the cleanest way.

I'm assuming the attic is vented.

*I'm just a homeowner.

The plywood floor does have pink fiberglass insulation under it. There is a ridge vent and a vent at each end of the attic. I added a fan which brought the max temp down a bit (topped out at 140 and now seems to max out at 120). The floor doesn’t seem to be nailed down. Everything seems to be insulated except the rafters under the roof itself.

If your attic is vented you aren’t supposed to have insulation on the bottom side of the roof deck. Sounds like your vents aren’t working well enough. In theory, the attic should be the same temp as outdoor. The insulation should only be in the floor of the attic to keep from building condensation where you don’t want it.

Edit: this is how new houses are planned, I’ve been in many older houses that were hot in the attic like yours. If the roof is insulated on the bottom side of the roof deck, you shouldn’t have any in the floor of the attic and the attic now becomes a conditioned space and all vents are sealed.

Stick framed or trusses up there?

Not %100 but after some quick googling its Trusses

Iv had a HVAC company and an insulation company come out to take a look. No one has mentioned taking out the insulation that’s in the floor but it’s def something to ask about.

I don’t want to through money away if I can insulated under the roof deck myself with bats of fiberglass insulation.

Also I don’t get a warm and fuzzy feeling about spray foaming since it’s permanent and could hide future issues.

I really don’t know enough to know if that’s reasonable

A picture would help if you’re able. Roof trusses would make getting around a lot more difficult and you said there’s plywood laid down up there so I’m thinking perhaps it’s stick framed and you’re seeing the rafter collar ties.

If you’re able to walk around, I’ll assume stick framed with rafters. If that’s the case, I would install rolls of radiant barrier against the roof decking between the roof rafters, then stable rolls of fiber batts, then screw down sheets of foam board on top. Same thing for the gable walls. Make sure your leave the foam board cut back at the top under the ridge vents and of course don’t cover the soffit or attic venting that’s bringing in air. That will reflect the radiation and also slow down the heat from entering the attic.

You should have free flowing air under the roof deck from the eaves to the ridge.

Check your eaves to ensure they’re not blocked by insulation. There should be cardboard or foam rafter vents that keep insulation from blocking off airflow from the eaves.

This is what I planned on doing if I were to do it myself.

This is what the attic looks like Attached File

Thanks for the picture. Adding that radiant barrier between the rafters against the decking will help a lot.  Be careful how you secure it as to not penetrate the top side of the decking. Depending on the rafter spacing and width of the radiant barrier rolls you get, it’s best to staple them to the rafters and not the decking. The batts and then foam board will be even better but air exchange within the attic is also super important so make sure your entry and extort vents are large enough and unobstructed. Let us know what you end up doing and how it affects the temps upstairs.

I’ve got the same issue with our split level house in Alabama.  AC has plenty of capacity, the issue is inadequate air circulation upstairs.  Resorted to a small high velocity fan at the bottom of the stairs pointed up during the July-August heat.  This year I got a smallish diameter ceiling fan to put above the stairs to help mix the upstairs/downstairs air.  

My attic looks just like yours.  I’ve been considering standing 2x6 or 2x8 on end in the attic like joists and filling the gaps with insulation.  That way if I ever need the storage I can throw down some plywood on the joists and have the attic floor back.

Just ripped out a second bedroom ceiling in a guest house, it was a swirled ceiling with panel board.  Put R30 pink rolls from underneath and fresh drywall for ceiling. Note existing ceiling had half assed r10 and not everywhere.

OP - Do you have ventilated soffit panels? These are critical to allow air movement through the attic up to the ridge vent. As others have stated you must ensure this path from the soffit area into the attic isn't blocked by existing insulation.

Radiant foil battier insulation works well in conjunction with a properly installed ridge vent system.

I have ridge vent, soffit vents, and gable vents.  I added radiant insulation on the west-facing roof to help with the late day sun, it slightly reduced attic temps but made no perceptible difference inside the house.  
On sunny summer afternoons the attic is so hot it's legitimately dangerous.  

OP: your roof trusses look like mine - the bad thing in my situation is the horizontal joist that is the upstairs roof is only 2x4, so there's only 4 inches of insulation on the attic floor.  

I’ll have to get up there and take a look. The other issue I have is really bad ice dams. I was more worried about getting my upstairs temp under control but it would be nice to solve the ice dam issue as well.

If you already have fiberglas insulation under the flooring you may consider adding another layer by putting down 2x4s, insulation and plywood flooring on the top, this would give you double the insulation.
If you have a vented attic insulating the roof won't do anything.

ETA - put the 2x4s sideways and attach them to the trusses, you probably only need to put plywood over the center of the attic for some storage space with the naked insulation at the sides.

I'd fix the ice dam issue first.  It could cost you a roof if you don't.

It's entirely possible the poorly/unevenly insulated ceiling is contributing to the ice dams.  

Here is a decent article that popped up via search of causes and temporary/permanent fixes:  https://extension.umn.edu/protecting-home-rain-and-ice/dealing-and-preventing-ice-dams#take-immediate-and-long-term-action-1977660

We bought our 1974 home in 1998. It had 4" of blow in (R11). I added R19 batts throughout. Used a painters suit, N95. Not a bad job.
ETA: may rafters look just like yours.

Doesn't snow here, but when I added the radiant insulation (the bubble wrap between layers of foil type) to the rafters the roof is visibly colder in winter - where the radiant insulation is the roof frosts over, spots where I could put the radiant insulation do not frost.  
Radiant insulation could help with ice dams by keeping the roof a bit colder so the ice doesn't melt/refreeze as easily.

I'm doing a similar project.  As others have noted, you may only have 4 or 6" of insulation under your plywood.  That's in the R14-R20 range if fiberglass.  Not good.  My house has mostly blown-in cellulose that's 6-8" deep.  It's crap, especially in the summer.  And I've found several large uninsulated areas and gaps allowing attic air into the space between floor joists (2-story house).

I'm putting in radiant barrier stapled to the bottom side of the 2x6 rafters leaving an open channel between rafters from perforated soffit to ridge vent.  I'm using a micro-perforated double-sided product from here.  This stuff is very durable and unlike the cheap foil from the big box stores.  It's a heavy plastic core with metalized film on both sides (and small perforations to allow moisture to move).  You cannot tear it.

Last spring I did about 500 sq ft in a south-facing attic off of my mancave (FROG) and over our dining/kitchen area.  On frosty mornings the difference is obvious looking at the shingles.  Summer attic temps in that area are about 10F lower than before.  I've got an indoor/outdoor thermometer setup in that attic to monitor.

I'm also rolling out unfaced R30 over the existing blown-in stuff to give me something in the R40-R50 range.  As someone else mentioned you need to put a barrier at the bottom of your trusses where they meet the top of the wall so that insulation doesn't block your soffit to ridge flow.  It's a job, but will pay back every month if done well.  Good luck!

I would use Rockwool batts if possible. Easy button is blown in to at least R-38.

Blown-in settles over time and it's easy to leave voids and gaps.  Batts FTW.

From everything you've described, especially the ice dams, you simply don't have enough insulation.  Those trusses are 2x4 and there's plywood laying on them.  That's 3.5" of insulation.  Get rid of the plywood, blow in cellulose, and be done with it.

OP It sounds like you have some compounding issues here.

1. How old is the house?  And have any major renovations occured?

2. Do you have ceiling penetrations/lights (I.E. can lights or surface mount fixtures) in the drywall below?

3. Do you have ventilated soffits or are you relying on the gable vents, ridge, and fan?

4. Tell us more about your HVAC system.  Is it multi zoned, or single zone?

5. Are you wanting to DIY this or hire it out?

6. Are there just batts between the trusses where there isn't plywood?  1 layer or 2 (and is it perpendicular to the trusses?)

I agree with this. If you’re getting ice dams, you’re losing a lot of heat through your ceiling.

Depends on the bottom cord of the truss.  Mine are 2x6s with 2x4's for the rest of the truss.  But yeah gonna need more insulation up there for sure.  Doesn't address everything though.  Sounds like the vents aren't working properly if the fan only knocked it down 20 degrees.  Should be within ~10 degrees of outside if you have it vented properly and mechanically.

A spray foam insulation on the underside of the room is bar far the coolest temperature ive ever experienced while in an attic. But like mentioned already the downside is if you have to do a full tear off of the roof then the insulation is mostly likely going to be destroyed.

Sounds like you probably have poor ventilation, and not enough insulation.

Ridge vents and gable vents don’t work well together. The air takes the path of least resistance, which is entering through the gable and exiting through the ridge. That means only about a 1/4 of the airspace is being vented.  You want airflow across the entire roof, which is air entering through vented soffits and exiting through the ridge.   Quick fix though, as long as you have vented soffits, you just need to cover the gable vents on the inside.

You can either lay unfaced batts on the plywood, or use foam board to make yourself a landing area for storage and then blow in additional insulation. Make sure you allow for airflow through the soffits.

OP , just blow another 12 inches on top of existing plywood. We do it all the time. You can leave a small spot for storage. Those 2x6 or 8s  arrnt thick enough to allow a r38  , which iscwhat you need.